Effect of level of autistic traits on motion inspection time performance in centre-surround suppression tasks

The mechanisms underlying visual anomalies observed in individuals with Autism Spectrum Disorder (ASD), presenting in the form of impaired global visual perception and enhanced local perception have long been debated. Researchers have sought to investigate the phenomenon of surround suppression, the inhibitory mechanism responsible for filtering visual noise in high contrast stimuli of increasing size. Mixed results have shown impaired gain control reduces surround suppression allowing for improved motion inspection in certain conditions, along with the possibility that receptive field size and population varies among the ASD population producing size-specific alteration in motion inspection. The present study aims to investigate whether the level of autistic traits predicts motion inspection time performance in a random dot kinetogram (RDK), a function of stimulus size and contrast. A total of 12 typically developing (TD) participants were screened and grouped by AQ score to indicate level of autistic traits (low, medium and high). Results revealed that the high AQ groups motion inspection time significantly outperformed the mid AQ group for small and large central RDK of low contrast. This result suggests an interaction between temporal and spatial processing may have masked the effects of gain control and impaired surround suppression in higher contrast conditions, often seen in previous studies.