Subjective emotional experience and physiological responsivity to posed emotions in people with traumatic brain injury

Objective: Although the presence of empathy deficits following traumatic brain injury (TBI) is well established, there is a paucity of research investigating the underpinning mechanisms. This study investigated whether feedback from posed emotional expressions and psychophysiological responsivity, thought to play a role in emotional empathy, are impaired after TBI. Method: Thirty adults with TBI and 30 demographically matched healthy controls completed 2 feedback tasks while skin conductance and heart rate were recorded. In Feedback Task 1, participants assumed different emotional postures and rated how this made them feel. In Feedback Task 2, participants held a smile or frown while viewing neutral images and rated the pleasantness of each image. Results: Participants with TBI did not differ from controls in their subjective ratings in response to posed emotional expressions. However, we found reduced skin conductance responses to rapid facial manipulations and some evidence of altered physiological arousal to sad emotional postures in participants with TBI. Finally, there was no relationship between emotional empathy and facial feedback or physiological responsivity. Conclusions: We failed to replicate past research that demonstrated an impairment in the feedback effect in people with TBI. These normal subjective responses, though, were in the context of reduced psychophysiological responding to the posed expressions, suggesting that another mechanism can contribute to normal feedback effects after TBI. Finally, we did not find the expected relationship between the feedback effect and emotional empathy but may have been limited by the lower than expected rates of low emotional empathy in our sample.