Investigation of the Relationship Between Orientation Discrimination Thresholds, Autistic, and Schizotypal Personality Traits

Imbalances in cortical excitation and inhibition (E-I) have been implicated in both autism spectrum conditions (ASC) and schizophrenia spectrum conditions (SSC). However, most studies investigate these clinical conditions independently, possibly due to the difficulty of obtaining comorbid clinical populations. As such, the current study investigated the relationship between performance in the orientation discrimination task "ODT" as a potential proxy for E-I balance and the autistic (as assessed by Autism Spectrum Quotient "AQ") and schizotypal personality traits (as assessed by Schizotypal Personality Questionnaire-Brief "SPQ-BR") in the general population. 87 healthy adult volunteers participated in the study. We found that high autistic personality traits are associated with enhanced performance in the oblique condition of ODT. In contrast, high schizotypal personality traits are associated with poor performance in the vertical condition of ODT. Such associations support the suggested disruption of cortical E-I balance in ASC and SSC.