Autistic traits relate to reduced reward sensitivity in learning from point-light displays (PLDs)

A number of studies have linked autistic traits to difficulties in learning from social (versus non-social) stimuli. However, these stimuli are often difficult to match on low-level visual properties, which is especially important given the impact of autistic traits on sensory processing. Additionally, studies often fail to account for dissociable aspects of the learning process in the specification of model parameters (learning rates and reward sensitivity). Here, we investigate whether learning deficits in individuals with high autistic traits exhibit deficits when learning from facial point-light displays (PLDs) depicting emotional expressions. Social and non-social stimuli were created from random arrangements of the same number of point-lights and carefully matched on low-level visual properties. Neurotypical participants (N = 63) were assessed using the autism spectrum quotient (AQ) and completed a total of 96 trials in a reinforcement learning task. Although linear multi-level modelling did not indicate learning deficits, pre-registered computational modelling using a Rescorla-Wagner framework revealed that higher autistic traits were associated with reduced reward sensitivity in the win domain, demonstrating an attenuated response to received feedback during learning. These findings suggest that autistic traits can significantly impact learning from PLD feedback beyond a general deficit in learning rates.