Neural mechanisms of empathy in adolescents with autism spectrum disorder and their fathers.

A deficit in empathy has been repeatedly described in individuals with autism spectrum disorder (ASD) and also, albeit less markedly, in their unaffected relatives. Here, we aimed to investigate the neural mechanisms of empathy in ASD, and to explore familial contributions to empathy correlates. Using functional magnetic resonance imaging, 15 boys with ASD, 11 fathers of adolescents with ASD, and two control groups comparable for age and IQ (n=15 typically developing boys and their fathers (n=9)) were investigated during an empathy task. Emotional faces were presented and participants were either asked to infer the emotional state from the face (other-task) or to judge their own emotional response to the face (self-task). When attributing emotions to self and other, the ASD group showed diminished fusiform gyrus activation compared to controls. Neural activity in the fusiform gyrus was inversely related to social deficits in ASD subjects. Moreover, when ASD subjects inferred their own emotional response to faces, they showed less congruent reactions and inferior frontal gyrus activity was decreased. Although fathers of ASD children scored higher on a self-rating scale for autistic symptoms compared to control fathers, their task performance was unimpaired. However, neurally, fathers of affected children also showed reduced fusiform gyrus activation when inferring others' emotions. Shared abnormalities in fusiform gyrus activation in affected adolescents and first-degree relatives suggest that this dysfunction constitutes a fundamental deviation in ASD. Moreover, the findings provide evidence that both aberrant neural face and mirroring mechanisms are implicated in empathy impairments in ASD.