Terms Starting with "O"

732 terms

O

O in psychophysical testing, abbreviation for observer.

O data

O data other data: information about an individual gathered from the observations, judgments, and evaluations of third parties who know him or her personally, such as family and friends. See also L data; Q data; T data.

O variable

O variable see organic variable.

O-X-O

O-X-O shorthand for a one-group pretest–posttest design, in which the researcher observes and measures a single set of participants (O), introduces an intervention (X), and then measures the participants (O) again to determine whether the intervention resulted in any change.

O’Connor v. Donaldson

O’Connor v. Donaldson a 1975 lawsuit in the U.S. Supreme Court in which it was determined that people cannot be involuntarily committed to a facility on the basis of mental illness alone if they are not dangerous to themselves or others and are able to survive safely outside the facility. A lower court ruling in this case assisted an Alabama District Court in its final ruling in Wyatt v. Stickney (1972) regarding right to treatment with involuntary commitment (see forced treatment; Wyatt v. Stickney decisionwyatt-v-stickney-decision).

O&M

O&M abbreviation for orientation and mobility. See orientation and mobility training.

OA

OA abbreviation for Overeaters Anonymous.

OAEs

OAEs abbreviation for otoacoustic emissions.

Obamacare

Obamacare n. see Patient Protection and Affordable Care Act.

obedience

obedience n. behavior in compliance with a direct command, often one issued by a person in a position of authority. Examples include a child who cleans his or her room when told to do so by a parent and a soldier who follows the orders of a superior officer. Obedience has the potential to be highly destructive and ethically questionable, however, as demonstrated in the behavioral study of obedience. See constructive obedience; destructive obedience. —obedient adj.

obesity

obesity n. the condition of having excess body fat resulting in overweight, variously defined in terms of absolute weight, weight–height ratio (see body mass index), distribution of subcutaneous fat, and societal and aesthetic norms. The basic causes are genetic, environmental, behavioral, or some interaction of these. Overeating may have a psychological cause (see binge-eating disorder; food addiction; night-eating syndrome), but in some cases, it may be due to an organic disorder (see hyperphagia). Obesity predisposes one to heart disease, diabetes, and other serious medical conditions (see morbid obesity), and obese individuals may develop emotional and psychological problems relating to body image. Therapeutic approaches to obesity include diets, exercise programs, nutritional education, drug therapy, behavior modification of eating patterns, hormonal treatment when indicated, group support, hypnotherapy, and psychodynamic psychotherapy focused on insight into the nonconscious purposes served by the individual’s excessive food intake. Bariatric surgery, or gastrointestinal surgery to reduce nutrient intake and absorption in order to induce weight loss, may also be performed in individuals with morbid obesity. —obese adj.

object

object n. 1. an entity in the environment (i.e., a thing, person, or condition) that acts as a stimulus and elicits a response from an organism; that is, a stimulus object. 2. the focal target of attention, perception, or some other process. 3. the “other,” that is, any person or symbolic representation of a person that is not the self and toward whom behavior, cognitions, or affects are directed. 4. in psychoanalytic theory, the person, thing, or part of the body through which an instinct can achieve its aim of gratification. See object cathexis; object relations. 5. the person (real or imagined) who is loved by an individual’s ego: his or her love object. 6. in linguistics, a noun, pronoun, or complex noun that is governed by an active transitive verb or a preposition, such as dinner in I ate dinner or I came after dinner. Objects of verbs can be divided into direct objects (e.g., cake in Mary ate the cake) and indirect objects (e.g., Mary in John gave Mary the cake).

Object Assembly test

Object Assembly test a performance subtest in the Wechsler Adult Intelligence Scale that accesses the ability of the participant to construct an object from component pieces that only fit together properly if joined in the correct sequence.

object cathexis

object cathexis in classical psychoanalytic theory, the investment of libido or psychic energy in objects outside the self, such as a person, goal, idea, or activity. Also called object libido. See cathexis.

object choice

object choice in psychoanalytic theory, the selection of a person toward whom libido or psychic energy is directed. See anaclitic object choice; narcissistic object choice.

object color

object color color attributed to a solid object, as opposed to a film color, which has no object associated with it.

object constancy

object constancy 1. in object relations theory, the ability of an infant to maintain an attachment that is relatively independent of gratification or frustration, based on a cognitive capacity to conceive of a mother who exists when she is out of sight and who has positive attributes when she is unsatisfying. Thus, an infant becomes attached to the mother herself rather than to her tension-reducing ministrations; she comes to exist continuously for the infant and not only during instances of need satisfaction. This investment by an infant in a specific libidinal object indicates that he or she no longer finds people to be interchangeable. 2. see perceptual constancy.

object display

object display a single display that uses a meaningful shape to present different types of information simultaneously. Object displays usually take the form of polygons, changes in the shape of which provide an indication of the status of the system (see emergent feature). Also called configural display.

object identity

object identity see identity.

object language

object language a type of computer programming language that emphasizes data rather than processes. Unlike imperative languages, with programs that consist primarily of commands to perform specified actions, object languages support programs that consist primarily of commands to data objects generally to modify themselves (e.g., change their values).

object learning

object learning the process of making a connection or association between one aspect of an object (e.g., the color of dark chocolate) and another (e.g., the taste of dark chocolate).

object libido

object libido see object cathexis.

object loss

object loss in psychoanalytic theory, the actual loss of a person who has served as a good object, which precedes introjection and is involved in separation anxiety. Anxiety about the possible loss of a good object begins with the infant’s panic when separated from its mother. In this perspective, adult grief and mourning are related to object loss and separation anxiety in infancy and childhood, which often intensifies and complicates the grief reaction.

object love

object love in psychoanalytic theory, love of a person other than the self. It is a function of the ego and not the instincts as in object cathexis. See love object.

object of consciousness

object of consciousness 1. the perceived object as distinct from the perceiver. The separation of observer and observed is criticized as artificial in some phenomenological philosophies (see phenomenology). In Buddhism and Vedanta philosophy, there is a related notion that the distinction between the perceived object and the perceiving self is illusory. 2. anything of which the mind is conscious, including perceptions, mental images, emotions, and so forth, as well as the observing ego, or “I,” of subjective experience. Compare subject of consciousness.

object of instinct

object of instinct in classical psychoanalytic theory, that which is sought (the external aim, such as a person, object, or behavior) in order to achieve satisfaction (the internal aim). See aim of the instinct.

object permanence

object permanence knowledge of the continued existence of objects even when they are not directly perceived. According to Jean Piaget, object permanence develops gradually in infants during the sensorimotor stage of cognitive development. Milestones that indicate the acquisition of object permanence include reaching for and retrieving a covered object (about 8 months), retrieving an object at Location B even though it was previously hidden several times at Location A (the A-not-B task; about 12 months), and removing a series of covers to retrieve an object, even though the infant only witnessed the object being hidden under the outermost cover (invisible displacement; about 18 months). Recent research using nonreaching tasks suggests that infants display some knowledge of object permanence at an earlier age than that suggested by Piaget.

object play

object play play that involves the manipulation of items in the environment, such as banging toys together, throwing them around, or arranging them in specific configurations. It is one of three traditionally identified basic types of play (the others being locomotor play and social play) and may occur in a solitary or social context.

object relations

object relations 1. an individual’s relationship to his or her entire external world. 2. in psychoanalysis, an individual’s relationships to his or her objects (real and imagined), that is, the persons, activities, or things that function as sources of connection as well as libidinal or aggressive gratification.

object relations psychotherapy

object relations psychotherapy a form of psychoanalysis derived from object relations theory; it recognizes the importance of an individual’s early fantasies of and experiences with significant others (objects), especially parents, and aims to identify the internalized objects within the patient.

object relations theory

object relations theory any psychoanalytically based theory that views the need to relate to objects as more central to personality organization and motivation than the vicissitudes of the instincts. These theories developed from and in reaction to classic Freudian theories of psychodynamics. Some theories—for example, Fairbairnian theory and the approach of Melanie Klein—view the personality as organized in terms of a complex world of internal object representations and their relationships with each other.

object-based attention

object-based attention a mode of visual attention operating primarily on objects rather than on spatial locations. Compare space-based attention.

object-location memory

object-location memory the ability to remember the location of objects in the environment (e.g., where one put one’s car keys).

object-superiority effect

object-superiority effect in visual perception tasks, the finding that judgments about a briefly presented line are made more efficiently when the line is part of a drawing of a three-dimensional object than when it is part of a two-dimensional figure. See configural superiority effect; word-superiority effect.

objectification

objectification n. see reification.

objective

objective 1. adj. having verifiable existence in the external world, independently of any opinion or judgment. 2. adj. impartial or uninfluenced by personal feelings, interpretations, or prejudices. Compare subjective. 3. n. something that is to be obtained or worked toward. See aim; goal. 4. n. in linguistics, see accusative. 5. n. the lens or lens system in an optical instrument, such as a microscope. Also called object glass; objective lens; object lens.

objective anxiety

objective anxiety see realistic anxiety.

objective competitive situation

objective competitive situation a situation in which one or more people evaluate the performance of an individual or team by comparing it either with the performance of another individual or team or with some standard of excellence.

objective elaboration

objective elaboration the tendency to generate particular evaluative responses based on the strength of the arguments contained in a message rather than on factors external to the arguments. See also biased elaboration; biasing factor; elaboration.

objective indicator

objective indicator a marker or other measure of an entity, condition, emotion, or behavior that is free of subjective bias; that is, it is not an opinion or rating but an independent measure. An objective indicator is generally viewed as more reliable than a subjective assessment.

objective prior

objective prior see prior distribution.

objective psychology

objective psychology an approach to psychology that focuses on measurement of behavioral processes or other observable phenomena. Compare subjective psychology.

objective psychotherapy

objective psychotherapy a treatment procedure developed primarily for use with institutionalized patients and patients with mild-to-moderate emotional disturbances. To reduce the subjectivity resulting from a personal relationship with the therapist, all therapeutic communication is carried out in writing. The patient answers written autobiographical questions, relates and comments on dreams, and reacts to assigned readings. In return, the therapist gives interpretations and points out underlying motivations in written memoranda, including a memorandum as a whole, which summarizes all the insights reached in the process. [developed by U.S. psychoanalyst Benjamin Karpman (1886–1962)]

objective reality

objective reality the external world of physical objects, events, and forces that can be observed, measured, and tested. See reality.

objective reference

objective reference 1. the activity or condition by which one term or concept is related to another or to objects in the world. 2. the actual object or sensation that is perceived by the senses.

objective responsibility

objective responsibility in the moral judgment typical of children under the age of 10, the idea that the rightness or wrongness of an act is based almost exclusively on its material result, without consideration of the individual’s motives for doing it. For example, accidentally breaking five cups is worse than deliberately breaking one. Compare subjective responsibility. [proposed by Jean Piaget]

objective scoring

objective scoring scoring a test by means of a key or formula, so that different scorers will arrive at the same score for the same set of responses. It is contrasted with subjective scoring, in which the score depends on the scorer’s opinion or interpretation of participant responses to items.

objective self-awareness

objective self-awareness a reflective state of self-focused attention in which a person evaluates himself or herself and attempts to attain correctness and consistency in beliefs and behaviors. This involves the viewing of oneself as a separate object, acknowledging limitations and the existing disparity between the ideal self and the actual self. Objective self-awareness is often a necessary part of self-regulation.

objective set

objective set a Gestalt psychology factor in which the original grouping seen in a display based on objective factors, such as spatial location, will be maintained as the display changes and will continue to be seen when the grouping is objectively ambiguous. See perceptual set.

objective test

objective test a type of assessment instrument consisting of a set of items or questions that have specific correct answers (e.g., How much is 2 + 2?), such that no interpretation, judgment, or personal impressions are involved in scoring. True–false tests are an example. In contrast, short-answer and essay examinations are subjective tests.

objectivism

objectivism n. 1. the position that judgments about the external world can be established as true or false independent of personal feelings, beliefs, and experiences. 2. in ethics, the position that the ideals, such as “the good,” to which ethical propositions refer are real. Objectivism holds that ethical prescriptions do not reduce to mere statements of personal or cultural preference. Compare subjectivism. —objectivist n., adj.

objectivity

objectivity n. 1. the tendency to base judgments and interpretations on external data rather than on subjective factors, such as personal feelings, beliefs, and experiences. 2. a quality of a research study such that its hypotheses, choices of variables studied, measurements, techniques of control, and observations are as free from bias as possible. Compare subjectivity.

objectivity illusion

objectivity illusion the tendency of people to see themselves as more impartial, more insightful, and less biased than others. For example, someone who likes a particular song might think that his or her opinion is based on objective reasoning and assume that the opinion of someone who dislikes the song is subjective and biased. Various studies have shown that people are aware of the objectivity illusion and can recognize it in others yet fail to identify the phenomenon in their own judgments. See also bias blind spot.

obligate carrier

obligate carrier an individual whose parent and child or whose monozygotic twin carries a particular genetic mutation, implying that the individual must also carry the mutation, even though he or she has not been tested for it.

obligation schema

obligation schema see pragmatic reasoning schema theory.

oblique

oblique adj. describing a set of axes that do not form right angles; in graphical representations of mathematical computations (such as factor analysis), this indicates correlated (not independent) variables. Compare orthogonal.

oblique rotation

oblique rotation a transformational system used in factor analysis when two or more factors (i.e., latent variables) are correlated. Oblique rotation reorients the factors so that they fall closer to clusters of vectors representing manifest variables, thereby simplifying the mathematical description of the manifest variables. It is one of two types of factor rotation used to identify a simpler structure pattern or solution, the other being orthogonal rotation.

OBM

OBM abbreviation for organizational behavior management.

obnubilation

obnubilation n. clouding of consciousness or stupor.

obscenity

obscenity n. verbal expressions, drawings, gestures, and written material that grossly violate the norms of good taste and decency in a given society. See pornography. —obscene adj.

obscurantism

obscurantism n. 1. opposition to scientific inquiry, rational argument, and the progress of knowledge generally, especially when these appear to contradict a given set of political, social, or religious convictions. 2. a deliberate or strategic failure to be clear and lucid in the expression of knowledge or opinion. —obscurantist adj.

observation

observation n. 1. the careful, close examination of an object, process, or other phenomenon for the purpose of collecting data about it or drawing conclusions. See controlled observation; naturalistic observation; participant observation. 2. a piece of information (see data). —observational adj.

observation coding system

observation coding system a scheme or list of mutually exclusive labels, categories, and so forth—each of which characterizes a coherent dimension of interest—used for classifying information obtained by observing others. It is an essential component of any observational study as it clarifies what data should be collected and how, providing definitions of each code along with examples. For instance, a researcher investigating infant behavior might develop the following observation coding system: (1) quietly alert, (2) crying, (3) fussing, and (4) sleeping. Thus, for every time during a specific observation period that an observer sees the baby acting alert, he or she would record a 1 on his or her data form; for every time the observer sees the baby crying, he or she would record a 2, and so forth.

observation delusion

observation delusion see delusion of observation.

observation hold

observation hold the confinement of a person to a hospital by a court order for a limited period of observation, usually to determine competency to stand trial or overall legal competence.

observational learning

observational learning 1. the acquisition of information, skills, or behavior through watching the performance of others, either directly or via such media as films and videos. Also called vicarious learning. 2. the conditioning of an animal to perform an act that it observes in a member of the same or a different species. For example, the mockingbird can learn to imitate the song patterns of other kinds of birds. Also called vicarious conditioning. See also modeling theory.

observational study

observational study research in which the experimenter passively observes the behavior of the participants without any attempt at intervention or manipulation of the behaviors being observed. Such studies typically involve observation of cases under naturalistic conditions rather than the random assignment of cases to experimental conditions: Specially trained individuals record activities, events, or processes as precisely and completely as possible without personal interpretation. Also called observational design; observational method; observational research. See also naturalistic observation.

observed variable

observed variable see manifest variable.

observed-score equating

observed-score equating see score equating.

observer

observer n. 1. one who makes or records an observation. 2. one who is the subject of, and who attends to presented stimuli in, psychophysical testing. In this sense, the term is abbreviated O. See also ideal observer. 3. in telepathy experiments, a participant who is neither the designated sender nor the designated receiver. His or her function is often to guard against experimenter bias or other methodological errors.

observer bias

observer bias any expectations, beliefs, or personal preferences of a researcher that unintentionally influence his or her recordings during an observational study. See experimenter effect.

observer drift

observer drift gradual, systematic changes over a period of time by a particular observer in his or her application of criteria for recording or scoring observations. See experimenter drift.

observer memory

observer memory an autobiographical memory that one remembers from the perspective of an outside observer. When retrieving an observer memory, the person sees himself or herself as an actor in the event. Also called third-person perspective memory. Compare field memory.

observing response

observing response behavior that results in the presentation or clarification (e.g., enhanced view) of discriminative stimuli.

obsession

obsession n. a persistent thought, idea, image, or impulse that is experienced as intrusive or inappropriate and results in marked anxiety, distress, or discomfort. Obsessions are often described as ego-dystonic in that they are experienced as alien or inconsistent with one’s self and outside one’s control (though this is not necessarily the case in children). Common obsessions include repeated thoughts about contamination, a need to have things in a particular order or sequence, repeated doubts, aggressive or horrific impulses, and sexual imagery. Obsessions can be distinguished from excessive worries about everyday occurrences in that they are not concerned with real-life problems. The response to an obsession is often an effort to ignore or suppress the thought or impulse or to neutralize it by a compulsion. See obsessive-compulsive disorder. —obsessional adj. —obsessive adj.

obsessional type

obsessional type see libidinal types.

obsessive behavior

obsessive behavior behavior characteristic of obsessive-compulsive personality disorder or obsessive-compulsive disorder, such as persistent brooding, doubting, ruminating, worrying over trifles, or cleaning up and keeping things in perfect order.

obsessive-compulsive disorder (OCD)

Sorry, "obsessive-compulsive-disorder-ocd" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

obsessive-compulsive personality disorder

obsessive-compulsive personality disorder in DSM–IV–TR and DSM–5, a personality disorder characterized by an extreme need for perfection, an excessive orderliness, an inability to compromise, and an exaggerated sense of moral responsibility (see scrupulosity). Also called compulsive personality disorder.

obstruction method

obstruction method an experimental technique in which a nonhuman animal is presented with one or more goals of various drives—for example, food (hunger) versus water (thirst)—and is required to overcome an obstacle (e.g., an electrified grid) in order to reach the goal. The delay before attempting to overcome the obstacle, as well as the animal’s choice of which goal to pursue, may be used to represent drive strength and drive dominance.

obstructive hydrocephalus

obstructive hydrocephalus see noncommunicating hydrocephalus.

obstructive sleep apnea

obstructive sleep apnea see breathing-related sleep disorder; sleep apnea.

obstruent

obstruent adj., n. see plosive.

obtrusive idea

obtrusive idea an obsessive, unwanted, and alien idea that intrudes on a person’s normal flow of thought. See also obsession.

obturator

obturator n. 1. any item that blocks an opening. 2. a prosthesis worn inside the mouth to close an opening in the palate. It is often used to improve the speech production of an individual with a cleft palate.

OCB

OCB abbreviation for organizational citizenship behavior.

