Eye tracking as a tool for assessing social cognition: A case-control study comparing patients with psychosis and healthy controls

Abstract

Background: Eye movement dysfunction is a common abnormality in Schizophrenia and other psychotic disorders. Various eye movement paradigms can be used to measure predefined parameters using eye trackers. The current study intends to understand the eye movement characteristics in individuals suffering from psychosis using newer eye-tracking instruments with better precision. Methodology: In this study, we included 29 individuals meeting the diagnostic criteria for schizophrenia spectrum and other psychotic disorders based on the clinical assessment as per Diagnostic and Statistical Manual of Mental Disorders, 5th Edition along with 29 age- and gender-matched healthy controls and measured various eye tracking parameters using a Tobii Pro Spectrum. We compared the eye-tracking parameters between both groups. Results: There were significant differences between the groups in the free-viewing task. The average duration of fixations was higher, whereas the number of fixations and total amplitude of saccades was found to be reduced in the patient group. The peak velocity of the first saccade was also seen to be reduced in the patient group. However, there were no abnormalities in the anti-saccade, predictive saccade, memory saccade, and smooth pursuit tasks. Eye movement parameters were also found to be significantly correlated with the cognitive task measurements. Conclusion: These findings confirm the presence of eye movement abnormalities in psychosis spectrum disorders and their role in cognitive deficits in psychosis. Altered free viewing may be linked to deficits in social cognition found in patients with schizophrenia.