Empathic arousal and social understanding in individuals with autism: evidence from fMRI and ERP measurements.

Lack of empathy is a hallmark of social impairments in individuals with autism spectrum disorder (ASD). However, the concept empathy encompasses several socio-emotional and behavioral components underpinned by interacting brain circuits. This study examined empathic arousal and social understanding in individuals with ASD and matched controls by combining pressure pain thresholds (PPT) with functional magnetic resonance imaging (study 1) and electroencephalography/event-related potentials and eye-tracking responses (study 2) to empathy-eliciting stimuli depicting physical bodily injuries. Results indicate that participants with ASD had lower PPT than controls. When viewing body parts being accidentally injured, increased hemodynamic responses in the somatosensory cortex (SI/SII) but decreased responses in the anterior mid-cingulate and anterior insula as well as heightened N2 but preserved late-positive potentials (LPP) were detected in ASD participants. When viewing a person intentionally hurting another, decreased hemodynamic responses in the medial prefrontal cortex and reduced LPP were observed in the ASD group. PPT was a mediator for the SI/SII response in predicting subjective unpleasantness ratings to others' pain. Both ASD and control groups had comparable mu suppression, indicative of typical sensorimotor resonance. The findings demonstrate that, in addition to reduced pain thresholds, individuals with ASD exhibit heightened empathic arousal but impaired social understanding when perceiving others' distress.