any one of a limited set of emotions that typically are manifested and recognized universally across cultures. The list of primary emotions varies across different theorists. They often include fear, anger, joy, sadness, disgust, contempt, and surprise; some theorists also include shame, shyness, and guilt. Also called basic emotion; core emotion. Compare secondary emotion.
skewed perceptual experience. Examples include the distorted images produced by dreams or hallucinogenic drugs, geometric illusions (e.g., the Müller-Lyer illusion), visions occurring in states of sensory deprivation or dehydration, and distortions produced by modifying auditory stimuli. Perceptual distortion may also occur as a consequence of acquired brain injury. See also metamorphopsia.