Occam’s razor

Occam’s razor the maxim that, given a choice between two hypotheses, the one involving the fewer assumptions should be preferred. In other words, one should apply the law of parsimony and choose simpler explanations over more complicated ones. See also elegant solution. [William of Occam or Ockham (c. 1285–1347), English Franciscan monk and Scholastic philosopher]

occasion setter

occasion setter in classical conditioning, a stimulus that is differentially paired with a stimulus–stimulus contingency. For example, after presentation of a light, a tone might be followed by the delivery of food. In the absence of the light, the tone is not followed by food. If the tone is effective in eliciting salivation only after the light is presented, the light is designated as an occasion setter.

occasion setting

occasion setting pairing of cues so that one signals when the other will be reinforced. Also called facilitation.

occasional cause

occasional cause in the doctrine of occasionalism, a change in a material or mental condition that appears to cause a correlated change in some other condition but that, in reality, is merely an occasion for God to produce the observed change in the latter.

occasionalism

occasionalism n. the philosophical doctrine that events are not directly caused by the antecedent events that appear to produce them, and particularly that material things cannot cause mental phenomena or mental phenomena influence material things. Rather, all things material and mental are caused by God’s volitional acts. A change in a mental or material condition provides God with the occasion to produce a change in some other mental or material condition. Thus, the material or mental phenomena that might appear to be real and direct causes are merely occasional causes. Extreme forms of occasionalism reject causal influence of any mental or material phenomena on any others. Occasionalism was first formulated by French philosopher Nicolas Malebranche (1638–1715), largely as a response to the mind–body problem arising from Cartesian dualism. —occasionalist adj.

occipital cortex

occipital cortex the cerebral cortex of the occipital lobe of the brain. See visual cortex.

occipital lobe

occipital lobe the most posterior (rearward) subdivision of each cerebral hemisphere, roughly shaped like a pyramid and lying under the skull’s occipital bone. It contains several visual areas that receive and process visual stimuli, and it is involved in basic visual functions (e.g., visual acuity; contrast sensitivity; perception of color, form, and motion) as well as higher level ones (e.g., figure-ground segregation based on textural cues). A region of it, the occipital face area (OFA), has been identified as crucial to face recognition. See also fusiform gyrus.

occlusion

occlusion n. 1. an obstruction or closure. Occlusion of a cerebral artery may cause a thrombotic or embolic stroke. 2. the simultaneous firing of two branches of the same neuron, which may result in a total output that is less than the sum of the separate responses. —occlusive adj.

occult

occult adj. mysterious, incomprehensible, or secret. The term is mainly applied to certain esoteric traditions of magical belief and practice (see magic) but is sometimes used in reference to other alleged phenomena that cannot be explained in either everyday or scientific terms, such as premonitory dreams, clairvoyance, and telepathic communications (see telepathy). —occultism n. —occultist n.

occupation

occupation n. 1. a family of jobs that involve the performance of similar tasks and have similar requirements in terms of skills, training, and personal attributes. For example, accounting jobs in different organizations will differ to some extent in the tasks performed and level of skill required, but there is enough commonality to place them in the same occupation. See also profession. 2. in rehabilitation, see occupational therapy. 3. more generally, any activity or pastime. —occupational adj.

occupational ability

occupational ability the ability to perform vocational or professional tasks, generally measured by a series of occupational tests.

occupational adjustment

occupational adjustment the degree to which an individual’s abilities, interests, and personality are compatible with a particular occupation. The term differs from vocational adjustment in its emphasis on the interaction between an individual’s personal characteristics and the objective requirements, conditions, and opportunities associated with the job.

occupational analysis

occupational analysis the systematic collection, processing, and interpretation of information concerning specific occupations.

occupational biomechanics

occupational biomechanics see biomechanics.

occupational counseling

occupational counseling an early 20th-century approach to vocational guidance. Three steps were identified in the process: (a) relevant knowledge of self, (b) realistic knowledge of occupations, and (c) true reasoning in making sensible choices. [proposed by U.S. educator Frank Parsons (1854–1908)]

occupational cramp

occupational cramp painful spasm of the muscles, usually in the hand or arm, that prevents the individual from engaging in an occupation, such as writing, driving, sewing, playing a musical instrument, or firing a gun. It is a form of dystonia. See musician’s cramp; writer’s cramp. See also repetitive strain injury.

occupational culture

occupational culture a distinctive pattern of thought and behavior shared by members of the same occupation and reflected in their language, values, attitudes, beliefs, and customs. For example, police officers can be regarded as having a distinct culture of this kind. See also organizational culture.

occupational disease

occupational disease any disease arising from factors involved with an individual’s job.

occupational ergonomics

occupational ergonomics a specialty area of ergonomics that attempts to make work systems and processes within particular occupations more responsive to the physical, cognitive, and psychosocial characteristics of workers.

occupational health psychology

occupational health psychology a specialty within psychology devoted to understanding workplace sources of health, illness, and injury and the application of this knowledge to improve the physical and mental well-being of employees.

occupational interest measure

occupational interest measure see interest test.

occupational neurosis

occupational neurosis a psychogenic inhibition in which the individual experiences distress and increasing aversion to work, which may be expressed as poor work performance or reactive symptoms of illness (e.g., fatigue, vertigo) that increase in severity as the individual continues to work. In some cases, there is a specific inhibition that interferes with the ability to work, often affecting an essential function necessary for that work, such as writer’s cramp, seamstress’s cramp, or carpal tunnel syndrome. These inhibitions were originally believed to be conversion symptoms reflecting inner conflicts but have increasingly been found to have a medical explanation. Also called occupational inhibition.

occupational norm

occupational norm the average or typical score obtained from tests of a particular ability, trait, or interest among members of a particular occupation.

occupational psychology

occupational psychology see industrial and organizational psychology.

occupational rehabilitation

occupational rehabilitation see vocational rehabilitation.

Occupational Safety and Health Administration (OSHA)

Sorry, "occupational-safety-and-health-administration-osha" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

occupational segregation

occupational segregation the extent to which people of the same gender or ethnicity are employed in some occupations to the exclusion of others. For example, the fact that a high proportion of nurses are women could suggest that this may be a sex-segregated occupation.

occupational status

occupational status the degree of esteem accorded to members of an occupation by society. Occupations that are viewed positively are high-status occupations, whereas occupations that are viewed negatively are low-status occupations.

occupational stress

occupational stress a physiological and psychological response to events or conditions in the workplace that is detrimental to health and well-being. It is influenced by such factors as autonomy and independence, decision latitude, workload, level of responsibility, job security, physical environment and safety, the nature and pace of work, and relationships with coworkers and supervisors.

occupational test

occupational test a test designed to measure potential ability or actual proficiency in a given occupation. See employment test; work-sample test.

occupational therapy (OT)

Sorry, "occupational-therapy-ot" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

OCD

OCD abbreviation for obsessive-compulsive disorder.

oceanic feeling

oceanic feeling an expansion of consciousness beyond one’s body (limitless extension) and a sense of unlimited power associated with identification with the universe as a whole. According to psychoanalytic theory, this feeling originates in the earliest period of life, before the infant is aware of the outside world or the distinction between the ego and nonego. Oceanic feelings may be revived later in life as a delusion or as part of a religious or spiritual experience.

oceanic state

oceanic state a condition of perceived boundlessness of the self, sometimes involving a feeling of omniscience. It may be an ecstatic state, a state of altered awareness, a state of interpersonal connection or spiritual union, or a dissociative experience. See also altered state of consciousness; cosmic consciousness. [introduced by French writer Romain Rolland (1866–1944) and developed by Sigmund Freud]

octave

octave n. the interval between two sounds that have a frequency ratio of 2:1. See cent; musical interval.

octave effect

octave effect in conditioning, the phenomenon in which a nonhuman animal, after experiencing reinforcement at one sound frequency, will react to a new frequency an octave away from the original frequency because it is more similar to the original than a frequency within the octave would be.

ocul-

Sorry, "ocul" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

ocular

ocular 1. adj. relating to the eye. 2. n. the eyepiece of a microscope.

ocular accommodation

ocular accommodation see accommodation.

ocular apraxia

ocular apraxia see oculomotor apraxia.

ocular dominance

ocular dominance a response characteristic of neurons in the striate cortex. Many neurons respond more vigorously to stimulation through one eye than they do to stimulation through the other eye.

ocular dominance column

ocular dominance column a vertical slab of striate cortex in which the neurons are preferentially responsive to stimulation through one of the two eyes. It is important for binocular vision. Ocular dominance columns for each eye alternate in a regular pattern, so that an electrode inserted tangentially to the cortical surface encounters neurons that are responsive to stimulation through first the ipsilateral eye, then the contralateral eye, then back to the ipsilateral eye; vertical electrode penetration of one column encounters neurons in all layers in which the response is dominated by stimulation through the same eye. Compare orientation column. See also monocular rearing. [first described in the 1960s by U.S. neurophysiologist David Hubel (1926–2013) and Swedish neurophysiologist Torsten Wiesel (1924– )]

ocular dominance histogram

ocular dominance histogram a graph that portrays the strength of response of a neuron to stimuli presented to either the left eye or the right eye. It is used to determine the effects of manipulating visual experience.

ocular dysmetria

ocular dysmetria inability to direct saccadic eye movements (see saccade) to targets. Eye movements may either fall short of the target (undershooting: ocular hypometria) or go beyond it (overshooting: ocular hypermetria). Ocular dysmetria may be due to an oculomotor deficit (e.g., paralysis of eye muscles), defective visual localization, or impaired visuomotor coordination. Also called saccadic dysmetria.

ocular flutter

ocular flutter a rapid horizontal oscillation occurring in both eyes when gazing straight ahead. Flutter may also appear following a saccade (flutter dysmetria). Ocular flutter is typically caused by injury to the cerebellum.

ocular hypertelorism

ocular hypertelorism see hypertelorism.

ocular myopathy

ocular myopathy see myopathy.

ocular palsy

ocular palsy see oculomotor palsy.

ocular pursuit

ocular pursuit see visual pursuit.

oculo- (ocul-)

Sorry, "oculo-ocul" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

oculocerebral-hypopigmentation syndrome

oculocerebral-hypopigmentation syndrome a rare hereditary disorder marked by eye anomalies, absence of hair and skin pigmentation, intellectual disability, and spasticity. First identified in 1967 in three siblings of an Old Order Amish family, the syndrome is believed to be due to an autosomal recessive trait that becomes manifested through consanguinity (relationship by blood).

oculocerebrorenal syndrome

oculocerebrorenal syndrome a rare X-linked recessive disorder affecting male children and marked by renal-tubule dysfunction and eye disorders, including congenital glaucoma, cataracts, and distension of the eyeball because of fluid accumulation. The renal disorders include acidosis, hypophosphatemia, and excess amino acids in the urine. Many individuals with the syndrome have delayed development, and intellectual ability ranges from normal to severely impaired. Neurological deficits vary from absence of brain abnormalities to hydrocephalus and cerebral atrophy. Also called Lowe oculocerebrorenal syndrome; Lowe syndrome.

oculogravic illusion

oculogravic illusion an illusory displacement of an object that may occur when the direction of gravity changes (e.g., a line may appear to tilt in an aircraft during a roll).

oculogyral illusion

oculogyral illusion the apparent movement of a stationary faint light in a dark room when the observer rotates around it, due to involuntary, rapid movements of the eyeballs (vestibular nystagmus).

oculogyric crisis

oculogyric crisis prolonged fixation of the eyeballs in a single position for minutes to hours. It may result from encephalitis or be produced by certain antipsychotic drugs. Also called oculogyric spasm.

oculomotor apraxia

oculomotor apraxia a condition in which willed (i.e., purposeful) eye movements are impaired. Affected individuals appear to have lost the ability to move their eyes. Smooth-pursuit eye movements and saccades are impaired or even absent when elicited by a target stimulus and when the individual is asked to follow a target. A particular form of oculomotor apraxia is lid apraxia, the inability to close the eyes. Also called ocular apraxia. See also congenital oculomotor apraxia.

oculomotor changes

oculomotor changes a broad category of effects induced by alteration of the visual environment, such as the adaptation in movement trajectory that occurs with prolonged viewing of the world through prism goggles that invert or displace the visual image.

oculomotor nerve

oculomotor nerve the third cranial nerve, which contains both motor and sensory fibers and innervates most of the muscles associated with movement and accommodation of the eye and constriction of the pupil (i.e., all the muscles of the eye except the external rectus and superior oblique muscles). Also called cranial nerve III.

oculomotor nucleus

oculomotor nucleus a nucleus in the brainstem that is associated with either of the oculomotor nerves.

oculomotor palsy

oculomotor palsy paralysis of any of the extrinsic eye muscles. This may be due to damage to the muscle itself (myogenic), the motor end plate (neuromuscular), or the third, fourth, or sixth cranial nerves (neurogenic). The most common causes are diabetes, hypertension, and multiple sclerosis. Also called ocular palsy.

oculosympathetic paralysis

oculosympathetic paralysis see Horner’s syndrome.

oculovestibular response

oculovestibular response eye movements that occur when the head is moved. They are used to test integrity of the reticular activating system after brain injury.

Od

Od n. see Reichenbach phenomenon. OD 1. n. a colloquial name (an abbreviation) for an overdose, most often of an opioid or a sedative. 2. vb. to take an overdose. 3. abbreviation for organizational development.

OD

odd–even reliability

odd–even reliability a method of assessing the reliability of a test by correlating scores on the odd-numbered items with scores on the even-numbered items. The correlation coefficient between the two halves is adjusted using the Spearman–Brown prophecy formula, which accounts for the decreased size of the odd and even item sets compared to the test as a whole. Odd–even reliability is a special case of split-half reliability.

oddity from sample

oddity from sample a procedure similar to matching to sample except that reinforcement is arranged for responding to a stimulus that does not match the sample stimulus. Also called oddity learning.

oddity problem

oddity problem a learning task in which a nonhuman animal is required to choose an object or stimulus that is in some way different from a target or other possible choices. The purpose is to test the animal’s ability to perceive relationships and differences among a number of similar objects.

odds

odds n. the ratio of the probability of an event occurring to the probability of the event not occurring, usually expressed as the ratio of two integers (e.g., 3:2).

odds ratio (OR)

Sorry, "odds-ratio-or" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

odor

odor n. the property of an odorant that is perceptible as a sensory experience produced by stimulation of the olfactory nerve. See smell.

odor prism

odor prism see Henning’s odor prism.

odorant

odorant n. an airborne volatile substance that produces an odor sensation. Odorants may differ in both intensity and quality.

odorant-binding protein

odorant-binding protein any one of a small family of proteins that bind to odorants and are carriers of the odorant molecules to the mucus-covered neurons in the olfactory epithelium.

odorimetry

odorimetry n. see olfactometry.

odorvector

odorvector n. the vapor of an odorant, which produces sensations of smell. The odorvector may be sensed via the nose (see orthonasal olfaction) or via the nasopharynx (see retronasal olfaction). Also called odorivector.

Odyle

Odyle n. see Reichenbach phenomenon.

oedipal conflict

oedipal conflict see Oedipus complex.

oedipal phase

oedipal phase in the classical psychoanalytic theory of Sigmund Freud, the later portion of the phallic stage of psychosexual development, usually between ages 3 and 5, during which the Oedipus complex manifests itself. Also called oedipal stage.

Oedipus complex

Oedipus complex in classical psychoanalytic theory, the erotic feelings of the son toward the mother, accompanied by rivalry and hostility toward the father, during the phallic stage of psychosexual development. Sigmund Freud derived the name from the Greek myth in which Oedipus unknowingly killed his father and married his mother. Freud saw the Oedipus complex as the basis for neurosis when it is not adequately resolved by the boy’s fear of castration and gradual identification with the father. The corresponding relationship involving the erotic feelings of the daughter toward the father, and rivalry toward the mother, is referred to as the female Oedipus complex, which is posited to be resolved by the threat of losing the mother’s love and by finding fulfillment in the feminine role. Although Freud held the Oedipus complex to be universal, most anthropologists question this universality because there are many cultures in which it does not appear. Contemporary psychoanalytic thought has decentralized the importance of the Oedipus complex and has largely modified the classical theory by emphasizing the earlier, primal relationship between child and mother. Also called oedipal conflict; oedipal situation. See also castration complex; nuclear complex.

OEP

OEP abbreviation for olfactory evoked potential. See chemosensory event-related potential.

OFA

OFA abbreviation for occipital face area. See occipital lobe.

off cells (OFF cells)

Sorry, "off-cells-off-cells" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

off response (OFF response)

Sorry, "off-response-off-response" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

off-center bipolar cell

off-center bipolar cell a retinal bipolar cell that is inhibited by light in the center of its receptive field but is excited by light in the surround. See also off response. Compare on-center bipolar cell.

off-center ganglion cell

off-center ganglion cell a retinal ganglion cell that is inhibited by light in the center of its receptive field but is excited by light in the surround. See also off response. Compare on-center ganglion cell.

off-center/on-surround

Sorry, "off-center-on-surround" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

off-label

off-label adj. denoting or relating to the clinical use of a drug for a purpose that has not been approved by the U.S. Food and Drug Administration. Manufacturers cannot promote drugs for off-label uses, although medical literature may support such uses.

off-the-job training

off-the-job training interventions to increase the knowledge, skills, and abilities of employees that occur away from the workstation or workplace, often in classroom settings. Compare on-the-job training. See also vestibule training.

off-time life events

off-time life events events that occur at a nontypical or unexpected point in the lifespan for members of a given population. Examples are cancer in a child and marriage for a 90-year-old. Compare on-time life events.

officer selection

officer selection see military officer selection.

officer training

officer training military courses used to educate officers in leadership skills.

officer-assisted suicide

officer-assisted suicide see suicide by cop.

offline group

offline group a group that meets face to face in a conventional setting and uses traditional methods of communication rather than computer-based technology. Compare online group.

ogive

ogive n. the somewhat flattened S-shaped curve typically obtained by graphing a cumulative frequency distribution. Consider the example of test results from students in a classroom. Cumulative frequency values would be given along the vertical y-axis and obtained test scores along the horizontal x-axis. The plot would increase slightly at either end, indicating that few students received very low or very high scores, but rise much more steeply in the center, indicating that the majority of students received average scores.

Ohm’s law

Ohm’s law the principle that the ear can analyze complex tones into a series of individually perceptible pure tones. [Georg Simon Ohm (1787–1854), German physicist]

oikofugic

oikofugic adj. having or relating to an urge to travel or wander from home. See dromomania; nomadism.

oikomania

oikomania n. see ecomania.

oikotropic

oikotropic adj. affected with homesickness or nostalgia for home.

OKR

OKR abbreviation for optokinetic reflex.

olan

olan n. see myriachit.

olanzapine

olanzapine n. an atypical antipsychotic used for the treatment of acute mania, schizophrenia, and other psychotic disorders in adults. It is closely related to clozapine but lacks the latter drug’s association with agranulocytosis. Common side effects are sedation, lethargy, weight gain, and orthostatic hypotension. Rarely, like all antipsychotics, it may be associated with tardive dyskinesia or neuroleptic malignant syndrome. U.S. trade names: Zydis; Zyprexa.

old-fashioned racism

old-fashioned racism see modern racism.

old-old

old-old adj. see adulthood.

Older Adult Resources and Services

Older Adult Resources and Services a questionnaire used as a community assessment tool to determine the level of functioning of older adults in five areas: mental health, physical health, social resources, economic resources, and activities of daily living. It must be administered by a trained individual. Either the entire questionnaire or one or more segments are given. The questionnaire can be used to evaluate existing services or the need for services for individuals or communities.

oldest old

oldest old see adulthood.

