dysfunctions associated with sleep, sleep stages, or partial arousals

one of four basic types of sleep disorders, differentiated from the other types by the presence of physiological activations at inappropriate times during sleep rather than by abnormalities in the mechanisms involved in the timing of sleep and wakefulness. This type of sleep disorder includes nightmare disorder, sleep terror disorder, and sleepwalking disorder; in DSM–IV–TR and DSM–5, these are classified as parasomnias.

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Psychology term of the day

February 23rd 2025

perceptual organizational deficit

a phenomenon in which a subset of people with schizophrenia have particular difficulty visually integrating the parts of an object and seeing them as an ensemble. For example, if looking at a watch, they will perceive the hands, the dial, and the numbers as separate forms but will have difficulty processing the watch face as a whole. [coined by U.S. psychologist Steven M. Silverstein (1962– )]