Intermediating the Effect of Inter-Stimuli Interval in Repetition Suppression of Face Images among Adults with High and Low Levels of Autistic-Like Traits

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder, characterized by pervasive symptoms, as in DSM-V. It is identified and associated with a number of atypicalities, including difficulties in face memory, centralized interest, and abnormal body movements. Individuals high in ASD show problems in face processing, gaze, and expression that arise from inappropriate brain functioning in social behaviors and communication skills. When a sensory stimulus is repeated, the excited neural signal is always smaller than its first observation. This phenomenon has been observed for many sensory states and stimuli using different methods. The present study was conducted to investigate the repression of facial image reproduction with the mediating role of time in adults with low and high autism-like traits. This research was carried out with a quantitative method approach in the form of a descriptive design in two groups with low and high ASD. For this purpose, the autism spectrum quotient, cognitive task for suppressing repetitive face images, and EEG were used. The sample consisted of 30 male undergraduate and postgraduate students aged between 18 and 35. As a result, the research findings showed a significant statistical difference between the two groups with low and high ASD in terms of cognitive and EEG correlates in suppressing the repetition of facial images. Specifically, an interactive effect of time (short or long intervals), consistency of stimuli (repeated or not), and autism spectrum (high or low) was significant (F1, 28 = 4.53, p = 0.04). This was indexed by a lack of N2 and P3 in those with high compared to low ASD. The possible insensitivities to repetition might be due to unused extra neural resources in high ASD, close to brain areas involved in face processing.