Oleptro

Oleptro n. a trade name for trazodone.

olfactie

olfactie n. a unit for measuring odor intensity, used to calibrate early olfactometers. It is equal to the intensity of an odorant that just exceeds the absolute threshold.

olfaction

olfaction n. the sense of smell, involving stimulation of receptor cells in the olfactory epithelium (located in the nasal passages) by airborne volatile substances called odorants. Specifically, olfactory receptors extend numerous cilia into the olfactory mucosa in the roof of the nasal cavity; these cilia, together with villi of supporting tissue cells, form a layer of hairlike projections. Molecules of odorants are absorbed into nasal mucus and carried to the olfactory epithelium, where they stimulate the receptor sites of the cilia. The olfactory receptors carry impulses in axonal bundles through tiny holes in the cribriform plate, the bony layer separating the base of the skull from the nasal cavity. On the top surface of the cribriform plate rests the olfactory bulb, which receives the impulses and sends them on to the periamygdaloid cortex. —olfactory adj.

olfactometer

olfactometer n. an instrument used to regulate the presentation of odorants. An olfactometer may have tubes that are inserted into the nostrils, or the odorant may be emitted more diffusely into the air surrounding the nose. See blast olfactometer; stream olfactometer.

olfactometry

olfactometry n. the measurement of the acuity of smell. Also called odorimetry.

olfactophilia

olfactophilia n. sexual interest in and arousal by body odors, especially those from the genital areas.

olfactorium

olfactorium n. a test chamber devised for precise measurement of olfactory function, especially odor sensitivity. The highly controlled environment of the chamber presents pure air or odorant-bearing air. The testee typically bathes and then puts on a protective suit prior to entering the chamber.

olfactory adaptation

olfactory adaptation a decrease in olfactory sensitivity subsequent to stimulation of the sense of smell. This temporary phenomenon is measured by increases in odor thresholds and reported declines in odor intensities.

olfactory area

olfactory area a brain structure associated with the sense of smell. See periamygdaloid cortex; pyriform area.

olfactory brain

olfactory brain see pyriform area; rhinencephalon.

olfactory bulb

olfactory bulb a bulblike ending on the olfactory nerve in the anterior region of each cerebral hemisphere. This first synapse in the olfactory system picks up excitation from the nose, specifically from the cilia in the olfactory epithelium. See also tufted cell.

olfactory cell

olfactory cell see olfactory receptor.

olfactory cilium

olfactory cilium a hairlike structure arising from an olfactory receptor.

olfactory cortex

olfactory cortex a three-layered area of cerebral cortex at the base of the temporal lobe that is attached to the olfactory bulb and devoted to the sense of smell. The olfactory cortex receives and interprets information from olfactory receptors in the nasal cavity and is involved in the identification of odors.

olfactory cross-adaptation

olfactory cross-adaptation a reduction in sensitivity to an odor following adaptation to another odor. Unlike other senses, there are usually no changes in the perceived quality of single odorants following adaptation to other single odorants. Cross-adaptation is observed, however, in an odorant mixture that contains the single odorant adapting stimulus.

olfactory dysfunction

olfactory dysfunction any alteration in the perception of odor quality or odor sensitivity, such as anosmia, hyperosmia, hyposmia, parosmia, phantosmia, and troposmia.

olfactory encoding

olfactory encoding see visual encoding.

olfactory epithelium

olfactory epithelium an area of olfactory receptors in the lining of the upper part of the nose. The epithelium is separated from the olfactory bulb by the cribriform plate, through which the receptor cells synapse with cells in the olfactory bulb.

olfactory eroticism

olfactory eroticism pleasurable sensations, particularly of an erotic nature, associated with the sense of smell.

olfactory evoked potential (OEP)

Sorry, "olfactory-evoked-potential-oep" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

olfactory hallucination

olfactory hallucination a false perception of odors, which are usually unpleasant or repulsive, such as poison gas or decaying flesh.

olfactory mucosa

olfactory mucosa the superior portion of the nasal cavity containing mucus-secreting cells and subsuming the olfactory epithelium, the olfactory nerve, and supporting cells.

olfactory nerve

olfactory nerve the first cranial nerve, which carries sensory fibers concerned with the sense of smell. It originates in the olfactory lobe and is distributed to olfactory receptors in the nasal mucous membrane. Also called cranial nerve I.

olfactory receptor

olfactory receptor a spindle-shaped receptor cell in the olfactory epithelium of the nasal cavity that is sensitive to odorants. Cilia at the base of the olfactory receptors contain receptor sites for odorants. The receptors themselves collectively form the olfactory nerve, which synapses with cells in the olfactory bulb. Also called olfactory sense organ. See olfactory stimulation.

olfactory reference syndrome

olfactory reference syndrome a cluster of symptoms that include an excessive and irrational fear that one is emitting an unpleasant or offensive body odor, typically accompanied by frequent compulsions (e.g., excessive bathing or use of deodorant), and that cause significant distress or impairment in social, occupational, or other important areas of functioning. Olfactory reference syndrome is considered by many to be a form of either body dysmorphic disorder or obsessive-compulsive disorder. Also called autodysomophobia; bromosis. See also taijin kyofusho.

olfactory sense organ

olfactory sense organ see olfactory receptor.

olfactory stimulation

olfactory stimulation the excitation of the cilia of olfactory receptors in the nasal cavity by inhaled odorants, which are absorbed into nasal mucus. There is little agreement on the precise mechanism involved in this excitation.

olfactory sulcus

olfactory sulcus a groove on the surface of each cerebral hemisphere, on the inferior (lower) side of the frontal lobe.

olfactory system

olfactory system the primary structures and processes involved in an organism’s detection of and responses to odorants. The olfactory system includes several million olfactory receptors in the nasal cavity, the olfactory epithelium and vomeronasal system, olfactory transduction, neural impulses and pathways (see olfactory nerve), and associated brain areas and their functions.

olfactory tract

olfactory tract a band of nerve fibers that originates in the olfactory bulb and extends backward along the bottom side of the frontal lobe of the brain to a point called the olfactory trigone, at which point the tract divides into three strands leading to the medial and lateral olfactory gyri and the olfactory tubercle. See also lateral olfactory tract.

olfactory transduction

olfactory transduction the sequence of events by which the chemical molecules of an odorant are detected by olfactory receptors and transformed by the olfactory nerve into electrical signals perceived as smells by the olfactory bulb. As in other sense systems, the conjoint activation of many receptors and the modulating effects of second messengers play important roles in olfactory transduction.

olfactory tubercle

olfactory tubercle a small oval elevation near the base of the olfactory tract that contains auxiliary olfactory nerve fibers and cells. The olfactory tubercle is particularly prominent in nonhuman animals that depend on a sense of smell to survive.

oligarchy

oligarchy n. 1. rule by a small elite group. 2. those who constitute such a group. —oligarchic adj.

oligo- (olig-)

Sorry, "oligo-olig" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

oligodendrocyte

oligodendrocyte n. a type of nonneuronal central nervous system cell (glia) that forms myelin sheaths around axons. Also called oligodendroglia.

oligodendroglioma

oligodendroglioma n. see glioma.

oligohydramnios

oligohydramnios n. a deficiency of amniotic fluid, which can result in mechanical interference with fetal movements and possible congenital defects, such as clubfoot, torticollis, muscular dystrophy, or brain damage.

oligospermia

oligospermia n. an abnormally low content of spermatozoa in a sample of semen. Oligospermia is one of several factors responsible for male infertility. The usually accepted minimum level of sperm needed to ensure fertility is 20 million per ml.

olisbos

olisbos n. see dildo.

olivary nucleus

olivary nucleus an olive-shaped mass of gray matter in the medulla oblongata, comprised of two sets of nuclei: the inferior olivary complex (or inferior olivary nucleus or inferior olive), which lies on the ventral part of the medulla oblongata and is believed to be involved in motor control; and the superior olivary complex (or superior olivary nucleus or superior olive), which lies in the pons just above the inferior olivary complex and plays a significant role in the perception and localization of sound. Also called olivary body; olivary complex.

Oliver–McFarlane syndrome

Oliver–McFarlane syndrome see trichomegaly-retinal degeneration syndrome. [first described in 1965 by ophthalmologists Glen L. Oliver (d. 2002) and D. C. McFarlane]

olivocochlear bundle

olivocochlear bundle a tract of centrifugal or efferent fibers extending from the superior olivary complex through the descending neural pathways to the cochlear hair cells.

olivopontocerebellar atrophy

olivopontocerebellar atrophy a slowly progressive neurological disorder characterized by degeneration of neurons in the pons, cerebellum, and olivary nucleus. Symptoms are highly variable across individuals but typically include ataxia, difficulties with balance and walking, tremors, and dysarthria. In many cases, onset is in middle adulthood and death occurs within 10 to 20 years.

ololiuqui

ololiuqui n. the seed of a Latin American vine, Rivea corymbosa, which contains substances chemically related to LSD but less potent. Ololiuqui was first described in the reports of the 16th-century Spanish physician Francisco Hernández while studying the indigenous peoples of Mexico, who used it for both medicinal and religious purposes.

OLS

OLS abbreviation for ordinary least squares. See least squares regression.

OLSAT

OLSAT acronym for Otis–Lennon School Ability Test.

ombudsman

ombudsman n. a person or program responsible for investigating consumer complaints and grievances and acting as a consumer advocate in resolving problems (e.g., in a healthcare facility).

omega squared

omega squared (symbol: ω2) a measure of the strength of association based on the proportion of variance of one measure predictable from variance in other measures. In analysis of variance, it indicates how much variation in a dependent variable can be explained by variation in one or more independent variables.

omen

omen n. an event that is regarded, rationally or not, as a portent of future good or ill fortune. The study of supernatural omens was known as augury.

omission training

omission training see differential reinforcement of other behavior.

omitted variable bias

omitted variable bias the situation in which values calculated from a statistical model systematically overestimate or underestimate a degree of relationship or other quantity of interest because an important variable has been left out of the model. For example, a researcher could hypothesize a linear regression equation in which stressful life events and lack of social support predict depression. If coping skills also are highly relevant to predicting depression, the researcher’s failure to include that element in his or her conceptualization would create an omitted variable bias. The exclusion of important variables from models may constrain the validity of study findings. See also biased estimator.

omnibus test

omnibus test 1. any statistical test of significance in which more than two conditions are compared simultaneously or in which there are two or more independent variables. The analysis of variance is an example. For instance, assume a researcher collects data from an experimental design having two independent variables, each of which has three different levels or conditions. He or she could conduct an analysis of variance to concurrently examine the mean values for all levels of each of the variables (and their combinations) in order to determine whether there are any significant differences among them. 2. a type of exam that simultaneously measures several different abilities. For example, a mathematics omnibus test may include items assessing numeracy, algebraic skills, geometric proficiency, and trigonometric competency.

omnipotence

omnipotence n. in psychology, the delusion that one can personally direct, or control, reality outside of the self by thought or wish alone. Psychology generally considers feelings of omnipotence to fall anywhere between neurosis, in its milder forms, and psychosis, when the delusion is expressed as alienation from or outright denial of reality. In psychoanalytic theory, the main emphasis is on the infant’s feeling that he or she is all-powerful, which is thought to arise (a) out of satisfaction of the child’s slightest gesture; (b) out of increasing cognitive and physical abilities; and (c) as a reaction formation to feelings of helplessness and anxiety. See also megalomania; primary narcissism. —omnipotent adj.

omnipotent therapist

omnipotent therapist see prestige suggestion.

on cells (ON cells)

Sorry, "on-cells-on-cells" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

on response (ON response)

Sorry, "on-response-on-response" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

on-center bipolar cell

on-center bipolar cell a retinal bipolar cell that is excited by light in the center of its receptive field but is inhibited by light in the surround. See also on response. Compare off-center bipolar cell.

on-center ganglion cell

on-center ganglion cell a retinal ganglion cell that is excited by light in the center of its receptive field but is inhibited by light in the surround. See also on response. Compare off-center ganglion cell.

on-center/off-surround

Sorry, "on-center-off-surround" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

on-the-job training

on-the-job training training provided in the workplace during regular working hours for the purpose of developing or enhancing the knowledge, skills, and abilities of employees. Compare off-the-job training. See also vestibule training.

on-time life events

on-time life events events that occur at the typical or expected point in the lifespan for members of a given population. Examples are marriage in young adulthood and retirement in later adulthood. Compare off-time life events.

on–off cell

on–off cell a type of neuron in the visual system, particularly the retina, that depolarizes when the retina is stimulated with either light onset or light offset.

onanism

onanism n. coitus interruptus or masturbation. Onanism is named for the biblical character Onan, who “went to his brother’s wife and spilled it [his seed] on the ground” (Genesis 38:9).

oncology

oncology n. the study and treatment of benign and malignant tumors (see neoplasm). This branch of medicine and of behavioral or population sciences deals with cancer and is subdivided into medical, radiation, surgical, behavioral, and epidemiological subtypes. —oncologist n.

ondansetron

ondansetron n. a serotonin antagonist at the 5-HT3 serotonin receptor that is used for the prevention and treatment of nausea resulting from chemotherapy or anesthesia. When combined with appropriate behavior therapy, it may also be an effective adjunctive agent in managing certain types of alcoholism, although it is not officially approved by the U.S. Food and Drug Administration for such treatment. U.S. trade name: Zofran.

one-factor analysis of variance

one-factor analysis of variance see one-way analysis of variance.

one-group pretest–posttest design

one-group pretest–posttest design a variation of the pretest–posttest design in which only a single set of participants is measured on a dependent variable of interest, exposed to a treatment or intervention, and then measured again to determine the change or difference between the initial (pre-) and second (post-) measurement. The lack of a control group in this type of research design makes it difficult to attribute gains in the posttest score to the intervention, as other elements (e.g., participant maturation) may have contributed to any change observed. Also called one-group pre–post design.

one-parameter model

one-parameter model see Rasch model.

one-person psychology

one-person psychology in relational psychoanalysis, a term used to characterize classical psychoanalysis as a perspective that focuses on the patient’s intrapsychic life and assumes that the analyst’s or therapist’s role is largely as an objective observer of manifestations of the patient’s dynamics. Compare two-person psychology.

one-sample t test

one-sample t test see single-sample t test.

one-sample test

one-sample test see single-sample test.

one-shot case study

one-shot case study a research design in which a single group is observed on a single occasion after experiencing some event, treatment, or intervention. Because there is no control group against which to make comparisons, it is a weak design; any changes noted are merely presumed to have been caused by the event.

one-sided message

one-sided message a message containing arguments that solely advocate one side of an issue. It is contrasted with a two-sided message, which predominantly advocates one side but also acknowledges—and sometimes refutes—the other side of an issue. One-sided messages tend to be most effective when recipients are unlikely to generate arguments on the other side of the issue. Two-sided messages are most successful when recipients are likely to generate opposing arguments.

one-tailed hypothesis

one-tailed hypothesis see directional hypothesis.

one-tailed test

one-tailed test see directional test.

one-trial learning

one-trial learning the mastery of a skill after the first training trial.

one-way analysis of covariance

one-way analysis of covariance an analysis of covariance in which there is a single independent variable and one or more covariates whose potential influence needs to be accounted for statistically. For example, assume a researcher is evaluating how three types of instructional methods (three levels of the independent variable) affect scores on an academic achievement test (the dependent variable). If the researcher believes general intelligence, gender, and other unmeasured factors could also affect scores, he or she might use a one-way analysis of covariance to control for such covariates when assessing the experimental data.

one-way analysis of variance

one-way analysis of variance an analysis of variance that evaluates the influence of different levels or conditions of a single independent variable upon a dependent variable. The mean values of two or more samples are examined in order to determine the probability that they have been drawn from the same population. Also called one-factor analysis of variance.

one-way design

one-way design an experimental design in which a single independent variable is manipulated to observe its influence on a dependent variable. For example, a researcher could use a one-way design to examine the effect of different amounts of daily exercise (e.g., 0 minutes, 30 minutes, 60 minutes) on mood. Also called single-factor design.

one-word stage

one-word stage the developmental period, between approximately 10 and 18 months, when children use one word at a time when speaking. Complex ideas are sometimes expressed with a single word, accompanied by gestures and emphasis. For example, depending on the context and how the word is spoken, milk may mean That is milk, I want more milk, or I spilled the milk. Also called holophrastic stage. See holophrase.

oneirism

oneirism n. a dreamlike state in a condition of wakefulness. —oneiric adj.

oneiro- (oneir-)

Sorry, "oneiro-oneir" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

oneirodynia

oneirodynia n. a form of dreaming characterized by nightmares or unpleasant dreams.

oneiromancy

oneiromancy n. the art or practice of divining the future from dreams. See divination. See also clairvoyant dream; premonitory dream.

oneirophrenia

oneirophrenia n. a dreamlike, hallucinatory state resembling schizophrenia in certain symptoms, such as disturbances of emotion and associations, but distinguished from schizophrenia by disturbances of the senses and clouding of consciousness. It is associated with prolonged sleep deprivation, sensory deprivation, or drug use, but it is not widely considered a distinct clinical entity. [first described in the 1950s by Hungarian-born U.S. psychiatrist Ladislas von Meduna (1896–1964)]

oniomania

oniomania n. compulsive shopping, or an uncontrollable impulse to spend money and to buy without regard to need or use.

online group

online group a group whose members communicate with one another solely or primarily through computer-based information technologies rather than through face-to-face interactions. Compare offline group.

online self-help group

online self-help group a group of individuals who communicate over the Internet on a regular basis to help one another cope with a shared life problem. Online groups overcome some of the barriers to participation in traditional self-help groups, including lack of local group availability and transportation constraints.

online social network

online social network a set of interconnected individuals who interact using computer-based technologies rather than through face-to-face interactions. An example is a community of Internet video gamers, the members of which each have defined roles and relationships.

online therapy

online therapy see e-therapy.

onomatopoeia

onomatopoeia n. the formation of a word whose sound replicates to a recognizable degree the sound of the thing or action that it represents, such as hiss, smack, or cuckoo. See also iconic symbol. —onomatopoeic adj.

onset insomnia

onset insomnia see initial insomnia.

onset of action

onset of action the point at which the activity of a drug is apparent, generally measured in terms of the time elapsed between administration and the appearance of its pharmacological effects.

ontoanalysis

ontoanalysis n. a form of existential analysis that probes the ultimate nature of being.

ontogenetic fallacy

ontogenetic fallacy the false assumption that anything that looks like a common pattern of change with age is a basic, normative process of aging. An example is the assumption that because disability is often seen in the elderly it is a natural, universally experienced outcome of the aging process. [proposed by 21st-century U.S. sociologist Dale Dannefer]

ontogenetic psychology

ontogenetic psychology the study of the psychological aspects of the biological development of the individual (see ontogeny) as opposed to that of the species (see phylogeny). Also called ontogenic psychology.

ontogeny

ontogeny n. the biological origin and development of an individual organism from fertilization of the egg cell until death. Also called ontogenesis. Compare phylogeny. See also recapitulation theory. —ontogenetic adj.

ontogeny of conscious experience

ontogeny of conscious experience the developmental emergence of consciousness in an organism. See infant consciousness.

ontological confrontation

ontological confrontation the keen and immediate awareness of personal mortality that can occur when an individual’s usual defenses against death awareness are pierced by circumstances or evoked memories. See also death anxiety; terror management theory.

