Pupil Size Changing by Pattern Brightness and Pattern Contents

Abstract

Pupil size is well known to change in response to brightness and mental activities, but the correlation between these two reactions is unclear.
First, pupullary changes were measured at various brightnesses, with and without audio instructions which stimulate mental activities. ANOVA found that there is no interaction between pupillary changes due to brightness effects and mental activities.
Second, patterns were presented to subjects at various brightnesses after initially being presented at a constant brightness.
The correction function is obtained that controls pupil size according to the brightness level. Subject interest in each pattern is evaluated from the pupillary changes as corrected by this function.