Using Startle to Objectively Measure Anger and Other Emotional Responses After Traumatic Brain Injury

Abstract

To determine the effectiveness of a modulated acoustic startle reflex paradigm with emotional imagery in studying physiological changes associated with emotional responses in persons with traumatic brain injury (TBI). Outpatient rehabilitation hospital. Six individuals with moderate to severe TBI. Mean age was 32 years and mean years postinjury were 9.9. The modulated acoustic startle reflex procedure involved imagery of emotional scripts (joy, anger, fear, and neutral) followed by a startle noise, versus startle noise alone (no script). Eyeblink and skin conductance response, subjective arousal and valence ratings of the scripts, and general anger questionnaire. Startle blink responses following anger imagery were significantly smaller than those following fear (P = .006) and neutral (P = .023) imagery. Skin conductance response did not change significantly based on the content of the scripts (P = .070). Large startle blink responses indicate avoidance of a stimulus. Our findings suggest that participants with TBI did not have an avoidant reaction to anger-inducing stimuli. Skin conductance response findings may imply arousal impairments. The modulated acoustic startle reflex was effective in measuring emotional responses; however, larger studies comparing persons with TBI with control groups are needed to further explore these findings.