Why don't you feel how I feel? Insight into the absence of empathy after severe traumatic brain injury.

Although the existence of empathy deficits in people with traumatic brain injury (TBI) is generally well accepted, it has been a topic of limited investigation. The current study examined the relationship between self-reported emotional and cognitive empathy and psychophysiological responding to emotionally evocative pictures in 20 patients with severe TBI and 22 control participants. Eighteen pictures with alternating pleasant, unpleasant and neutral content selected from the International Affective Picture System (IAPS) were presented whilst facial muscle responses, skin conductance, and valence and arousal ratings were measured. Self-reported emotional and cognitive empathy questionnaires were also administered. In comparison to control participants, those in the TBI group displayed a reduction in the ability to empathize both emotionally and cognitively, and evidence that these two aspects of empathy may be interconnected was established. Further, TBI participants showed reduced facial responding to unpleasant pictures, while also rating them as less unpleasant and arousing than controls. In addition, they exhibited lowered autonomic arousal to all pictures, regardless of affective valence. Interestingly, hypoarousal to pleasant pictures in particular was found to be related to the absence of empathy observed after TBI, and is consistent with the view that impaired emotional responsivity is associated with impairment to the empathy network. The results represent a further step towards understanding what processes shape empathy.