Metacognitive and noradrenergic differences in autistic adults

People with autism spectrum disorder (ASD) experience the world differently, but the neurocognitive mechanisms that underlie these differences are poorly understood. In neurotypical (NT) adults, everyday perceptions are accompanied a sense of reliability, or confidence, which promotes flexible learning and adaptive behaviour. One novel hypothesis is that perception is not compromised in ASD per se, but rather the ability to identify the fidelity of one’s own perception; i.e. metacognition. To test this, we measured perceptual metacognitive efficiency in adults with and without ASD using a visual discrimination task in combination with hierarchical decision theoretic modelling. Our results reveal that adults with ASD exhibit reduced correspondence between accuracy and confidence in perception, despite equivalent task performance. We then demonstrate that the relationship between confidence and pupil dilation (a proxy for noradrenergic function) shows reduced dynamic range in autism; diminished response pre-perceptually, and enhanced response post-perceptually. Our results offer empirical support for previously hypothesised, but never tested, metacognitive and noradrenergic alterations in ASD, offering mechanistic insights into the non-social features of the condition.