Reduced monitoring of task performance is an effective biomarker of autism

People continuously track and adjust their behavior using external and internal signals. Autistic individuals manifest reduced sensorimotor error correction and slower updating of perceptual priors, yielding reduced behavioral flexibility. A potential reason for this reduced flexibility is a lessened sensitivity to both external and internal feedback. A key brain region involved in online monitoring of behavior and updating world models, known to be atypically activated in autism spectrum disorder (ASD), is the anterior cingulate cortex (ACC). During a two-tone pitch discrimination task, we used EEG to track ASD participants' ACC response dynamics, as manifested in their feedback-related negativity (FRN) component produced following "incorrect" feedback. We found that the FRN is missing in more than half of the ASD (17/30) participants, while clearly present in almost all non-autistics (33/35). Moreover, only in non-autistics, feedback affected performance in the following trial. Their responses were slower following an erred trial, their accuracy was improved following hard and correct trials, and they were more affected by the perceptual priors following easy and correct trials. Non-autistics' EEG response to feedback was also sensitive to trial difficulty, while the EEG response of ASD participants was not. Overall, we observed EEG and behavioral correlates of reduced sensitivity to both external and internal feedback in ASD. These observations suggest that increasing the salience of the external feedback could improve ASDs' error monitoring and perhaps increase their behavioral flexibility.