The mind's eye: Pupil size may be indicator of aphantasia

For most people, visual brain areas are also involved in mental imagery, thus resulting in pupil responses, especially when contrasting imagery of bright and dark things.”“However, for people with aphantasia, these areas may not be involved in imagery, or less so, resulting in an absent or reduced effect of mentally imagining bright and dark things on the pupil light response,” he added.The researchers also noted that pupil diameter may be encoded along with original visual information for bright objects and is thus replayed during memory decoding. “Here, a significant group difference is reported, but just over 60% of people with aphantasia show a pathological response to the pupillary test,” Dr. Sergio Della Sala, professor of human cognitive neuroscience at the University of Edinburgh, who was not involved in the study, told MNT. Dr. Joseph Johnson, professor of psychology at Miami University, Ohio, who was not involved in the study, told MNT that if these findings are reproduced in future studies, researchers and clinicians may be able to use the pupillary response to more objectively measure visual imagery than current self-reports.