“…Specifically, the physiological evidence from TBI studies points to muted skin conductance, reduced eyeblink startle and facial EMG (electromyography) responses (Blair and Cipolotti, 2000;de Sousa et al, 2012de Sousa et al, , 2011de Sousa et al, , 2010Hopkins et al, 2002;McDonald et al, 2011;Sanchez-Navarro et al, 2005;Saunders et al, 2006) to aversive stimuli in particular, including angry facial expressions, distressing film clips, and unpleasant pictures (e.g., IAPS; Sanchez-Navarro et al, 2005). Deficits in psychophysiological responding to aversive stimuli in severe TBI are reflected in lower self-reported levels of arousal (e.g., Saunders et al, 2006) and valence (de Sousa et al, 2010). TBI adults who self-report low empathy levels also exhibit reduced facial muscle responding to both pleasant and unpleasant stimuli, as well as lower autonomic arousal (i.e., skin conductance, de Sousa et al, 2012).…”