Autism, Personality Pathology, and the Neural Response to Rewards

The autism social motivation hypothesis suggests that diminished reward value of social stimuli contributes to deficits in social motivation. Research indicates that autistic individuals show decreased neural responding to both social and non-social reward, suggesting domain-general reward system differences. However, autism is heterogenous with extensive co-occurring psychopathology, and the autism phenotype may not be the best way to understand its relationship with neural reward response. Autism has been associated with normative and pathological personality domains that may better represent the heterogeneity and comorbidity of autism. The present study examined associations between autism traits, pathological personality, and the neural response to multiple reward types. The sample included 18-33-year-old undergraduates who completed monetary, social, and restricted interests reward tasks while we recorded electroencephalography to measure the reward positivity (RewP), an event-related potential indicator of reward sensitivity. Participants completed self-report measures of autism traits and the pathological personality traits negative emotionality, detachment, and anankastia. Autism traits were not directly related to the RewP but were positively associated with pathological personality dimensions. Across all reward tasks, negative emotionality was related to a larger RewP while detachment and anankastia were related to a smaller RewP. All three pathological personality dimensions mediated the relationship between autism traits and the RewP. The present study suggests that autism and neural reward response is at least partially mediated by comorbid psychopathology. Moreover, the results are inconsistent with the social motivation hypothesis and instead suggest that autism is linked to domain-general neural response to rewards.