Ostracism and physiological arousal following traumatic brain injury

Disinhibition, rather than moderate-to-severe traumatic brain injury, moderates the impact of anger provocation on subjective emotional experience

OBJECTIVE

Altered reactivity to emotional stimuli is common after traumatic brain injury (TBI), which is suggested to reflect difficulties with emotion regulation. While disinhibition is common after moderate-to-severe TBI, limited research has investigated the link between disinhibition and emotional reactivity in this clinical group. The aim of this research, therefore, was to investigate the relationship between disinhibition and TBI to anger provocation.

METHOD

Thirty-five individuals with moderate-to-severe TBI and thirty-one controls completed an anger induction task. Participants rated their experience of emotions and subjective arousal before and after the induction. Heart rate, respiration and skin conductance were also measured. Disinhibition was measured using the Frontal Systems Behavior Scale.

RESULTS

In the full sample, the mood induction led to increased skin conductance, respiration, and self-reported anger, tension, arousal and negative mood. There were no differences between those with TBI and controls. Disinhibition interacted with the impact of anger provocation on subjective, but not objective, outcomes such that those elevated in disinhibition reported increased feelings of anger and tension in response to the mood induction. Disinhibition did not interact with TBI across any subjective and objective emotional measures examined in response to mood induction.

CONCLUSIONS

While anger causes emotional changes for all individuals, these changes are particularly pronounced among those who are disinhibited, irrespective of whether an individual has sustained a TBI. This is an important consideration when examining emotional regulation post-TBI as the degree of disinhibition appears to alter subjective interpretations of emotional events, which could lead to emotion dysregulation.

Impairments in Physiological Reactivity to Emotive Stimuli After Traumatic Brain Injury: A Systematic Review of Skin Conductance and Heart Rate Variability Evidence

OBJECTIVE

To examine evidence of impairments in physiological reactivity to emotive stimuli following traumatic brain injury (TBI).

METHODS

A search of PsychINFO, CINAHL (Cumulative Index to Allied Health Literature), Web of Science, EMBASE (Excerpta Medica dataBASE), and Scopus databases was conducted from 1991 to June 24, 2021, for studies comparing changes in skin conductance or heart rate variability to emotive stimuli between adults with TBI and controls. Two reviewers independently assessed eligibility and rated methodological quality.

RESULTS

Twelve eligible studies examined physiological reactivity to laboratory-based emotive stimuli, which included nonpersonal pictures/videos, posed emotion, stressful events, and personal event recall. Overall, 9 reported evidence that individuals with TBI experience lower physiological reactivity to emotive stimuli compared with healthy controls, although the findings varied according to the type and valence of emotional stimuli and physiological parameter. Most studies using nonpersonal pictures or videos found evidence of lower physiological reactivity in TBI participants compared with controls.

CONCLUSIONS

Based on laboratory-based studies, individuals with TBI may experience lower physiological reactivity to emotive stimuli. Further research is needed to investigate physiological responses to personally relevant emotional stimuli in real-world settings and to understand the interplay between physiological reactivity, subjective experiences, and behavior.

Physiological reactivity at rest and in response to social or emotional stimuli after a traumatic brain injury: A systematic review

Numerous studies have shown that alterations in physiological reactivity (PR) after traumatic brain injury (TBI) are possibly associated with emotional deficits. We conducted a systematic review of these studies that evaluated PR in adults with moderate-to-severe TBI, either at rest or in response to emotional, stressful, or social stimuli. We focused on the most common measures of physiological response, including heart rate (HR), heart rate variability (HRV), respiratory sinus arrhythmia (RSA), electrodermal activity (EDA), salivary cortisol, facial electromyography (EMG), and blink reflex.

Methods

A systematic literature search was conducted across six databases (PsycINFO, Psycarticles, SciencDirect, Cochrane Library, PubMed, and Scopus). The search returned 286 articles and 18 studies met the inclusion criteria.

Results

Discrepancies were observed according to the type of physiological measure. Reduced physiological responses in patients with TBI have been reported in most EDA studies, which were also overrepresented in the review. In terms of facial EMG, patients with TBI appear to exhibit reduced activity of the corrugator muscle and diminished blink reflex, while in most studies, zygomaticus contraction did not show significant differences between TBI and controls. Interestingly, most studies measuring cardiac activity did not find significant differences between TBI and controls. Finally, one study measured salivary cortisol levels and reported no difference between patients with TBI and controls.

Conclusion

Although disturbed EDA responses were frequently reported in patients with TBI, other measures did not consistently indicate an impairment in PR. These discrepancies could be due to the lesion pattern resulting from TBI, which could affect the PR to aversive stimuli. In addition, methodological differences concerning the measurements and their standardization as well as the characteristics of the patients may also be involved in these discrepancies. We propose methodological recommendations for the use of multiple and simultaneous PR measurements and standardization. Future research should converge toward a common methodology in terms of physiological data analysis to improve inter-study comparisons.