Peritraumatic dissociation revisited: associations with autonomic activation, facial movements, staring, and intrusion formation

BACKGROUND

Peritraumatic dissociation is purported to emerge together with attenuated autonomic arousal, immobility, and staring. However, empirical evidence is scarce and heterogeneous. Moreover, it is still a matter of debate whether these responses predict intrusion formation.

OBJECTIVE

The present trauma-analogue study examined associations between peritraumatic dissociation, autonomic activation, facial movements, staring, and intrusion formation.

METHOD

Seventy-one healthy women watched a highly aversive film, while autonomic activation (heart rate, respiratory sinus arrhythmia, skin conductance level), facial movements (temporal variations in corrugator electromyography), and staring (fixation duration, tracklength) were assessed. Afterwards, participants rated the intensity of dissociation during film viewing and reported intrusions and associated distress in a smartphone application for 24 hours.

RESULTS

Peritraumatic dissociation was linked to higher autonomic arousal (higher heart rate and, on a trend-level, lower respiratory sinus arrhythmia), increased facial movements, and staring (lower tracklength). Peritraumatic dissociation, higher autonomic arousal (higher heart rate and lower respiratory sinus arrhythmia), staring (higher fixation duration), and, on a trend-level, more facial movements were linked to higher intrusion load (number x distress of intrusions) and together explained 59% of variance. Skin conductance level was neither linked to peritraumatic dissociation nor intrusion load.

CONCLUSIONS

Our results suggest that, at low-dissociation-levels observed in trauma-analogue studies, peritraumatic dissociation may occur together with heightened autonomic arousal and facial movements, indexing increased negative affect. Staring might, irrespectively of dissociation-levels, serve as objective marker for dissociation. Together, peritraumatic dissociation and its psychophysiological correlates might set the stage for later intrusion formation.

A multimodal examination of emotional responding to a trauma-relevant film among traumatic motor vehicle accident survivors

The Facial Action Coding System (Ekman & Friesen) has shown promise as a behavioral measure of emotional experience. The current study examined the degree of (de)synchrony between self-reported and facial expressions of fear, disgust, and sadness in response to a traumatic event-relevant film among individuals who had experienced a traumatic motor vehicle accident. Given high rates of comorbidity between posttraumatic stress symptoms (PTSS) and depressive symptoms, the potential impacts of both PTSS and depressive symptoms on emotional responding were examined. Results demonstrated synchrony between self-reported and facial expressions of disgust and sadness; however, no association between measures of fear was observed. Furthermore, depressive symptoms were associated with greater fear responding and PTSS were associated only with self-reported fear. Together, results support the importance of examining discrete negative emotions, rather than broad valence categories, when examining fear-based responding in traumatic event-exposed populations. Additional research examining the psychometric properties of the Facial Action Coding System as a measure of discrete emotional experiences among traumatic event-exposed individuals is needed to advance multimodal assessment approaches that yield incremental information for understanding emotional responding in this population.