ontology

ontology n. the branch of philosophy that deals with the question of existence itself. From some philosophical perspectives, ontology is synonymous with metaphysics, in that both ask fundamental questions about what reality is. However, from the perspective of contemporary existentialism and hermeneutics, ontology implies a concern with the meaning of existence that is largely lacking in traditional metaphysics. Whereas metaphysics asks “What is there?” or “What is fundamental?,” the question of ontology is often posed as “What does it mean to ‘be’ at all?” For example, to say that Smith is a professor is to rely on a very different sense of the verb be than is present in a statement that Smith is hungry. Likewise, Smith is not a professor in the same way that a painting is beautiful. Contemporary approaches to ontology often take their analytical point of departure from the work of German philosopher Martin Heidegger (1889–1976). In this tradition, psychology is the pursuit of an adequate understanding of the ontology of human beings. It asks, or ought to ask, “What does it mean to be a human being?” See being-in-the-world; Dasein; existential phenomenology. —ontological adj.

oocyte

oocyte n. a cell in the ovary from which an ovum (egg cell) develops in the process of oogenesis.

oogenesis

oogenesis n. the process by which germ cells divide and differentiate to produce female gametes (ova). In human females, primary oocytes are formed in the ovary during embryonic development by the proliferation and differentiation of precursor cells called oogonia (sing. oogonium). The primary oocytes enter into the first division of meiosis but then remain suspended at this stage of cell division until puberty. Thereafter, roughly once a month until menopause, one primary oocyte resumes meiosis and completes the first meiotic division to produce two unequally sized daughter cells: The larger one is the secondary oocyte, and the smaller is a polar body. Following ovulation, the secondary oocyte undergoes the second meiotic division to produce an ovum and another polar body. The first polar body might also divide to produce two tiny cells, resulting in three polar bodies, which are normally nonfunctional and degenerate.

oophorectomy

oophorectomy n. see ovariectomy.

opaque

opaque adj. unable to transmit light: neither transparent nor translucent.

open adoption

open adoption see adoption.

open call system

open call system a system of vocal communication in which new vocalizations can be added throughout life. Whereas many songbirds rarely show change in song structure after the end of a critical period, other birds, including parrots, starlings, mynahs, and mockingbirds, can acquire new calls and songs throughout their lives. Few mammals have an open call system, but some dolphins and whales show evidence of acquiring new calls throughout life. Compare closed call system.

open class society

open class society a society that permits or encourages social mobility. Compare fixed class society.

open design

open design see open-classroom design; open-office design.

open economy

open economy an experimental design used in operant-conditioning experiments in which an organism’s intake of food or water includes not only that provided during experimental sessions but also that provided in supplemental amounts independent of behavior in the home cage. This ensures that a particular level of body weight, or some other measure of deprivation, is maintained. Compare closed economy.

open group

open group a group to which new members may be admitted. In counseling or therapy, the term refers to a group that allows new members during the course of therapy. Also called continuous group. Compare closed group.

open head injury

open head injury a head injury, such as a gunshot wound, in which the skull is penetrated or broken open. Also called penetrating head injury. Compare closed head injury.

open hospital

open hospital a psychiatric hospital without locked doors or physical restraints. Also called open-door hospital.

open marriage

open marriage 1. a marriage in which both partners allow and encourage each other to grow and change over the years. Compare closed marriage. 2. a marital arrangement (formal or common-law) in which the partners permit each other to have sexual relations with other people. See also nontraditional marriage.

open question

open question 1. in a test or survey, an item that does not come with any multiple-choice options for the respondent. Compare fixed-alternative question. 2. in an interview, a question that encourages the respondent to answer freely in his or her own words, providing as much or as little detail as desired. For example, a candidate in a job interview may be asked the open question, “How would you describe yourself?”

open shop

open shop a work arrangement in which union membership is voluntary and is not required as a condition of employment. Compare closed shop. See also agency shop; union shop.

open skill

open skill any motor skill that is performed under varying conditions on each occasion, as in making a jump shot in a game of basketball. Compare closed skill.

open society

open society a form of social organization characterized by respect for human rights, freedom to voice dissenting opinions, elective government, and the rule of law. Essential to this concept is an awareness of the imperfect nature of government and the need for constant critical evaluation of social policy so that it evolves with changing circumstances or new insights. A closed society, by contrast, is one characterized by inflexible social structures and a fixed ideology that cannot accept criticism or tolerate difference. See also democracy. [described by French philosopher Henri Bergson (1859–1941) and later developed by Austrian-born British philosopher Karl Popper (1902–1994)]

open study

open study a research project in which new participants can be added after the project has begun.

open system

open system 1. a system with permeable boundaries that permit exchange of information or materials with the environment. 2. a biological system in which growth can occur without conforming to laws of thermodynamics or a demonstrated constancy of energy relations. Compare closed system.

open system theory

open system theory a theoretical perspective that views the organization as open to influence from the environment. The organization is viewed as transforming human and physical resources from the environment into goods and services, which are then returned to the environment.

open ward

open ward a hospital ward or unit in which the doors are not locked.

open word

open word see pivot grammar.

open-class words

open-class words in a language, a category of words that readily admits new members, such as those arising through borrowing, word formation, or technological innovation. In practice, this category is virtually identical with the category of content words because it usually excludes grammatical function words. Compare closed-class words.

open-classroom design

open-classroom design a design of classroom that provides a study environment based on results of behavior mapping. The open physical construction of the classroom, occasionally without walls, creates an environment suitable for less formal learning styles. In addition, an instructor may opt to arrange desks in a circular formation to facilitate discussion or in groupings of four or six for small group work, as opposed to the traditional classroom design in which rows of desks are arranged in parallel lines.

open-classroom method

open-classroom method an approach to teaching and learning that emphasizes the student’s right to make decisions and that views the teacher as a facilitator of learning rather than a transmitter of knowledge. The open-classroom method may include grouping of students across grades, independent study, individualized rates of progression, open-plan schools without interior walls, or unstructured time and curricula.

open-door hospital

open-door hospital see open hospital.

open-ended interview

open-ended interview an interview in which the interviewee is asked questions that cannot be answered with a simple yes or no. For example, a human resources staff member interviewing a candidate for employment might ask, “What were the major responsibilities of your most recent job?” Open-ended interviews encourage interviewees to talk freely and extensively, thus providing information that might not be obtained otherwise. The general questions and their order may be planned in advance (see standardized interview), or a single initial question can be planned and the subsequent discussion allowed to pursue various areas of interest as they arise (see unstructured interview).

open-field chamber

open-field chamber an enclosed space in which research animals can move freely while their ambulatory and defecatory behavior is observed and measured. See also animal open-field behavior.

open-field test

open-field test an experimental technique for measuring (quantifying) behaviors and physiological reactions (e.g., those indicative of anxiety) in rats and other small animals. The animal is placed in a space divided into squares so that the researcher may observe the number of squares the animal traverses in a specified time period.

open-label study

open-label study a clinical trial in which both the researcher and the participant know the treatment the participant is receiving.

open-loop system

open-loop system 1. a system that requires constant external inputs, as opposed to one that continually recycles the initial input. 2. a system that will continue to follow a particular set of commands, irrespective of adverse results or altered conditions, because it has no capacity to monitor or regulate itself through feedback. An example is a garden sprinkler system that is set to come on at specific times, even if it is raining. Compare closed-loop system.

open-office design

open-office design a type of office design consisting of a large area with very few partitions between work spaces. A premium is placed on flexibility and visual accessibility, which are believed to support innovation and communication. Evidence indicates mixed results, with positive responses for team activities but problems with distraction and lack of privacy. There also appear to be individual differences in tolerance for open-plan spaces. See also landscaped office.

opening technique

opening technique the means by which a therapist establishes initial rapport and trust at the beginning of a professional relationship with a client in therapy or at the beginning of each session in individual or family therapy. Also called opening moves.

openmindedness

openmindedness n. a personality trait reflecting a relative lack of dogmatism. Compare closedmindedness. —openminded adj.

openness to experience

openness to experience a dimension of the Big Five personality model and the five-factor personality model that refers to individual differences in the tendency to be open to new aesthetic, cultural, or intellectual experiences.

operandum

operandum n. in operant conditioning, a device that a nonhuman animal operates or manipulates to produce automatic recording of a response. For example, in a simple conditioning experiment for a rat, a lever that the rat can press would be the operandum. See also manipulandum.

operant

operant n. a class of responses that produces a common effect on the environment. An operant is defined by its effect rather than by the particular type of behavior producing that effect. A distinction may be made between the behavior required to achieve the effect and those alternative forms of behavior that constitute the class and may also occur. In the former, the class might include all forms of behavior that result in a lever being moved 4 mm downward (see descriptive operant). In the latter case, the class includes all forms of behavior that become more probable; for example, a rat’s two-handed lever presses might increase in probability, but one-handed presses might not (see functional operant). Compare respondent.

operant behavior

operant behavior behavior that produces an effect on the environment and whose likelihood of recurrence is influenced by consequences (see operant). Operant behavior is nearly synonymous with voluntary behavior.

operant chamber

operant chamber an apparatus for the laboratory study of operant behavior. It typically consists of a small enclosure and is equipped so that all stimuli are presented, and all responses are detected and recorded, automatically. See operant conditioning chamber.

operant conditioning

operant conditioning the process in which behavioral change (i.e., learning) occurs as a function of the consequences of behavior. Examples are teaching a dog to do tricks and rewarding behavioral change in a misbehaving child (see behavior therapy). The term is essentially equivalent to instrumental conditioning. Also called operant learning. See behavior modification; shaping. [first described by B. F. Skinner]

operant conditioning chamber

operant conditioning chamber an apparatus used to study free-operant behavior. Generally, it provides a relatively small and austere environment that blocks out extraneous stimuli. Included in the environment are devices that can present stimuli (e.g., reinforcers) and measure free-operant responses. For example, the apparatus for a rat might consist of a 25-cm3 space containing a food tray, which can be filled by an automatic feeder located outside the space, and a small lever that the rat may press to release food from the feeder. Measurement of behavior and presentation of stimuli in the apparatus are usually automatic. The apparatus was initially developed in the 1930s by B. F. Skinner. It later became known colloquially as the Skinner box, although Skinner himself disliked this term.

operant conditioning therapy

operant conditioning therapy a therapeutic approach that relies on the use of antecedents, behaviors, and consequences. For example, reinforcement through rewards may be used to improve behaviors in everyday situations.

operant learning

operant learning see operant conditioning.

operant level

operant level a baseline probability or frequency of behavior that occurs naturally, before reinforcement is arranged, as in the amount of lever pressing by a rat before any food reward or other reinforcer is introduced.

operant paradigm

operant paradigm 1. the experimental arrangement of a contingency between a response and a consequence, such as reinforcement. 2. more generally, the assumption that much human behavior is controlled by its consequences.

operant response

operant response a single instance from an operant class. For example, if lever pressing has been conditioned, each single lever press is an operant response.

operation

operation n. 1. a type of cognitive scheme that is mental (i.e., requires symbols), derives from action, exists in an organized system in which it is integrated with all other operations (structures of the whole), and follows a set of logical rules, most importantly that of reversibility. [postulated by Jean Piaget] 2. a surgical procedure.

operation span (OSpan)

Sorry, "operation-span-ospan" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

operational analysis

operational analysis analysis of the decision-making processes underlying the accomplishment of complex tasks. Generally, the tasks involve the tracing of inputs through a process and the tracking of outputs. The analysis usually involves mathematical modeling and statistical techniques and aims at maximizing the effectiveness of the process.

operational definition

operational definition a description of something in terms of the operations (procedures, actions, or processes) by which it could be observed and measured. For example, the operational definition of anxiety could be in terms of a test score, withdrawal from a situation, or activation of the sympathetic nervous system. The process of creating an operational definition is known as operationalization.

operational research

operational research see operations research.

operational sex ratio

operational sex ratio the relative number of males and females available at the time when reproduction is possible. In nonhuman mammals with internal gestation and lactation, there are often fewer females receptive to copulation than available males, creating an operational sex-ratio bias toward males, even though adults of both sexes may be present in equal numbers. In polygynous species (see polygyny), there might be more receptive females than available males, creating an operational sex-ratio bias toward females.

operational thought

operational thought in Piagetian theory, the type of thought characteristic of the last two stages of a child’s cognitive development, the concrete operational stage and formal operational stage.

operationalism

operationalism n. the position that the meaning of a scientific concept depends upon the procedures used to establish it, so that each concept can be defined by a single observable and measurable operation. An example is defining an emotional disorder as a particular score on a diagnostic test. This approach was mainly associated with radical behaviorism. Also called operationism.

operationism

operationism n. see operationalism.

operationist view of consciousness

operationist view of consciousness the notion that conscious experiences may be reduced to publicly observable events, such as discriminative responses. [championed by Stanley Smith Stevens and Edwin G. Boring]

operations research

operations research the application of advanced analytical methods—such as mathematical modeling, optimization, and computer simulation—to the study of complex situations so as to obtain a comprehensive understanding that allows for accurate predictions of outcomes and estimates of risk and enables more rational, effective decision making. It is used particularly in management science and business contexts. Also called operational research.

operative knowledge

operative knowledge knowledge acquired in the process of performing operations, thought to be more basic and more predictive of later intellectual functioning than figurative knowledge (e.g., factual knowledge). [postulated by Jean Piaget]

operators

operators pl. n. the mental processes involved in comprehending the effect of different manipulations on quantity, as in knowing that adding an orange to a bowl of oranges changes the number, whereas rearranging the oranges does not. Compare estimators. [first used in this sense by U.S. statistician Andrew Gelman]

ophidiophilia

ophidiophilia n. an abnormal fascination with snakes.

ophidiophobia

ophidiophobia n. see snake phobia.

ophthalmia

ophthalmia n. severe inflammation of the eye that may affect either the conjunctiva or deeper structures. Mucous (or catarrhal) ophthalmia is a form of conjunctivitis with a purulent secretion; electric ophthalmia is produced by exposure to the light of an electric welding torch; neuroparalytic ophthalmia is a corneal inflammation with possible ulceration associated with lesions of the trigeminal nerve. See also trachoma.

ophthalmic nerve

ophthalmic nerve a division of the trigeminal nerve that mediates sensation of the orbit of the eye, the anterior part of the nasal cavity, and the skin of the nose and forehead.

ophthalmology

ophthalmology n. the medical specialty concerned with the study of the eye and the diagnosis and treatment of eye disease. A physician who specializes in ophthalmology is called an ophthalmologist. Compare optometry.

ophthalmometer

ophthalmometer n. see keratometer.

ophthalmoplegia

ophthalmoplegia n. paralysis of one or more of the internal or external muscles of the eye (see oculomotor palsy). See also progressive supranuclear palsy.

ophthalmoplegia externa

ophthalmoplegia externa see Ballet’s disease.

ophthalmoscope

ophthalmoscope n. a hand-held device used to examine the structures of the eye, especially the fundus (back). This examination may be direct, with the eye at close range so as to observe an erect image, or indirect, by use of a lens that produces an inverted image of the fundus. Compare retinoscope.

opiate

opiate n. any of a variety of natural and semisynthetic compounds derived from opium. They include the alkaloids morphine and codeine and their derivatives (e.g., heroin [diacetylmorphine]). Opiates, together with synthetic compounds having the pharmacological properties of opiates, are known as opioids.

opinion

opinion n. an attitude, belief, or judgment.

opinion leader

opinion leader an individual to whom others turn for advice or on whom others model their behavior. To be effective, the opinion leader needs to have social ties with other members of the group.

opinion survey

opinion survey a technique in which a large number of people are polled to determine their collective views, beliefs, or attitudes about a particular topic of interest. Information so obtained often is extrapolated to a broader population with a given margin of error. For example, during an election year one might conduct an opinion survey of preferences for potential U.S. presidential candidates in different states. Also called opinion poll.

opinion testimony

opinion testimony court evidence that includes inferences or conclusions rather than actual facts observed or experienced. Opinion testimony is usually allowed only from expert witnesses, because they have specialized knowledge that will aid the judge or jury in reaching a decision. See ultimate opinion testimony. See also learned treatise exception.

opinionnaire

opinionnaire n. a type of measure for assessing the attitudes or beliefs of an individual about particular topics. It comprises a list of various statements that the respondent is asked to endorse or reject.

opioid

opioid n. any of a group of compounds that include the naturally occurring opiates (e.g., morphine) and their semisynthetic derivatives (e.g., heroin); the synthetic opioid agonists (e.g., meperidine, methadone), opioid antagonists (e.g., naloxone, naltrexone), and mixed agonist–antagonists (e.g., butorphanol); and the endogenous opioids. The effects of opioids include analgesia, drowsiness, euphoria or other mood changes, respiratory depression, and reduced gastrointestinal motility. Opioids are used clinically as pain relievers, anesthetics, cough suppressants, and antidiarrheal drugs, and many are subject to abuse and dependence.

opioid abuse

opioid abuse in DSM–IV–TR, a pattern of opioid use marked by recurrent significant adverse consequences related to the repeated ingestion of an opioid such as morphine, heroin, or substances with morphinelike effects (e.g., codeine, oxycodone). This diagnosis is preempted by the diagnosis of opioid dependence: If the criteria for opioid abuse and opioid dependence are both met, only the latter diagnosis is given. In DSM–5, however, both have been subsumed into opioid use disorder and are no longer considered distinct diagnoses. See also substance abuse.

opioid agonist

opioid agonist any drug with enhancing effects at opioid receptors in the central nervous system. Opioid agonists may be complete (pure) or partial agonists. Morphine is a pure opioid agonist; other examples include codeine, heroin, methadone, meperidine, and LAAM. Opioid partial agonists (e.g., buprenorphine) have lower levels of activity than complete opioid agonists at the same receptors and consequently have less analgesic activity. Also called narcotic agonist.

opioid analgesic

opioid analgesic any opioid used clinically to reduce both the sensation of pain and the emotional response to pain. This analgesia results from agonist activity at the mu opioid receptor. Codeine, dihydrocodeine, propoxyphene, and hydrocodone are among opioids used for the relief of mild to moderate pain; severe pain is managed with more potent agents, such as morphine, meperidine, oxycodone (U.S. trade name: OxyContin), and levorphanol. Methadone, fentanyl, and buprenorphine are potent analgesics that have additional uses. Side effects associated with opioid analgesics include nausea and vomiting, constipation, sedation, and respiratory depression; many also have the potential for abuse and dependence. Also called narcotic analgesic.

opioid antagonist

opioid antagonist an agent that acts as an antagonist at opioid receptors. Generally, opioid antagonists are synthetic derivatives of morphine that, as a result of structural changes in the molecule, bind to opioid receptors but do not produce the effects of euphoria, respiratory depression, or analgesia that are observed with opioid agonists. Opioid antagonists may be complete (pure) or mixed. Complete antagonists, such as naloxone, naltrexone, nalmefene (U.S. trade name: Revex), and nalorphine, are generally used to reverse the effects of opiate overdose (notably respiratory depression). Mixed agonist–antagonist opioids, such as butorphanol and pentazocine (U.S. trade name: Talwin), were developed in attempts to produce opioid analgesics that did not possess the abuse potential of opioid agonists. Also called narcotic antagonist.

opioid blockade

opioid blockade the inhibition of the euphoric effects of such opioids as heroin by administration of a blocking agent, especially methadone, as maintenance treatment for drug abuse. See methadone maintenance therapy; opioid antagonist.

