Pupillometry in the Assessment of Psychoemotional State and Cognitive Functions in Humans

Pupillometry is an investigation method yielding quantitative assessment of pupil diameter. Pupil size is regulated by structures of the autonomic nervous system (the oculomotor nerve nuclei, the ciliospinal center) and is associated with the level of illumination. However, overlying brain structures, in particular the cortex, acting via the locus coeruleus, pretectal olivary nuclei, and superior colliculi, have modulating effects on pupil reactions which are not related to illumination. Initial pupil diameter and changes in diameter associated with the performance of certain tasks can be used for objective assessment of subjects’ psychoemotional state and cognitive functions. There is evidence of changes in pupil reactions in autism spectrum disorders and depression, as well as in Alzheimer’s disease, Parkinson’s disease, and other organic brain diseases. Further research into pupillometry techniques is needed to identify new areas of application.