Suboptimal but intact integration of reward information during perceptual decision-making in autism

Alterations in reward processing have been proposed as a contributing factor to social and communication symptoms in autism. However, the nature of these alterations remains unclear, and it is debated whether autism is characterized by reduced sensitivity to reward. Evidence for general reduced reward processing in autism primarily comes from neurobiological studies, yet it remains uncertain how these findings translate to autistic behavior. A key challenge in addressing this question lies in the quantitative assessment of behavioral responses to reward. Here, we addressed this issue by investigating the integration of monetary reward information into behavior through the framework of Bayesian perceptual decision-making, enabling a quantitative evaluation of the direct contribution of reward to decision-making. Autistic (n = 32) and non-autistic (n = 48) participants performed an orientation categorization task, while the monetary reward given per correct answer varied across categories. Using signal-detection theory, we estimated decision boundaries while accounting for sensory uncertainty and prior expectation. Both groups comprehended the reward contingencies similarly and showed comparable perceptual sensitivity. Importantly, autistic individuals adjusted their decision boundaries in response to monetary reward in a suboptimal yet similar manner to that of non-autistic individuals. Integration of monetary reward during perceptual decision-making is intact in autism. These findings challenge the view of general reduced reward processing in autism and are inconsistent with accounts proposing enhanced rationality in autism.