opioid dependence

opioid dependence in DSM–IV–TR, a pattern of repeated or compulsive use of opioids (e.g., morphine, heroin) despite significant opioid-related behavioral, physiological, and psychosocial problems and/or tolerance or characteristic withdrawal symptoms if use is suspended (see opioid withdrawal). In DSM–5, opioid dependence and opioid abuse have been subsumed into opioid use disorder and are no longer considered distinct diagnoses. Also called narcotic dependence. See also substance dependence.

opioid intoxication

opioid intoxication in DSM–IV–TR and DSM–5, a reversible syndrome due to the recent ingestion of an opioid (e.g., morphine, heroin). It includes clinically significant behavioral or psychological changes (e.g., initial euphoria followed by apathy, dysphoria, psychomotor agitation or psychomotor retardation, impaired judgment, and impaired social or occupational functioning), as well as one or more signs of physiological involvement (e.g., pupillary constriction, drowsiness or unconsciousness, slurred speech, respiratory depression).

opioid neurotransmitter

opioid neurotransmitter see endogenous opioid.

opioid receptor

opioid receptor a receptor that binds opioids (including endogenous opioids) and mediates their effects via G proteins. It is generally agreed that there are at least three classes: mu (μ), kappa (κ), and delta (δ) opioid receptors. Opioid receptors are widely distributed in the brain, spinal cord, and periphery, and each type of receptor is differentially distributed. Mu opioid receptors are largely responsible for the analgesic and euphoric effects associated with opioid use. Most exogenously administered opioids bind to mu opioid receptors, which also mediate the respiratory depression, sedation, and reduced gastrointestinal motility associated with opioids. Kappa opioid receptors are localized primarily in the dorsal root ganglia of the spinal cord. Stimulation of these receptors produces more modest analgesia and dysphoric responses and may also be responsible for some of the perceptual and cognitive effects of opioids. Delta opioid receptors may potentiate activity of opioids at the mu opioid receptor site and have a less direct involvement in the production of analgesia. The more recently discovered nociceptin/orphanin FQ (N/OFQ) receptor, included in the opioid receptor family, has not been completely characterized.

opioid system

opioid system the combination of delta, kappa, and mu opioid receptors found in the nervous system and gastrointestinal tract. Strongly involved in the experience of reward and the control of pain, this system is triggered both by opioids produced in the body (see endogenous opioid) and by naturally occurring or synthetic opioids administered exogenously.

opioid use disorder

opioid use disorder in DSM–5, a diagnostic category reflecting disordered use of natural opioids (e.g., morphine), semisynthetic derivatives (e.g., heroin), and synthetic compounds with morphinelike effects (e.g., oxycodone). It combines DSM–IV–TR’s separate abuse and dependence diagnoses for these substances, thereby removing opioid abuse and opioid dependence as distinct entities. Mild, moderate, and severe cases of opioid use disorder are determined according to the number of symptoms that individuals using these substances may present (e.g., craving; drug-seeking behavor; social and other dysfunction caused by opioid use; tolerance; withdrawal, etc.); the number ranges from a minimum of two symptoms for mild cases to more than six for severe.

opioid withdrawal

opioid withdrawal in DSM–IV–TR and DSM–5, a characteristic withdrawal syndrome that develops after cessation of (or reduction in) prolonged, heavy consumption of opioids (e.g., morphine, heroin). Features may include dysphoria or anxiety, nausea or vomiting, muscle aches, dilation of the pupils, piloerection (goose flesh) or sweating, diarrhea, fever, and insomnia. See also substance withdrawal.

Opitz G/BBB syndrome

Sorry, "opitz-g-bbb-syndrome" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

opium

opium n. the dried resin of the unripe seed pods of the opium poppy, Papaver somniferum. Opium contains more than 20 alkaloids (opium alkaloids), the principal one being morphine, which accounts for most of its pharmacological (including addictive) properties; other opium alkaloids include codeine, thebaine, and papaverine. Natural and synthetic derivatives of opium (see opiate; opioid) are eaten, smoked, injected, sniffed, and drunk. Their action, due mainly to their morphine content, is to induce analgesia and euphoria and to produce a deep, dreamless sleep from which the user can be easily aroused.

opponent cell

opponent cell a type of neuron in the visual system that depolarizes when a particular stimulus (e.g., red light) comes on in the center of the neuron’s receptive field and when the “opposite” stimulus (e.g., green light) is extinguished in the surrounding zone of the receptive field. Double-opponent cells depolarize when the red light comes on or the green light is extinguished in the center of the receptive field, whereas the same stimuli produce the opposite effects in the receptive field surround.

opponent process theory of acquired motivation

opponent process theory of acquired motivation a theory that a stimulus or event simultaneously arouses a primary affective state, which may be pleasurable or aversive, and an opponent (opposite) affective state, which serves to reduce the intensity of the primary state: These two states together constitute emotional experience. According to this theory, the opponent state has a long latency, a sluggish course of increase, and a sluggish course of decay after the initiating stimulus is removed, all of which lead to its domination for a period following removal of the stimulus. In contrast to the primary state, it is also strengthened through use and weakened through disuse. This theory sought to account for such diverse acquired motives as drug addiction, love, affection and social attachment, and cravings for sensory and aesthetic experiences. Also called opponent process theory of emotion; opponent process theory of motivation. [originated by Richard L. Solomon]

opponent process theory of color vision

opponent process theory of color vision any one of a class of theories describing color vision on the basis of the activity of mechanisms, which may correspond to cells, that respond to red–green, blue–yellow, or black–white. The Hering theory of color vision, the most highly developed opponent process theory, contrasted with the Young–Helmholtz theory of color vision, which relied on receptors sensitive to specific regions of the spectrum. Although both theories explained many phenomena, both had deficiencies. In the 1950s, Leo Hurvich and Dorothea Jameson suggested that both theories were correct, the Young–Helmholtz model describing a first stage of processing in the visual system whose outputs were then fed into an opponent process. This combined theory is known as the dual process theory of color vision. All three theories were proposed long before physiological studies of retinal neurons had been carried out, yet they were successful in predicting the responses of cells under most conditions.

opportunism

opportunism n. the ability to exploit a variety of resources as they become available in changing environmental conditions or different locations. Some species are able to utilize new food resources rapidly: Kelp gulls introduced in Argentina rapidly expanded in numbers by feeding on refuse from fish factories and subsequently learned to attack and eat flesh from whales calving and nursing young in nearby waters. Other species show no opportunism and cannot exploit novel habitats or food resources.

opportunity class

opportunity class 1. an educational system that provides special-needs students with high-quality academic teaching in a stable, supportive environment with all the elements of a specialized curriculum. 2. an instructional setting that provides guidance and counseling to promote each individual student’s intellectual, social, emotional, and physical growth. 3. a class in the pull-out program for students who do not fit the norm, such as gifted, emotionally challenged, or at-risk students.

opportunity sampling

opportunity sampling see convenience sampling.

opportunity structure

opportunity structure a matrix that relates personal characteristics (e.g., age, disability, race, gender, education, financial status) to the cultural and social opportunities and options that are available to an individual throughout his or her life. According to some psychologists, barred or restricted access to legitimate opportunities for success, due to economic or social disadvantage, leads some individuals to seek success by illegitimate means (an “illegitimate opportunity structure”), such as delinquency or other criminal activity. Also called opportunity matrix.

opposites test

opposites test see antonym test.

oppositional defiant disorder

oppositional defiant disorder in DSM–IV–TR, a behavior disorder of childhood characterized by recurrent disobedient, negativistic, or hostile behavior toward authority figures that is more pronounced than usually seen in children of similar age and lasts for at least 6 months. It is manifest as temper tantrums, active defiance of rules, dawdling, argumentativeness, stubbornness, or being easily annoyed. The defiant behaviors typically do not involve aggression, destruction, theft, or deceit, which distinguishes this disorder from conduct disorder. Oppositional defiant disorder should be distinguished from attention-deficit/hyperactivity disorder, with which it often co-occurs. In DSM–5, the symptom characteristics have largely been retained but are divided into subgroups of mood (e.g., angry, irritable), behavior (e.g., argumentative, defiant), or vindictiveness.

opsin

opsin n. the protein component of visual photopigments. There is one opsin for all rods (rod opsin, or scotopsin), which together with retinal forms the rod photopigment rhodopsin. There are three different cone opsins (photopsins), which convey different peak wavelength sensitivities to each of the three different cone photopigments (see iodopsin).

opt-

Sorry, "opt" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

optic aphasia

optic aphasia inability to name visually presented objects.

optic apraxia

optic apraxia an impairment in the ability to associate tools and other objects with the corresponding action. Individuals with optic apraxia use objects improperly, misselect the objects needed for an intended activity, perform a complex activity (e.g., preparing a cup of tea, dressing) in the wrong order, or do not complete the task at all. In most cases, the temporoparietal or frontal association areas (or both) of the brain’s left hemisphere are affected.

optic array

optic array 1. the visual scene that emerges when patterns of light reaching the eye make available to the observer visual information about the external world. 2. see ambient optic array.

optic ataxia

optic ataxia inability to direct the hand to an object under visual guidance, typically caused by damage to the cortex of the parietal lobe. It is a feature of Bálint’s syndrome. Also called visuomotor ataxia.

optic atrophy

optic atrophy degeneration of fibers of the optic nerve, as occurs in locomotor ataxia, lead or methyl alcohol poisoning, or multiple sclerosis.

optic chiasm

optic chiasm the location at the base of the brain at which the optic nerves from the two eyes meet. In humans, the nerve fibers from the nasal half of each retina cross, so that each hemisphere of the brain receives input from both eyes. This partial crossing is called a partial decussation.

optic disk

optic disk the area of the retina at which the axons of the retinal ganglion cells gather before leaving the retina to form the optic nerve. Because this region contains no photoreceptors, it creates a blind spot in the visual field.

optic flow

optic flow in the retinal image of the eye, the pattern and velocity of observed visual information about the motion of objects in an external scene relative to the motion of the observer. Optical flow patterns play an important role in locomotion; in the orientation, coordination, and balance of the body moving in space, and in the perception of movement in the outside environment. Also called optical flow. See also ecological perception. [first investigated by James J. Gibson]

optic nerve

optic nerve the second cranial nerve, which carries the axons of retinal ganglion cells and extends from the retina to the optic chiasm. Also called cranial nerve II.

optic neuritis

optic neuritis inflammation of the optic nerve, which may lead to sudden, painful loss of vision in one eye.

optic radiations

optic radiations nerve fibers that project from the lateral geniculate nucleus to the visual cortex in the occipital lobe and to the pretectum, a structure in the midbrain important for the reflexive contraction of the pupils in the presence of light. As the optic radiations sweep around the lateral ventricles, they are called Meyer’s loop.

optic tectum

optic tectum the portion of the tectum in the midbrain that serves the visual system. See superior colliculus.

optic tract

optic tract the bundle of optic nerve fibers after the partial decussation of the optic nerves at the optic chiasm. The major targets of the optic tract are the lateral geniculate nucleus in the thalamus and the superior colliculus in the midbrain.

optical axis

optical axis a theoretical line that passes through the center of an optical system. In the case of the eye, it passes through both the cornea and the lens.

optical defect

optical defect any condition of the eye that prevents light rays from focusing properly on the retina. See refractive error.

optical flow pattern

optical flow pattern see optic flow.

optical illusion

optical illusion a false visual image produced by either physical or psychological factors. See illusion.

optical projection

optical projection 1. the formation of a visual image by means of a slide projector or similar device. 2. the localization of objects in space that correspond to the image on the retina.

optical scanner

optical scanner 1. a device for examining small or isolated areas by means of reflected or projected light. It is used in various chemical and physiological studies, for example, to determine the density of red blood cells in a blood sample and to identify molecules of a sugar or amino acid. 2. a device for converting photographs, print, and other visual material into digital representations that can be stored in a computer and treated as data (for transmission, modification, or printing).

optician

optician n. see optometry.

optics

optics n. the study of the physics of light, including its relations to the mechanisms of vision.

optimal adjustment

optimal adjustment the ideal degree and quality of coping with life or with a specific stressful event.

optimal apparent motion

optimal apparent motion the perception of movement that occurs when the conditions used to produce apparent movement are ideal. For example, in the production of beta movement, the timing and spacing of individual stationary stimuli can be manipulated to produce optimal apparent motion.

optimal arousal theory

optimal arousal theory see principle of optimal stimulation.

optimal design

optimal design an approach to experimental design in which the conditions to be studied and the assignment of participants to those conditions are determined so as to best fulfill particular statistical criteria.

optimal distinctiveness theory

optimal distinctiveness theory a conceptual analysis that assumes individuals strive to maintain a balance between three basic needs: the need to be assimilated by groups to which they belong, the need to be connected to friends and loved ones, and the need for autonomy and differentiation. [proposed in 1991 by U.S. social psychologist Marilynn Brewer (1942– )]

optimal foraging theory

optimal foraging theory a theory of foraging behavior arguing that natural selection has created optimal strategies for food selection (based on nutritional value and costs of locating, capturing, and processing food) and for deciding when to leave a particular patch to seek resources elsewhere. Many aspects of optimal foraging theory have been studied empirically using operant conditioning with different schedules of reinforcement and reward quality. See also marginal value theorem.

optimal functioning

optimal functioning the highest possible level of functioning, especially in relationships, work, education, and subjective well-being.

optimal level

optimal level the maximum (highest) level of complexity of a skill that an individual can control, which can be attained only in the most supportive environment. It has been suggested that when acquiring a skill an individual moves from the optimal level, at which the skill can be performed with assistance from others, to the functional level, at which the skill can be performed independently but possibly at a lower than optimal level. See skill theory. [proposed by U.S. psychologist Kurt W. Fischer (1943– ]

optimal outbreeding

optimal outbreeding see inbreeding avoidance.

optimal scaling

optimal scaling see dual scaling.

optimal stimulation principle

optimal stimulation principle see principle of optimal stimulation.

optimism

optimism n. hopefulness: the attitude that good things will happen and that people’s wishes or aims will ultimately be fulfilled. Optimists are people who anticipate positive outcomes, whether serendipitously or through perseverance and effort, and who are confident of attaining desired goals. Most individuals lie somewhere on the spectrum between the two polar opposites of pure optimism and pure pessimism but tend to demonstrate sometimes strong, relatively stable or situational tendencies in one direction or the other. See also expectancy-value model. —optimistic adj.

optimization

optimization n. a statistical process in which algorithms are applied to data from a sample so as to obtain the best estimate of a value for a parameter of interest in the broader population.

optimize

optimize vb. to create conditions that produce the best possible (optimum) outcome of something in the face of existing constraints.

opto- (opt-)

Sorry, "opto-opt" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

optogram

optogram n. the physical image produced on the retina by the bleaching of rhodopsin by a visual stimulus (see pigment bleaching). In the 19th century, optograms were obtained by rapidly removing the retina of experimental animals after they had viewed a bright stationary stimulus and, in several instances, by examining the retinas of human prisoners immediately after execution.

optokinetic effect

optokinetic effect 1. any of a broad class of perceptual and motor responses to movement of the eyes. 2. the movements of the eyes themselves in response to various moving stimuli.

optokinetic reflex (OKR)

Sorry, "optokinetic-reflex-okr" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

optometry

optometry n. the clinical field concerned primarily with the optics of the eye and the devices and procedures that can correct optical defects. Optometrists can prescribe corrective lenses and exercises but are generally prohibited from prescribing drugs or performing eye surgery. Optometrists are more clinically oriented than opticians, who make spectacle lenses, but have fewer clinical privileges than ophthalmologists (see ophthalmology).

OR

OR abbreviation for odds ratio.

or rule

or rule see addition rule.

or-

OR abbreviation for odds ratio.

ora serrata

ora serrata the most anterior portion of the retina, located adjacent to the ciliary body. The normal retinal layers are attenuated in the ora serrata. Also called ora terminalis.

oral administration

oral administration see administration.

oral behavior

oral behavior activities involving the mouth, such as thumb sucking, smoking, eating, kissing, nail biting, talking, and oral sex.

oral character

oral character see oral personality.

oral coitus

oral coitus see fellatio.

oral contraceptive

oral contraceptive a tablet taken regularly by women to prevent pregnancy. Most oral contraceptives are combined formulations of a synthetic estrogen and a progestin; some are progestin-only formulations. The synthetic hormones in these pills alter the normal menstrual activities so that ovulation and related functions are prevented. Introduced in 1960, this type of contraceptive became known popularly simply as “the Pill.”

oral eroticism

oral eroticism in psychoanalytic theory, the pleasure derived from oral activities such as smoking, drinking, chewing, biting, talking, kissing, and orogenital activity. Also called oral erotism; oral gratification. See also orality.

oral gratification

oral gratification see oral eroticism.

oral history

oral history personal background information provided by an individual during an interview. Oral histories may describe perceptions and thoughts, experiences of important events, family relationships, and other personal details. They can be collected, transcribed, and analyzed as part of research studies.

oral method

oral method see oralism.

oral personality

oral personality in classical psychoanalytic theory, a pattern of personality traits derived from fixation at the oral stage of psychosexual development. If the individual has experienced sufficient sucking satisfaction and adequate attention from the mother during the oral-sucking phase, he or she is posited to develop an oral-receptive personality marked by friendliness, optimism, generosity, and tolerance of dependency on others, allowing the individual to move on to late stages of psychosexual development. If the individual does not get enough satisfaction during the sucking and biting phases (see oral-biting phase), he or she is posited to develop an oral-aggressive personality marked by tendencies to be hostile, critical, envious, and exploitative. Also called oral character. [identified by German psychoanalyst Karl Abraham (1877–1925)]

oral phase

oral phase see oral stage.

oral sadism

oral sadism in classical psychoanalytic theory, the primitive urge to use the mouth, lips, and teeth as instruments of aggression, mastery, or sadistic sexual gratification. This impulse is believed to originate in the oral-biting phase of infancy.

oral sex

oral sex stimulation of the external genitals by the partner’s mouth. Oral sex may be carried out to the point of orgasm or done as part of foreplay. It is not uncommon for people to classify oral sex as not really sex; for example, research has shown that some adolescents who have experienced oral sex to orgasm but have not participated in vaginal intercourse perceive themselves as still being virgins. See also orogenital activity.

oral sound

oral sound a speech sound produced by airflow through the cavity of the mouth with little or no nasal quality in its production.

oral stage

oral stage in the classical psychoanalytic theory of Sigmund Freud, the first stage of psychosexual development, occupying the 1st year of life, in which the libido is concentrated on the mouth as the principal erotic zone. The stage is divided into the early oral-sucking phase, during which gratification is achieved by sucking the nipple during feeding, and the later oral-biting phase, when gratification is also achieved by biting. Fixation during each of these phases is posited to cause a particular type of oral personality. Also called oral phase. See also oral eroticism.

oral-aggressive personality

oral-aggressive personality see oral personality.

oral-biting phase

oral-biting phase in classical psychoanalytic theory, the second phase of the oral stage of psychosexual development, from about the 8th to the 18th month of life. During this phase, the child begins to feel that he or she is an autonomous person, develops ambivalent attitudes toward the mother, and expresses hostility by biting her breast or the nipple of the bottle. In later childhood, the urge to bite may take the form of nail-biting, spitting, sticking out the tongue, or chewing on a pencil or gum. Also called oral-sadistic phase. Compare oral-sucking phase. See oral sadism. [identified by German psychoanalyst Karl Abraham (1877–1925)]

oral-receptive personality

oral-receptive personality see oral personality.

oral-sadistic phase

oral-sadistic phase see oral-biting phase.

oral-sucking phase

oral-sucking phase in classical psychoanalytic theory, the earliest part of the oral stage of psychosexual development, in which the nursing infant is posited to feel that he or she is ingesting the mother’s being along with the milk swallowed (see incorporation). This phase is believed to lay the foundation for feelings of closeness and dependence, as well as for possessiveness, greed, and voraciousness. Compare oral-biting phase. [identified by German psychoanalyst Karl Abraham (1877–1925)]

oral–genital contact

oral–genital contact see orogenital activity.

oral–lingual dyskinesia

oral–lingual dyskinesia see buccolingual masticatory syndrome.

oral–motor feeding problem

oral–motor feeding problem a severe difficulty with sucking and swallowing typically seen in children who are born prematurely (related to immature motor development) or in children with motor disorders such as cerebral palsy. Compare feeding problem.

