The Pupillary Response in Cognitive Psychophysiology and Schizophrenia a

The human pupillary response, whose final neural pathways are mediated through the autonomic nervous system, has been shown to reflect more centrally occurring processes when examined from the perspective of information processing activities. This paper will examine components of information processing as reflected in the pupillary response, and its relation to other neurophysiological signs of cognitive activity, most notably, event-related brain potentials. Both the constriction of the pupil to light (miosis), as well as the dilation (dilatation; mydriasis) resulting from information delivery, have provided useful adjuncts in the study of psychopathology, especially with reference to schizophrenia. The time course of pupillary dilation, reflected in the morphology of the pupillographic record, indicates a high degree of similarity among related family members. Findings from psychiatric patients and their relatives will be reviewed. While the contributions of separate physiological components to the pupillary dilation response that relate to cognitive activity have never been adequately delineated, a review of findings indicates the possibility for experimental dissection of components. A model delineating likely psychophysiological contributions to the pupillary response, and approaches for testing the model, will be presented.