Eye tracking and physiological reactivity to threatening stimuli in posttraumatic stress disorder.

This study tested the vigilance-avoidance model of anxiety and attention bias in posttraumatic stress disorder (PTSD). This study used eye tracking technology to record initial fixations, pupil dilation, fixation time and concurrent skin conductance response to examine initial orienting towards threat stimuli and subsequent fixations. Twenty-one traumatized participants (11 diagnosed with PTSD and 10 trauma-exposed participants without PTSD) viewed 32 stimuli (with four words in each quadrant). Sixteen trials contained a trauma-relevant word in one quadrant and 16 had four neutral words. PTSD patients reported significantly greater number of initial fixations to trauma words, and a greater number of skin conductance responses to initial threat fixations. There were no significant differences in subsequent fixations to trauma words between groups. Although this study provides evidence of attentional bias towards threat that is accompanied by specific autonomic arousal, it does not indicate subsequent avoidance of threat stimuli in PTSD.