Oralet

Oralet n. a trade name for fentanyl.

oralism

oralism n. a method of improving the communication skills of individuals with hearing loss that focuses on the use of residual hearing, lipreading, and speech and de-emphasizes or prohibits the use of sign language and other manual forms of communication. Also called oral method.

orality

orality n. in psychoanalytic theory, the oral factor in eroticism or neurosis, ranging from pleasure in biting, sucking, smoking, or oral sex to such habits as speech-making, overeating, and alcoholism.

Orap

Orap n. a trade name for pimozide.

Orbison illusion

Orbison illusion any one of a group of geometric illusions in which a figure or a line with straight edges, or a circle, appears distorted by a background pattern of repeated lines. [William Dillard Orbison (1911–1952), U.S. psychologist]

orbitofrontal cortex

orbitofrontal cortex the cerebral cortex of the ventral part of each frontal lobe, having strong connections to the hypothalamus. Lesions of the orbitofrontal cortex can result in loss of inhibitions, forgetfulness, and apathy broken by bouts of euphoria, as in the well-known case of Phineas Gage.

orchidectomy

orchidectomy n. the surgical removal of a testis. An orchidectomy may be performed when a testis is injured or diseased, as when the male reproductive system has been affected by cancer. It does not necessarily cause impotence but may reduce the desire for coitus. Orchidectomy performed before puberty can affect the development of secondary male sex characteristics. Also called orchiectomy. See also castration.

order

order n. in biological taxonomy, a main subdivision of a class, containing a group of similar, related families.

order effect

order effect 1. in within-subjects designs, the influence of the order in which treatments are administered, such as the effect of being the first administered treatment (rather than the second, third, and so forth). As individuals participate in first one and then another treatment condition, they may experience increased fatigue, boredom, and familiarity with or practice with reacting to the independent variable. Any of these conditions could affect the participants’ responses and confound the results of the study. Researchers often use counterbalancing to control for order effects. See also carryover effect; sequence effect. 2. the influence of the order in which items or statements are listed on surveys and questionnaires. Three basic types of question order effect have been identified: (a) unconditional, in which the answer to a subsequent question is affected by the individual having responded to the prior question but not by the response given on that prior question; (b) conditional, in which the answer to a subsequent question depends on the response given to the prior question; and (c) associational, in which the correlation between the prior and subsequent questions changes depending on which is asked first. Order effects make it difficult to know whether change over time reflects legitimate respondent differences or question effects.

order of magnitude

order of magnitude the approximate degree or strength of a number or value within a range, usually to the nearest power of 10. For example, 2,500 (2.5 x 103) and 4,300 (4.3 x 103) are of the same order of magnitude, but both are one order of magnitude greater than 240 (2.4 x 102).

ordered scale

ordered scale see ordinal scale.

orderliness

orderliness n. the tendency to be neat and tidy and to keep everything in place. Excessive orderliness may be a symptom of obsessive-compulsive disorder or obsessive-compulsive personality disorder.

ordinal

ordinal adj. pertaining to rank, order, or position in a series. Compare cardinal; nominal.

ordinal data

ordinal data numerical values that represent rankings along a continuum from lowest to highest, as in a judge’s assignment of a 2 to denote that a particular athlete’s performance was fair and a 3 to denote that a subsequent athlete’s performance was better. Ordinal data may be counted (i.e., how many athletes obtained a 2, how many a 3, etc.) and arranged in descending or ascending sequence but may not be manipulated arithmetically—such as by adding, subtracting, dividing, or multiplying any rank by any other—because the actual difference in performance between adjacent values is unspecified and may vary. In other words, one does not know how much better a rank of 3 is than a 2, and the difference between a 2 and a 3 may not be the same as the difference between a 3 and a 4.

ordinal scale

ordinal scale a sequence of numbers that do not indicate magnitude or a true zero point but rather reflect a rank ordering on the attribute being measured. For example, an ordinal scale for the performance of a specific group of people on a particular test might use the number 1 to indicate the person who obtained the highest score, the number 2 to indicate the person who obtained the next highest score, and so on. It is important to note that an ordinal scale does not provide any information about the degree of difference between adjacent ranks (e.g., it is not clear what the actual point difference is between the rank 1 and 2 scores). Compare interval scale; nominal scale; ratio scale.

ordinal variable

ordinal variable a variable whose possible values have a clear rank order. For example, attitude is an ordinal variable as it may be denoted with ordered points indicating increasing or decreasing values, such as 1 = strongly disagree, 2 = disagree, 3 = agree, and 4 = strongly agree. Values on an ordinal variable indicate that one data point is higher or lower than another but do not define the extent of the difference between them. Compare interval variable.

ordinality

ordinality n. a basic understanding of “more than” and “less than” relationships.

ordinary creativity

ordinary creativity see everyday creativity.

ordinary least squares regression

ordinary least squares regression see least squares regression.

ordinate

ordinate n. the vertical coordinate in a graph or data plot; that is, the y-axis. See also abscissa.

Orestes complex

Orestes complex in classical psychoanalysis, a son’s repressed impulse to kill his mother, which may result in the actual act of matricide. The name is derived from the Greek myth of Orestes, who killed his mother, Clytemnestra, and her lover, Aegisthus.

orexin

orexin n. any of a group of proteins, expressed in the lateral hypothalamus, that trigger feeding and have also been implicated in narcolepsy.

orexis

orexis n. the affective, appetitive character of an activity or behavior, as opposed to the cognitive aspects. Also called orexia. —orectic adj.

organ inferiority

organ inferiority the sense of being deficient or somehow less than others as a result of negative feelings about any type of real or imagined abnormality of organ function or structure. See inferiority complex. [defined by Alfred Adler]

organ language

organ language in the context of classical psychoanalytic explanations of psychosomatic illness, the bodily expression of emotional conflict or disturbance. Some believe that understanding the significance to the patient of the organ affected by the illness is essential for accurate diagnosis and treatment. For example, chronic lumbago (lower backache) with no identifiable organic cause may mean that the patient is feeling put upon, is being a martyr, or is aiming too low in life. Also called organ speech.

organ of Corti

organ of Corti a specialized structure that sits on the basilar membrane within the cochlea in the inner ear. It contains the hair cells (the sensory receptors for hearing), their nerve endings, and supporting cells. See also Deiters cells; tectorial membrane. [Alfonso Corti (1822–1876), Italian anatomist]

organ speech

organ speech see organ language.

organelle

organelle n. a specialized, membrane-bound structure within a cell, such as a mitochondrion or the Golgi apparatus.

organic

organic adj. 1. denoting a condition or disorder that results from structural alterations of an organ or tissue. In psychology and psychiatry, the term is equivalent to somatic or physical, as contrasted with functional or psychogenic. 2. relating to the fundamental, or essential, make-up of a thing, situation, or phenomenon and to the interworking of its components.

organic amnesia

organic amnesia see amnesia.

organic approach

organic approach the perspective that all mental disorders have a physiological basis, resulting from structural brain changes or alterations in other bodily organs. Also called organicism.

organic defect

organic defect a congenital defect that is not the result of a genetic anomaly. For example, a mental or physical defect in offspring can result from maternal illness or other conditions in pregnancy, including preeclampsia, viral infections (e.g., rubella), sexually transmitted infections, protozoan infections (e.g., toxoplasmosis), dietary deficiencies, or drug abuse (e.g., alcoholism).

organic disorder

organic disorder any disorder resulting from a demonstrable abnormality in the structure or biochemistry of body tissues or organs. Also called organic disease. Compare psychogenic disorder.

organic hallucinations

organic hallucinations hallucinations associated with a specific brain-based factor. Stimulation or irritation of part of the brain or a sensory pathway may be a factor, and precipitating causes include aneurysm, tumor, epilepsy, drug use (including some prescribed drugs), and abuse of alcohol, cocaine, amphetamines, or similar substances.

organic paralysis

organic paralysis loss of function of voluntary muscles due to structural lesions of the nervous or muscular system. Compare conversion paralysis.

organic retardation

organic retardation failure of an organ or organ system to develop normally because of a genetic defect, dietary deficiency, or hormonal disorder.

organic selection

organic selection see Baldwin effect.

organic sensation

organic sensation a sensation that arises from deep within the body (e.g., a rumbling stomach). Also called visceral sensation.

organic therapies

organic therapies somatic treatments for serious or recalcitrant mental disorder, among which are electroconvulsive therapy, psychopharmacotherapy, and psychosurgery.

organic variable

organic variable a process or state within an organism that combines with a stimulus to produce a particular response. For example, a headache may be an organic variable, and the response may be an irritable reaction to a stimulus (e.g., noise in the neighborhood). Also called O variable.

organicism

organicism n. see organic approach.

organicity

organicity n. a former term for brain damage or dysfunction.

organicity test

organicity test an obsolete name for a cognitive or behavioral test that has been shown to be differentially sensitive to the effects of brain damage or dysfunction. See neuropsychological test.

organism

organism n. an individual living entity, such as an animal, plant, or bacterium, that is capable of reproduction and growth.

organismic

organismic adj. having components (organs) serving various functions that interact to produce the integrated, coordinated total functioning that characterizes an organism.

organismic model

organismic model the theory that development is directed by constraints inherent in the relationship among elements within the organism as they act upon themselves and each other. Not only are biological processes (e.g., maturation) seen as critical in directing development, but so also are the behaviors of the organism. See developmental systems approach.

organismic personality theory

organismic personality theory an approach to personality theory in which personal functioning is understood in terms of the action of the whole, coherent, integrated organism, rather than in terms of psychological variables representing one versus another isolated aspect of body or mind. [developed by Kurt Goldstein and Hungarian psychologist Andras Angyal (1902–1960)]

organismic psychology

organismic psychology an approach to psychology that emphasizes the total organism, rejecting distinctions between mind and body. It embraces a molar approach that takes account of the interaction between the organism and its environment. See holism; holistic psychology.

organismic valuing process

organismic valuing process in client-centered theory, the presumed healthy and innate internal guidance system that a person can use to achieve self-actualization. One goal of treatment within the client-centered framework is to help the client listen to this inner guide. See client-centered therapy.

organismic variable

organismic variable one of the four factors considered in behavioral assessment using the SORC system, referring to the physiological and psychological features of the organism that influence behavior.

organization

organization n. 1. a structured entity consisting of various components that interact to perform one or more functions. Business, industrial, and service entities are constituted in this way. 2. in Gestalt psychology, an integrated perception composed of various components that appear together as a single whole, such as a face. See gestalt principles of organization. 3. in memory research, the structure discovered in or imposed upon a set of items in order to guide memory performance. 4. in Piagetian theory, the coordinated biological activities of the organism as determined by genetic factors, interactions with the environment, and level of maturation. Inherent in this theory is the concept that every intellectual operation is related to all other acts of intelligence. Such mental processes become increasingly organized, initially developing through reflex behavior and responses to immediate stimulation and gradually becoming self-sustaining, self-generating, and capable of reflecting the child’s own thoughts. See functional invariant. —organizational adj.

organizational approach

organizational approach in the study of emotion, a conceptual framework, based on general systems theory, that emphasizes the role of emotions as regulators and determinants of both intrapersonal and interpersonal behaviors, as well as stressing the adaptive role of emotions. The organizational approach also emphasizes how perception, motivation, cognition, and action come together to produce important emotional changes.

organizational assessment

organizational assessment activities involved in evaluating the structure, process, climate, and other environmental factors that influence the effectiveness of an organization and the morale and productivity of employees. General or specific evaluations (e.g., of readiness to change, job satisfaction, turnover) may be performed by practitioners from a variety of disciplines, including consulting psychology and industrial and organizational psychology.

organizational behavior management (OBM)

Sorry, "organizational-behavior-management-obm" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

organizational career

organizational career see protean career.

organizational citizenship behavior (OCB)

Sorry, "organizational-citizenship-behavior-ocb" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

organizational climate

organizational climate the general character of the total organizational environment as perceived by those who work within it. It is an expression of the organizational culture.

organizational commitment

organizational commitment an employee’s dedication to an organization and wish to remain part of it. Organizational commitment is often described as having both an emotional or moral element (affective commitment) and a more practical element (continuance commitment).

organizational culture

organizational culture a distinctive pattern of thought and behavior shared by members of the same organization and reflected in their language, values, attitudes, beliefs, and customs. The culture of an organization is in many ways analogous to the personality of an individual. See also attraction–selection–attrition model; occupational culture.

organizational culture analysis

organizational culture analysis a comprehensive organizational development intervention in which groups of managers and employees meet to describe the organizational culture and identify those aspects of the culture that are helpful to achieving the goals of the organization and those that are hindrances. [developed by Swiss-born U.S. psychologist Edgar H. Schein (1928– )]

organizational development (OD)

Sorry, "organizational-development-od" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

organizational dynamics

organizational dynamics those forces and processes that stimulate growth, development, and change within an organization. See group dynamics; social dynamics.

organizational effect

organizational effect a long-term effect of hormonal action typically occurring in fetal development or the early postnatal period that leads to permanent changes in behavior and neural functioning. For example, the presence of testosterone in young male rats leads to long-term male-typical behavior, and female rats can be masculinized by neonatal exposure to testosterone. Compare activational effect.

organizational effectiveness

organizational effectiveness a multidimensional construct defining the degree of success achieved by an organization. According to a goal-attainment model, effectiveness is the extent to which the organization is able to achieve its goals in an efficient manner. According to a system model of evaluation, effectiveness is the organization’s ability to achieve long-term survival, which involves acquiring resources, adapting to changes in the environment, and maintaining the internal health of the system. From an ecological perspective, effectiveness is the ability of the organization to minimally satisfy the expectations of its strategic constituencies. All of these factors and more could be included in an assessment of an organization’s effectiveness.

organizational efficiency

organizational efficiency see efficiency.

organizational hierarchy

organizational hierarchy the chain of command in an organization, defining levels of authority and responsibility. Individuals occupying higher positions in the hierarchy have greater power than those lower in the hierarchy.

organizational hypothesis

organizational hypothesis the hypothesis that steroids produced by the newly formed testis during development masculinize the developing brain to alter behavior permanently.

organizational identification

organizational identification a form of group identification in which an employee defines himself or herself in terms of involvement or membership in a particular corporation or other type of workplace. A growing body of evidence indicates that organizational identification underpins a range of important outcomes in work settings.

organizational justice

organizational justice employee perceptions of how fair an organization is. It consists of perceptions of the fairness of outcomes that employees receive (distributive justice) and the fairness of the procedures used in distributing these outcomes (procedural justice). See also equity theory.

organizational politics

organizational politics behavior by individuals in an organization that is intended to further their own interests or the interests of a particular unit or department over the interests of other individuals or units.

organizational psychology

organizational psychology see industrial and organizational psychology.

organizational structure

organizational structure the arrangement and interrelationship of the various parts or elements of an organization. Organizational structures can be described on several dimensions, including simple versus complex, centralized versus decentralized, and hierarchical versus nonhierarchical. A distinction can also be made between the formal organizational structure and the informal structures of an organization.

organized offender

organized offender the type of offender who carefully plans his or her crimes and who is typically more intelligent and less socially isolated than disorganized offenders. This distinction is useful when profiling violent offenders (see criminal profiling).

organogenesis

organogenesis n. 1. the formation of organs during development. 2. see somatogenesis. —organogenic or organogenetic adj.

organum vasculosum of the lamina terminalis (OVLT)

Sorry, "organum-vasculosum-of-the-lamina-terminalis-ovlt" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

orgasm

orgasm n. the climax of sexual stimulation or activity, when the peak of pleasure is achieved, marked by the release of tension and rhythmic contractions of the perineal muscles, anal sphincter, and pelvic reproductive organs. In men, orgasm is also accompanied by the emission of semen (ejaculation); in women, it is accompanied by contractions of the wall of the outer third of the vagina. See also sexual-response cycle. —orgasmic or orgastic adj.

orgasmic dysfunction

orgasmic dysfunction an inability to reach orgasm in general or with certain forms of sexual stimulation. Principally occurring in women, it may be primary, in which a woman has never been able to achieve an orgasm with any type of stimulation, with or without a partner; secondary, in which a woman had previously been but is currently unable to attain orgasm through physical contact; or situational, in which a woman is unable to experience orgasm with a particular partner or in a particular situation. See also female orgasmic disorder; male orgasmic disorder; premature ejaculation.

orgasmic phase

orgasmic phase see sexual-response cycle.

orgasmic platform

orgasmic platform the vascular tissue at the outer portion of the vagina and the labia minora that becomes engorged during sexual arousal or coitus.

orgasmic reconditioning

orgasmic reconditioning a behavioral treatment aimed at altering the deviant sexual preferences of individuals who commit sex offenses, including rape, pedophilia, and child molestation. The technique has been inappropriately applied to alter homosexual behavior as well. In the treatment as initially formulated in 1970 by clinical psychologist John N. Marquis, participants masturbate to deviant materials (e.g., pictures, videos) and just prior to orgasm switch to nondeviant material. Individuals gradually introduce the nondeviant imagery earlier and earlier in the process, so as to eventually associate only the nondeviant theme with the pleasurable experience of orgasm and to supplant deviant sexual arousal patterns altogether. Several variations of the original procedure exist, including one in which masturbation occurs in a laboratory and physiological responses (e.g., changes in penile tumescence and heart rate) to stimuli are measured; one in which deviant and nondeviant themes are alternated weekly or daily; and one in which deviant imagery is omitted entirely. Despite its promotion by some clinicians as a useful technique for treating sexual deviance, orgasmic reconditioning has little empirical support; there is limited evidence to suggest its success as one component of a comprehensive behavioral change program. Also called masturbatory reconditioning.

orgastic potency

orgastic potency the ability of a man or woman to achieve full orgasm during the sex act. [first used by Wilhelm Reich (1897–1957), Austrian psychoanalyst]

orgone

orgone n. the “life energy” and creative force in nature that was believed by Austrian psychoanalyst Wilhelm Reich (1897–1957) to pervade the universe. According to Reich, orgone was emitted by energy vesicles called “bions,” which he claimed to find in organic material. He also posited that it related to cosmic radiation and speculated that it might be responsible for the origin of life from earth and water (biogenesis), as well as the formation of weather patterns and the sexual potency of human beings.

