Neurocognitive characteristics of perceptual feedback processing differ in autism

Autistic individuals often show reduced adaptation to changing environmental demands, but the neurocognitive mechanisms underlying this difference remain unclear. We asked whether it may be explained by reduced sensitivity to external feedback and changes in task difficulty. Autistic and non-autistic adults of either sex, matched for cognitive ability, performed a pitch discrimination task in which their response was immediately followed by feedback. Accuracy was similar between the two groups, yet autistic participants exhibited a markedly reduced feedback-related negativity (FRN), an event-related EEG potential differentiating explicit negative versus positive feedback. They also showed weaker modulation of feedback-evoked EEG responses by perceptual difficulty. Lastly, they showed reduced trial-by-trial behavioral updating of perceptual bias following recent correct and easy trials. These effects were replicated in a follow-up experiment conducted 1-2 years later. When combined they classified autistic and non-autistic participants with about 80% accuracy. Together, our findings indicate that multiple processes for evaluating perceptual decisions and adjusting subsequent behavior differ in autism and likely contribute to slow updating in changing contexts.Significance Statement Autism is associated with reduced adaptation to changing environments in both behavior and neural signals, but the underlying neurocognitive mechanisms remain unclear. Here, we show that autistic individuals exhibit a reduced feedback-related negativity (FRN), an EEG component that is present when receiving negative instead of positive feedback. They also show weaker neural modulation by perceptual difficulty and reduced trial-by-trial behavioral updating of perceptual bias following recent correct and easy trials. These effects were replicated in a follow-up study. When combined, they classified autistic and non-autistic participants with high accuracy. These findings suggest that reduced flexibility in autism is associated with reduced processing of external feedback and task difficulty.