Lack of empathy following traumatic brain injury associated with reduced responsiveness to anger

A new study has recently revealed evidence of a relationship between physiological responses to anger and a reduction of emotional empathy post-injury, as reported in the May 2011 issue of Elsevier's Cortex.

Researchers from the University of New South Wales, Australia, teamed up to investigate whether physiological responses to emotions correlate with emotional empathy in a group of adults with severe TBI and a group of healthy control participants. After determining the emotional empathy abilities of the participants by questionnaire, the researchers measured activation of their facial muscles and sweat glands, in response to happy and angry facial expressions, using facial electromyography (EMG) and skin conductance. They found that the control group spontaneously mimicked the emotional facial expressions they saw, and also perspired more in response to angry faces. In contrast, those in the TBI group generally scored lower in emotional empathy and were less responsive, specifically to angry faces. Lack of emotional empathy was specifically found to be associated with reduced physiological responses to angry faces.

"The results of this study were the first to reveal that reduced emotional responsiveness observed after severe TBI is linked to changes in empathy in this population. The study also lends support to the conclusion that impaired emotional responsiveness -- including facial mimicry and skin conductance -- may be caused, at least in part, by dysfunction within the system responsible for emotional empathy," explains author Arielle De Sousa. "This has important implications for understanding the impaired social functioning and poor quality of interpersonal relationships commonly seen as a consequence of TBI, and may be key to comprehending and treating empathy deficits post-injury."