orgone therapy

orgone therapy the therapeutic approach of Austrian psychoanalyst Wilhelm Reich (1897–1957), based on the concept that the achievement of “full orgastic potency” is the key to psychological well-being. Reich believed the orgasm to be the emotional-energy regulator of the body, the purpose of which is to dissipate sexual tensions that would otherwise be transformed into neuroses. He further held that the orgasm derives its power from a hypothetical cosmic force, orgone energy, which accounts not only for sexual capacity but also for all functions of life. The psychoanalytic community largely rejected Reich’s highly unorthodox theories and approaches. Also called vegetotherapy.

orgy

orgy n. a type of social gathering at which a number of people engage in unrestrained sexual activity, often with other forms of revelry, including singing, dancing, and drinking. —orgiastic adj.

oriental nightmare-death syndrome

oriental nightmare-death syndrome see bangungut.

orientation

orientation n. 1. awareness of the self and of outer reality; that is, the ability to identify one’s self and to know the time, the place, and the person one is talking to. See also reality orientation. 2. the act of directing the body or of moving toward an external stimulus, such as light, gravity, or some other aspect of the environment. 3. in vision, the degree of tilt of the long axis of a visual stimulus. For example, a vertical bar is oriented at 0°; a horizontal bar is oriented at 90°. Many neurons in the visual system respond most vigorously to a stimulus of a certain orientation: They are said to be orientation selective. See also orientation column. 4. relative position or alignment, for example, of a body part or an atom in a chemical compound. 5. the process of familiarizing oneself with a new setting (e.g., a new home, neighborhood, city) so that movement and use do not depend upon memory cues, such as maps, and eventually become habitual. 6. an individual’s general approach, ideology, or viewpoint. 7. the process of introducing a newcomer to a job, company, educational institution, or other environment. —orient vb.

orientation and mobility training (O＆M training)

Sorry, "orientation-and-mobility-training-om-training" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

orientation column

orientation column a vertical slab of striate cortex in which all the neurons are maximally responsive to stimuli of the same orientation. Adjacent columns have slightly different orientation preferences, so that electrode penetration tangential to the cortical surface that passes through many columns would encounter neurons with orientation preferences that shift smoothly around a reference axis. Compare ocular dominance column. [first described in the 1960s and 1970s by U.S. neurophysiologist David Hubel (1926–2013) and Swedish neurophysiologist Torsten Wiesel (1924– )]

orientation illusion

orientation illusion see illusion of orientation.

orienting response

orienting response 1. a behavioral response to an altered, novel, or sudden stimulus, such as turning one’s head toward an unexpected noise. Physiological components of the orienting response have been identified as well, including dilation of pupils and blood vessels and changes in heart rate and electrical resistance of the skin. [described in 1927 by Ivan Pavlov] 2. any response of an organism in relation to the direction of a specific stimulus. See taxis; tropism. Also called orienting reflex.

origin-of-language theory

origin-of-language theory see language-origin theory.

original cause

original cause the first or primary cause of a phenomenon; that is, the first in a sequence of causes producing a particular effect. See causal chain; remote cause.

original sin

original sin in the Judeo-Christian tradition, a state of sin held to be innate in all humankind as a result of the first sin committed by Adam and Eve, which led to their expulsion from the Garden of Eden. Although modern theologians tend to interpret this story symbolically rather than historically, the idea that there is a kind of hereditary stain or fundamental flaw in human nature remains important in Christian thought. The doctrine of original sin has sometimes been reinterpreted in psychological, existential, or socioeconomic terms.

originality

originality n. see creativity.

Orne effect

Orne effect the tendency for typical study participants to try to discern the wishes or intent of an experimenter and to try to respond in accordance with these wishes or intent. See demand characteristics. [Martin T. Orne]

ornithinemia

ornithinemia n. an excess of the amino acid ornithine in the blood, possibly due to an inborn error of amino acid metabolism or to liver disease.

oro- (or-)

Sorry, "oro-or" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

orofacial apraxia

orofacial apraxia see apraxia.

orofacial dyskinesia

orofacial dyskinesia behavior characterized by abnormal chewing, mouthing, and tongue movements that resemble symptoms of tardive dyskinesia.

orogenital activity

orogenital activity stimulation of the genitalia by the mouth or tongue. The activity may be performed by heterosexual or homosexual couples, either as a precoital form of stimulation or carried to orgasm. Application of the mouth to the male genitalia is called fellatio; application of the mouth to the female genitalia is known as cunnilingus. Also called buccal intercourse; oral–genital contact. See also oral sex.

oropharynx

oropharynx n. the portion of the pharynx at the back of the mouth, extending from the level of the hyoid bone (at the base of the tongue) to the soft palate. It contains the functional crossing of the alimentary and respiratory canals. —oropharyngeal adj.

orphanin FQ

orphanin FQ see endogenous opioid; opioid receptor.

orphenadrine

orphenadrine n. an anticholinergic drug used in the treatment of drug-induced parkinsonian symptoms, such as those produced by conventional antipsychotics, and for the relief of localized muscle spasms (see muscle relaxant). Orphenadrine is sold in combination with analgesics (e.g., with aspirin and caffeine as Norgesic in the United States). U.S. trade name: Norflex.

Ortgeist

Ortgeist n. German, “spirit of a place”: the influence of the physical or cultural environment on the development of social, economic, and artistic life in a particular place. See also Zeitgeist.

orthergasia

orthergasia n. see euergasia.

ortho- (orth-)

Sorry, "ortho-orth" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

Ortho-Rater

Ortho-Rater n. a portable visual testing device used for the rapid assessment of visual acuity, color vision, and depth perception. It is commonly used in the United States to test the vision of individuals applying for a driver’s license.

orthodox psychoanalysis

orthodox psychoanalysis see classical psychoanalysis.

orthodox sleep

orthodox sleep a less common name for NREM sleep.

orthogenesis

orthogenesis n. 1. the theory that the evolution of a species follows a direction determined by factors inherent to its organisms and that successive generations follow the same plan irrespective of natural selection. 2. the theory that all cultures pass through the same sequential stages. —orthogenetic adj.

orthogenetic principle

orthogenetic principle the hypothesis that development of all aspects of functioning (including cognition, perception, etc.) progresses from lack of differentiation to increasing differentiation, articulation, and hierarchic integration. [proposed in 1957 by Heinz Werner]

orthogonal

orthogonal adj. 1. describing a set of axes at right angles to one another, which in graphical representations of mathematical computations (such as factor analysis) and other research indicates uncorrelated (unrelated) variables. Compare oblique. 2. denoting a research design in which there are an equal or proportional number of participants across study conditions. See orthogonal design.

orthogonal coding

orthogonal coding see contrast coding.

orthogonal contrast

orthogonal contrast in a factorial analysis of variance, a set of nonredundant comparisons among the mean values for different samples. In other words, the set contains no overlapping information, so that the results from one comparison provide no information about the results of the second comparison. Also called orthogonal comparison.

orthogonal design

orthogonal design an experimental design involving multiple independent variables in which each level of one variable is combined with each level of every other and in which all of the resulting conditions contain an equal or proportional number of participants or observations.

orthogonal rotation

orthogonal rotation a transformational system used in factor analysis in which the different underlying or latent variables are required to remain separated from or uncorrelated with one another. It is one of two types of factor rotation used to identify a simpler structure pattern or solution, the other being oblique rotation. Also called rigid rotation.

orthographic distinctiveness effect

orthographic distinctiveness effect see distinctiveness effect.

orthography

orthography n. 1. the formal writing system of a language. 2. the study of the conventions of spelling in such a system. —orthographic adj.

orthokinesis

orthokinesis n. an increase (positive orthokinesis) or decrease (negative orthokinesis) in the speed or frequency of movement, particularly in relation to increases or decreases in stimulation. —orthokinetic adj.

orthomolecular medicine

orthomolecular medicine a form of complementary and alternative medicine that uses megavitamin therapy and other nutritional approaches to prevent or treat physical and mental disorders. Proponents of this approach believe that biochemical imbalances in the body are a contributing factor to disease and that using vitamins, minerals, and other substances natural to the body corrects these imbalances. Also called orthomolecular therapy. [conceived in 1968 by U.S. biochemist Linus Pauling (1901–1994)]

orthonasal olfaction

orthonasal olfaction sensations of smell arising via the introduction of an odorant through the nostrils. This is the common route for olfactory sensation. Compare retronasal olfaction.

orthopedic cane

orthopedic cane see cane.

orthopsychiatry

orthopsychiatry n. an interdisciplinary approach to mental health in which psychiatrists, psychologists, social workers, pediatricians, sociologists, nurses, and educators collaborate on the early treatment of mental disorders, with an emphasis on their prevention. —orthopsychiatric adj. —orthopsychiatrist n.

orthoptics

orthoptics n. 1. the study and treatment of faulty binocular vision. 2. the use of eye exercises to coordinate the vision in the left and right eyes of individuals with extrinsic eye muscle imbalance. —orthoptic adj. —orthoptist n.

orthoptoscope

orthoptoscope n. see amblyoscope.

orthorexia nervosa

orthorexia nervosa an obsessive concern with eating a healthy or “pure” diet that is typically very restrictive and more focused on wellness than weight loss. Individuals may insist on eating only certain foods (e.g., those grown locally) or avoid certain food groups altogether (e.g., meat, eggs, dairy, wheat products), often resulting in extremely low caloric intake, risk of malnutrition, and in extreme cases, death. There is some debate about whether orthorexia nervosa is a distinct disorder or a form of anorexia nervosa or obsessive-compulsive disorder. [described in 1997 by U.S. physician Steven Bratman]

orthostatic hypotension

orthostatic hypotension a drop in blood pressure when moving from a lying or sitting position to a standing position. Blood pressure is normally maintained during changes in position by activation of baroreceptors in the walls of the heart and the major arteries. Activation of these receptors in turn activates alpha-adrenergic receptors in peripheral blood vessels, leading to arterial constriction and maintenance of blood pressure. Numerous psychotropic drugs (e.g., antidepressants, antipsychotics) block the activity of peripheral alpha-adrenergic receptors, leading to orthostatic hypotension and an increased risk of falls, particularly in older adults. Orthostatic hypotension can also be caused by such disorders as diabetes mellitus, amyloidosis, and Parkinson’s disease. Also called postural hypotension.

orthotics

orthotics n. a medical specialization concerned with the fitting and use of braces and other orthopedic (supportive or corrective) devices. Compare prosthetics.

oscillator circuit

oscillator circuit a circuit that produces a repeating pattern of output. Unlike an endogenous oscillator, it is not necessarily biological. For example, oscillator circuits can be found in computers, and the term itself is often associated with artificial neural networks.

oscillatory interference model

oscillatory interference model see grid cell.

oscillograph

oscillograph n. an instrument, often used in studies of bodily functions, that makes graphic recordings of wave forms of electrical energy.

oscillometer

oscillometer n. an instrument for measuring oscillations (variations or fluctuations), especially those associated with bodily functions, such as variations in arterial pulsation.

oscillopsia

oscillopsia n. the sensation of perceiving oscillating movement of the environment. This illusory movement can be caused by (bilateral) vestibular cerebellar injury, paralysis of extrinsic eye muscles, or nystagmus, but it may also be due to cerebral disorders (e.g., seizures, occipital lobe infarction).

oscilloscope

oscilloscope n. an electronic device that records and displays visually an electrical or sound wave on a fluorescent screen of a cathode ray tube.

OSHA

OSHA abbreviation for Occupational Safety and Health Administration.

osmolagnia

osmolagnia n. sexual interest in and pleasure derived from smells emanating from the body, especially from the genitals.

osmolarity

osmolarity n. the concentration of an osmotic solution, measured in osmoles per liter of solution.

osmometer

osmometer n. 1. an instrument for measuring osmotic pressure or the amount of osmotic action (passage across a membrane of solutes from higher to lower concentrations) in different liquids. 2. an early type of olfactometer involving a sealed chamber containing an odorant. The participant opened the chamber, inhaled, and reported the odor detected.

osmometric thirst

osmometric thirst thirst resulting from a loss of cellular fluids and a relative increase in osmotic pressure. Also called intracellular thirst; osmotic thirst. Compare hypovolemic thirst.

osmoreceptor

osmoreceptor n. a hypothetical receptor in the hypothalamus that responds to changes in the concentrations of various substances in the body’s extracellular fluid and to cellular dehydration. It also regulates the secretion of vasopressin and contributes to thirst.

osmoregulation

osmoregulation n. a complex mechanism for maintaining the optimum content of water and electrolytes in the body cells and extracellular fluid of an organism. Also called water regulation.

osmosis

osmosis n. the passive movement of solvent molecules through a differentially permeable membrane (e.g., a cell membrane) separating two solutions of different concentrations. The solvent tends to flow from the weaker solution to the stronger solution. —osmotic adj.

osmotic pressure

osmotic pressure the pressure required to prevent the passage of water (or other solvents) through a semipermeable membrane (e.g., a cell membrane) from an area of low concentration of solute to an area of higher concentration. It results from the spontaneous movement of molecules that occurs when different concentrations are separated by a semipermeable membrane.

OSpan

OSpan abbreviation for operation span.

osphresiolagnia

osphresiolagnia n. sexual arousal or erotic experience produced by odors.

osphresiophilia

osphresiophilia n. an abnormal attraction to odors.

osseous labyrinth

osseous labyrinth see labyrinth.

ossicles

ossicles pl. n. any small bones, but particularly the auditory ossicles: the chain of three tiny bones in the middle ear that transmit sound vibrations from the tympanic membrane (eardrum) to the oval window of the inner ear. They are the malleus (or hammer), which is attached to the tympanic membrane; the incus (or anvil); and the stapes (or stirrup), whose footplate nearly fills the oval window. The ossicles allow efficient transmission of sound from air to the fluid-filled cochlea.

osteomalacia

osteomalacia n. see calcium-deficiency disorders.

osteopathy

osteopathy n. a health care system based on the belief that many disorders are caused by structural defects in the musculoskeletal system. It focuses on primary care, prevention, a holistic health approach, and—especially—manipulation of the affected joints and muscles (particularly of the spine) in conjunction with traditional medical, surgical, and pharmacological treatment to address underlying disease processes. Also called osteopathic medicine. See also complementary and alternative medicine. —osteopath n. —osteopathic adj.

osteopetrosis

osteopetrosis n. a rare genetic disorder characterized by increased bone density, which may lead to abnormalities in bone shape or size, due to abnormal resorption (breakdown, removal, and replacement) of bone. Although the bones are highly dense, they are brittle and liable to fracture.

osteoporosis

osteoporosis n. see calcium-deficiency disorders.

ostracism

ostracism n. an extreme form of rejection in which one is excluded and ignored in the presence of others. Ostracism has powerful negative effects on psychological well-being and is detrimental to multiple domains of self-functioning. Specific consequences include not only sadness, hurt feelings, and changes in social perception (e.g., increased likelihood of interpreting ambiguous situations as threatening) but also decreased satisfaction of four fundamental human needs: belonging, control, self-esteem, and meaningful existence. Evidence from both human and nonhuman animal research suggests that ostracism activates the anterior cingulate cortex, the same area of the brain involved in experiencing both physical and psychological pain.

Ostwald color system

Ostwald color system a method of organizing chromatic and achromatic samples. The system consists of 24 hues arranged around the outside of a circle, with the complementary colors for each hue located along the circle’s diameters. By combining adjacent colors, any color on the Ostwald scale can be produced. [Wilhelm Ostwald (1853–1932), German chemist and physicist]

OT

OT abbreviation for occupational therapy.

ot-

OT abbreviation for occupational therapy.

OTC

OTC abbreviation for over-the-counter.

Othello syndrome

Othello syndrome see delusional jealousy. [derived from the name of the protagonist of William Shakespeare’s tragedy Othello]

other-directed

other-directed adj. describing or relating to people whose values, goals, and behavior stem primarily from identification with group or collective standards rather than with individually defined standards. Also called outer-directed. Compare inner-directed; tradition-directed. [introduced by U.S. sociologist David Riesman (1909–2002)]

other–total ratio (OTR)

Sorry, "other-total-ratio-otr" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

otic

otic adj. pertaining to the ear.

Otis–Lennon School Ability Test (OLSAT)

Sorry, "otis-lennon-school-ability-test-olsat" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

otitis media

otitis media an inflammation or infection of the middle ear commonly associated with sinusitis, upper respiratory infections, or allergies. It can result in a conductive hearing loss (see conduction deafness) that generally resolves with symptom treatment. Acute otitis media is common in young children, resulting from viral or bacterial infection. In serous otitis media, a thick fluid fills the middle ear. In adhesive otitis media, permanent adhesions develop in the middle ear due to the continued presence of fluid after the infection itself has been controlled. These adhesions can damage the ossicles.

oto- (ot-)

Sorry, "oto-ot" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

otoacoustic emissions (OAEs)

Sorry, "otoacoustic-emissions-oaes" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

otoconium

otoconium n. (pl. otoconia) see otolith.

otohemineurasthenia

otohemineurasthenia n. a unilateral deafness for which no organic cause can be found.

otolaryngology

otolaryngology n. the medical discipline concerned with the assessment and treatment of diseases of the ears, nose, and throat and associated structures of the head and neck.

otolith

otolith n. any of numerous tiny calcium particles embedded in the gelatinous matrix of the vestibular sacs of the inner ear. See macula. Also called otoconium; statoconium.

otology

otology n. the medical discipline concerned with the study, diagnosis, and treatment of disorders of the ear. —otological adj. —otologist n.

otoneurology

otoneurology n. the study of neurology as related to audition. —otoneurological adj. —otoneurologist n.

otopalatodigital spectrum disorders

otopalatodigital spectrum disorders a group of related X-linked dominant disorders caused by mutations in the FLNA gene. The disorders include otopalatodigital syndrome types 1 and 2, frontometaphyseal dysplasia, and Melnick–Needles syndrome. In general, these disorders involve hearing loss resulting from malformed ossicles, cleft palate or other problems in the development of the roof of the mouth, and skeletal abnormalities in the fingers and toes. Males have more severe symptoms than do females, and males with otopalatodigital syndrome type 2 or Melnick–Needles syndrome do not live beyond their 1st year.

otosclerosis

otosclerosis n. a formation of spongy bone that develops in the middle ear and immobilizes the stapes at the point of attachment to the oval window facing the inner ear. Otosclerosis is marked by progressive deafness as the ossicles fail to transmit vibrations from the tympanic membrane to the inner ear. It is considered hereditary. —otosclerotic adj.

ototoxic

ototoxic adj. damaging to the ears, especially the structures for hearing and balance within the inner ear. —ototoxicity n.

OTR

OTR abbreviation for other–total ratio.

ought self

ought self in analyses of self-concept, a mental representation of a set of attributes that one is obligated to possess according to social norms or one’s personal responsibilities.

