REDUCED FLEXIBILITY IN PREDICTIVE TUNING AND CONTEXTUAL ADAPTATION IN AUTISM

In everyday environments, the brain generates predictions about upcoming stimuli and adjusts their certainty based on contextual probabilities. Given the well-documented resistance to change in autism, we hypothesized that autistic individuals may show reduced flexibility in modulating predictive certainty. To test this hypothesis, we recorded EEG from adolescents and young autistic adults (n = 20) and age- and IQ-matched non-autistic adults (n = 19) during a probabilistic cued target detection task in which cue validity varied across four levels (100%, 84%, 67%, and 33%). We examined two neural markers of anticipatory preparation, the contingent negative variation (CNV) and alpha event-related desynchronization (α-ERD), and a marker of cognitive updating, the P300 response to targets and invalid stimuli. Both groups showed preserved anticipatory activity, characterized by increased CNV amplitude and reduced alpha power prior to target onset. Across participants, lower pre-target alpha power was associated with larger CNV amplitudes, and larger CNV amplitudes predicted faster reaction times. Critically, anticipatory modulation by target probability was significantly reduced in the autistic group. Autistic participants also showed diminished P300 modulation to targets and invalid stimuli as a function of stimulus probability. Moreover, the relationship between anticipatory signals (CNV) and subsequent cognitive updating (P300), observed in non-autistic participants for target stimuli, was absent in the autistic group. Together, these findings suggest that while anticipatory mechanisms are present in autism, they are less flexibly adapted to contextual demands and are decoupled from later updating processes, which may contribute to resistance to change in autism.