Ouija board

Ouija board trade name for a board marked with numbers and letters on which a movable pointer (planchette), touched by the participants, spells out messages under the supposed guidance of spirits. The process can be seen as a form of automatic writing. [from a blend of the French and German words for yes: oui and ja]

out-of-body experience

out-of-body experience a dissociative experience during which the individual imagines or feels that his or her mind, soul, or spirit has left the body and is acting or perceiving independently. Such experiences are sometimes reported by those who have recovered from a near-death experience; they have also been reported by those using hallucinogens or under hypnosis. A significant number have been reported as occurring when the reporter was asleep or falling asleep. Certain occult or spiritualistic practices may also attempt to induce such experiences. See astral projection.

outbreeding

outbreeding n. 1. the mating of humans who are unrelated or who originate from different groups. It is thus the converse of inbreeding. 2. the mating of a nonhuman animal with an unrelated or distantly related member of the same species. This may produce hybrid vigor. Also called crossbreeding.

outcome

outcome n. 1. the result of an experiment, treatment, intervention, or other event. For example, the test scores of students in a classroom who have been taught with a new lecture method comprise an outcome, as does a client’s condition after psychotherapy. 2. in game theory, the factor determining a particular set of payments, one set being paid to each participant. 3. in interdependence theory, the net profit or loss one derives from an interaction after all of one’s benefits and costs are considered. 4. in equity theory, the benefits people receive from their activities (e.g., pay, intrinsic gratification, recognition).

outcome dependence

outcome dependence a social situation in which one person’s outcomes, including the rewards or punishments experienced, are determined in whole or in part by the actions of another person. Compare outcome interdependence. [based on the social exchange theory of John W. Thibaut and Harold H. Kelley as described in their book The Social Psychology of Groups (1959)]

outcome evaluation

outcome evaluation a process used to decide whether a program has achieved its stated goals and had the desired impact on the participants. Also called payoff evaluation. See also impact analysis; summative evaluation.

outcome expectancies

outcome expectancies cognitive, emotional, and behavioral outcomes that individuals believe are associated with future, or intended, behaviors (e.g., alcohol consumption, exercise) and that are believed to either promote or inhibit these behaviors.

outcome interdependence

outcome interdependence a social situation in which two or more people have mutual influence over one another’s outcomes. Compare outcome dependence. [based on the social exchange theory of John W. Thibaut and Harold H. Kelley as described in their book The Social Psychology of Groups (1959)]

outcome measures

outcome measures assessments of the effectiveness of an intervention on the basis of measurements taken before, during, and after the intervention.

outcome research

outcome research a systematic investigation of the effectiveness of a type or technique of intervention (e.g., a new form of psychotherapy for treating depression) or of the comparative effectiveness of different intervention types or techniques (e.g., cognitive behavior therapy vs. drug therapy for depression). In other words, outcome research focuses on determining whether participants benefit from receiving an intervention. Compare process research.

outcome variable

outcome variable see dependent variable.

outer ear

outer ear see external ear.

outer hair cells

outer hair cells see hair cell.

outer nuclear layer

outer nuclear layer the layer of cell bodies of the rods and cones in the retina. Also called outer granular layer.

outer plexiform layer

outer plexiform layer the synaptic layer in the retina in which contacts are made between photoreceptors, retinal bipolar cells, and retinal horizontal cells.

outer psychophysics

outer psychophysics an attempt to establish the direct relationship between the physical intensity of sensory stimuli and the intensity of the related mental experience. Compare inner psychophysics. See psychophysical law. [introduced by Gustav Theodor Fechner]

outer-directed

outer-directed adj. see other-directed.

outercourse

outercourse n. noncoital sexual activity, which may include achieving orgasm by manual stimulation of the genitals or by oral sex.

outgroup

outgroup n. 1. in general, any group to which one does not belong or with which one does not identify. 2. a specific rival group that ingroup members ridicule, derogate, and sometimes are aggressive toward. Also called they-group. [defined in 1906 by U.S. sociologist William G. Sumner (1840–1910)]

outgroup extremity effect

outgroup extremity effect the tendency to describe and evaluate outgroup members, their actions, and their products in extremely positive or extremely negative ways. Compare ingroup extremity effect. See also linguistic intergroup bias.

outgroup homogeneity bias

outgroup homogeneity bias the tendency to assume that the members of other groups are very similar to each other, particularly in contrast to the assumed diversity of the membership of one’s own group. See also group attribution error; group fallacy.

outing

outing n. revealing to others one’s own or another person’s homosexual orientation. The term refers to coming out of the closet (see closet homosexual). —out vb.

outlier

outlier n. an extreme observation or measurement, that is, a score that significantly differs from all others obtained. For instance, assume a researcher administered an intelligence test to a group of people. If most individuals obtained scores near the average IQ of 100 yet one person had an IQ of 150, the latter score would be an outlier. Outliers can have a high degree of influence on summary statistics (e.g., the mean and standard deviation can be pulled severely toward outliers) and on estimates of parameter values, and they may distort research findings if they are the result of error.

outpatient

outpatient n. a person who obtains a diagnosis, treatment, or other service at a hospital, clinic, physician’s office, or other health care facility without overnight admission. See also ambulatory care. Compare inpatient.

outpatient commitment

outpatient commitment a form of court-ordered psychiatric or psychological treatment in which individuals are allowed to remain in the community so long as they are closely monitored and continue to receive treatment.

outpatient services

outpatient services health care services performed for registered ambulatory patients in hospital units, clinics, doctors’ offices, and mental health centers.

outplacement counseling

outplacement counseling practical and psychological assistance given to workers whose employment with an organization has been terminated. It can include vocational guidance and coaching in job-hunting skills as well as psychological help in dealing with the transition. The program is usually conducted by specialty firms outside the organization. See also vocational counseling.

output

output n. in computing contexts, the information a computer produces. Compare input.

output interference

output interference disruption in the recall of learned material during which the act (or process) of retrieving one item interrupts the ability to recall other items. For example, in the attempt to recall a finite set of items (e.g., words on a list, the names of people in a group), the retrieval of some items can interfere with the retrieval of other items in the same set.

outreach

outreach n. activity that brings clinical (e.g., medical or mental health consultation), educational (e.g., class modules providing health information), or practical services (e.g., transportation to clinics or schools) to a community or population that may not otherwise have easy or any access to the services.

ova

ova pl. n. see ovum.

oval window

oval window a membrane-covered opening in the bony wall of the cochlea in the ear (see scala vestibuli). Vibration of the stapes (see ossicles) is transmitted to the oval window and into the cochlear fluids.

ovarian follicle

ovarian follicle see graafian follicle.

ovariectomy

ovariectomy n. the surgical removal of an ovary. This procedure may be performed when the ovaries are diseased or injured. Under some circumstances, as when a woman is at very high risk for ovarian cancer, it may be carried out prophylactically (see prophylactic surgery). Removal of ovaries in premenopausal women will induce menopause. Also called oophorectomy.

ovary

ovary n. the female reproductive organ, which produces ova (egg cells) and sex hormones (estrogens and progesterone). In humans, the two ovaries are almond-shaped organs normally located in the lower abdomen on either side of the upper end of the uterus, to which they are linked by the fallopian tubes. The ovaries of the prepubertal human female contain about 350,000 immature oocytes, of which fewer than 400 will develop into mature ova to be released at a rate of about one per month between menarche (first menstruation) and menopause. See oogenesis. See also graafian follicle; menstrual cycle. —ovarian adj.

over-the-counter (OTC)

Sorry, "over-the-counter-otc" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

overachiever

overachiever n. a person, such as a student, who achieves above his or her capacity as calculated and predicted by aptitude and general-intelligence tests. Some prefer to refer to overachievement as “achievement above predicted expectations.” Compare underachiever.

overactivity

overactivity n. excessive, restless activity that is usually less extreme than hyperactivity.

overage

overage adj. describing a person who is beyond the average or usual age associated with a given behavior or trait. The term is sometimes applied to a child or student who is chronologically older than the others in his or her grade. Underage describes a student who is younger than his or her classmates.

overattribution bias

overattribution bias see fundamental attribution error.

overbreathing

overbreathing n. see hyperventilation.

overclassification

overclassification n. a phenomenon in which, at levels ranging from local schools to national patterns of education, children who are members of ethnic minority groups are at heightened risk of being classified as special education students.

overcompensation

overcompensation n. see compensation. —overcompensate vb.

overconfidence

overconfidence n. a cognitive bias characterized by an overestimation of one’s actual ability to perform a task successfully, by a belief that one’s performance is better than that of others, or by excessive certainty in the accuracy of one’s beliefs. Compare underconfidence. —overconfident adj.

overcontrolled

overcontrolled adj. denoting behavior that is inhibited and constrained, often driven by shyness or fear of rejection. The word is typically used to describe the behavior of children thought to be at risk for depression, but it may also refer to similar behavior in adults.

overcorrection

overcorrection n. in therapy, a technique in which a therapist asks a client who has exhibited inappropriate behavior to repeat the behavior in an appropriate but exaggerated way. Also called positive practice.

overcrowding

overcrowding n. a higher concentration of organisms per unit of space than is customary for a given species. Experimental overcrowding significantly increases abnormal behavior and aggression in rats, even when sufficient resources preclude the need for competition. In human societies, overcrowding is associated with stress but does not inevitably lead to increased aggression. See also density; overpopulation.

overdetermination

overdetermination n. in psychoanalytic theory, the concept that several unconscious factors may combine to produce one symptom, disorder, or aspect of behavior. Because drives and defenses operate simultaneously and derive from different layers of the personality, a single symptom may serve more than one purpose or fulfill more than one unconscious wish. Also called multiple determination. —overdetermined adj.

overdispersion

overdispersion n. in categorical data analysis, a situation in which obtained observations display more variation (dispersion) than is predicted by a model. Overdispersion distorts standard error and confidence interval estimates and is often associated with outliers or model misspecification.

overdose (OD)

Sorry, "overdose-od" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

Overeaters Anonymous (OA)

Sorry, "overeaters-anonymous-oa" is not in the Dictionary of Psychology. Please report to APA if you believe this is an error.

overexpectation

overexpectation n. in classical conditioning, a decrease in responding to two (or presumably more) conditioned stimuli individually after they have been joined into a compound stimulus and then paired with the unconditioned stimulus previously used to establish each part of the compound as an independent conditioned stimulus.

overextension

overextension n. the tendency of very young children to extend the use of a word beyond the scope of its specific meaning, such as by referring to all animals as “doggie.” Compare underextension.

overgeneralization

overgeneralization n. 1. a cognitive distortion in which an individual views a single event as an invariable rule, so that, for example, failure at accomplishing one task will predict an endless pattern of defeat in all tasks. 2. the process of extending something beyond the circumstances to which it actually applies. It is a common linguistic tendency of young children to generalize standard grammatical rules to apply to irregular words (e.g., pluralizing foot to foots). See overextension; overregularization.

overheating

overheating n. excessive ambient temperature. See heat effects.

overidentification

overidentification n. in structural equation modeling and similar statistical techniques, the presence of more parameters in a model than are required to correctly specify the relationships among the variables of interest. In other words, the number of known parameters exceeds the number of free parameters, allowing one or more values to be estimated in more than one way. Compare underidentification.

overinclusion

overinclusion n. failure of an individual to eliminate ineffective or inappropriate responses associated with a particular stimulus.

overintensity

overintensity n. a state in which one or more of the following are above the optimal level for an individual’s performance: arousal, commitment, effort, assertiveness, and attentional focus. See intensity.

overjustification effect

overjustification effect a paradoxical effect in which rewarding (or offering to reward) a person for his or her performance can lead to lower, rather than higher, interest in the activity. It occurs when the introduction of an extrinsic reward weakens the strong intrinsic motivation that was the key to the person’s original high performance. Compare insufficient justification effect.

overlapping psychological tasks

overlapping psychological tasks in psychological testing, two tasks that overlap in time. A common finding is that performance of the second task is slowed when the stimulus for it is presented shortly after the stimulus for the first task. See psychological refractory period.

overlapping waves theory

overlapping waves theory the proposition that during development children rely on a variety of old and new information-processing strategies concurrently, with these strategies waxing and waning over time. [proposed by U.S. developmental psychologist Robert S. Siegler (1949– )]

overlearning

overlearning n. practice that is continued beyond the point at which the individual knows or performs the task as well as can be expected. The benefits of overlearning may be seen in increased persistence of the learning over time or better retention and memory. —overlearned adj.

overload

overload n. a psychological condition in which situations and experiences are so cognitively, perceptually, and emotionally stimulating that they tax or even exceed the individual’s capacity to process incoming information. Compare underload. See cognitive overload; information overload; sensory overload; stimulus overload.

overload principle

overload principle a concept stating that to increase the size or functional ability of muscle fibers, they must be pushed close to the limit of their current ability to respond.

overmatching

overmatching n. 1. unnecessary matching: the pairing of research participants on an excessive number of characteristics or on characteristics having little or no potential influence upon the outcome of interest. For example, a researcher investigating a new drug treatment for cancer might create two groups whose members are of the same age and sex, administering the drug to one group and a placebo to the other group. Such group comparability would allow the researcher greater validity in attributing any changes between them to the treatment rather than to sex or age differences. If, however, the researcher were to pair the groups on such additional factors as area of residence and household income, overmatching would be present and likely to mask the true nature of the relationship under investigation and lead to statistical bias, such as by reducing the power and efficiency of analyses. 2. see matching law.

overmedication

overmedication n. see medication.

overpayment inequity

overpayment inequity an employee’s perception that he or she is being paid at a rate that exceeds what is fair, especially in comparison with coworkers. This can lead to dissatisfaction, tension with coworkers, and efforts to restore equity. Compare underpayment inequity. See equity theory.

overpopulation

overpopulation n. a population density that is higher than desirable and may result in overcrowding and stress. Evidence from animal behavior supports the view that overcrowding increases aberrant behavior and aggression. However, some human societies with very high population density have correspondingly low rates of violence and social pathology, suggesting that the negative effects of overpopulation may have social as well as biological origins.

overproduction

overproduction n. the condition in which a species produces too many offspring for the available food, space, or other vital resources.

overprotection

overprotection n. the process of sheltering a child to such an extent that he or she fails to become independent and may experience later adjustment and other difficulties.

overreaction

overreaction n. a response, typically an emotional one, that exceeds an appropriate level.

overregularization

overregularization n. a transient error in linguistic development in which the child attempts to make language more regular than it actually is. An example is saying breaked instead of broken. See also overextension; overgeneralization.

oversampling

oversampling n. a sampling strategy in which certain subsets of participants are overrepresented in a study group compared to the larger population from which they are drawn. Oversampling involves deliberately selecting greater numbers of such participants than would be obtained via random sampling so as to enhance the accuracy of parameter values estimated through statistical procedures. For example, a researcher selecting firefighters from a candidate pool might include equal numbers of males and females to ensure a sufficient sample of females for statistical analysis, even though males comprise the majority of firefighters in the pool.

overshadowing

overshadowing n. in classical conditioning, a decrease in conditioning with one conditioned stimulus because of the presence of another conditioned stimulus. Usually a stronger stimulus will overshadow a weaker stimulus. —overshadow vb.

overshoot

overshoot n. the portion of an action potential that represents the stage when the membrane potential is transiently depolarized relative to the resting potential. Compare undershoot.

overshooting

overshooting n. in vision, the tendency for the saccades of the eyes to move to a position beyond that needed to fixate a target.

overstaffing

overstaffing n. a situation in which management judges that more people than necessary are being employed by an organization or one of its subunits. Compare understaffing. —overstaffed adj.

overt

overt adj. 1. denoting anything that is not hidden or that is directly observable, open to view, or publicly known. Compare covert. 2. deliberate or attracting attention.

overt behavior

overt behavior behavior that is explicit, that is, observable without instruments or expertise.

overt homosexuality

overt homosexuality gay or lesbian tendencies that are consciously recognized and expressed in sexual contact, in contrast to latent homosexuality.

overt integrity test

overt integrity test see integrity testing.

overt response

overt response any observable or external reaction, such as pointing to indicate one’s preference from among a set of objects or answering yes to a question. Compare covert response.

overtone

overtone n. see harmonic.

overtraining syndrome

overtraining syndrome in the context of sport or exercise, the unwanted physical and mental effects, collectively, of training beyond the individual’s capacities. Characteristic symptoms include decreased performance, increased ease of tiring, loss of motivation, emotional instability, inability to concentrate, and increased susceptibility to injury and infection. See burnout.

overvalued idea

overvalued idea a false or exaggerated belief that is maintained by an individual (e.g., the idea that one is indispensable in an organization). It is less rigidly and persistently held than a delusion, and its presence implies a nonconscious motivation that, if made conscious, would reduce its importance and corresponding dysfunctions.

overweight

overweight adj. the condition of having more body fat than is considered normal or healthy for an individual of a particular age, body type, or build. Overweight individuals may lie anywhere on a spectrum from mildly overweight to seriously overweight (see obesity; morbid obesity). One of the most frequently used standards for assessing the percentage of body fat is the body mass index.

oviduct

oviduct n. the tube in female animals through which egg cells from the ovary are conveyed to other parts of the reproductive system. In mammals, it is called the fallopian tube.

oviparity

oviparity n. reproduction in which fertilized eggs are laid and hatch outside the mother’s body. Compare viviparity. —oviparous adj.

OVLT

OVLT abbreviation for organum vasculosum of the lamina terminalis.

ovulation

ovulation n. the production of a mature secondary oocyte (see oogenesis) and its release from a graafian follicle at the surface of the ovary. Rupture of the follicle causes the oocyte to be discharged into a fallopian tube. See also ovum.

ovulatory cycle

ovulatory cycle the cyclical changes in the ovary associated with the development of a graafian follicle. See menstrual cycle.

ovum

ovum n. (pl. ova) a single female gamete that develops from a secondary oocyte following its release from the ovary at ovulation. Also called egg cell. See also oogenesis.

oxazepam

oxazepam n. a short-acting benzodiazepine that is the final active product of the metabolism of diazepam. Oxazepam possesses the advantage of having no metabolic products; it therefore has a predictable half-life and elimination time and requires minimal processing in the liver. Because of this, some consider it to be the preferred agent in the management of alcohol withdrawal. However, the need for close monitoring of dosing schedules leads others to prefer longer-acting agents for this condition. U.S. trade name: Serax.

oxidation

oxidation n. a chemical reaction in which a substance combines with oxygen or in which electrons are lost. In drug metabolism, oxidation is a common mechanism of Phase I metabolism, in which drugs are made more polar (i.e., more water soluble) by the addition of an oxygen atom, often via the action of cytochrome P450 enzymes.

oxycephaly

oxycephaly n. a high, pointed condition of the skull. Also called acrocephaly. —oxycephalic adj.

oxycodone

oxycodone n. see opioid analgesic.

oxytocic

oxytocic n. any of a group of drugs capable of stimulating contractions of the uterine muscles and used clinically to induce labor and elective or therapeutic abortion and to control postpartum bleeding. Oxytocics include ergot derivatives (e.g., ergonovine) and some prostaglandins.

oxytocin

oxytocin n. a peptide produced in the hypothalamus and released by the posterior pituitary gland into the blood, where it acts as a hormone, or into the central nervous system, where it acts as a neurotransmitter and binds to oxytocin receptors to influence behavior and physiology. Although perhaps best known for its role in stimulating contractions of smooth muscle in the wall of the uterus to facilitate labor and in the mammary glands to facilitate expression of milk—the so-called milk letdown reflex—oxytocin is present and serves important functions in both sexes. It has earned a reputation as a facilitator of social affiliation, and the tend-and-befriend response in particular, and it has been shown to influence sexual pleasure, reproductive functions, and parental behavior (especially maternal behavior). Additionally, research with nonhuman animals suggests that oxytocin—and the structurally similar compound vasopressin—is important for pair-bond formation, mate guarding, and recognition of social stimuli. A possible reason for the varied roles that oxytocin appears to play is that it has dual pathways and purposes. It has been theorized that when operating during times of low stress, oxytocin physiologically rewards, with feelings of well-being, those who maintain good social bonds. When operating during times of high stress or pain, however, it may produce physiological changes that encourage individuals to seek contact with others.

Psychology Terms Starting With 'O'