Extraversion is associated with lower cardiovascular reactivity to acute psychological stress

The relationship between personality traits and health-related quality of life after mild-to-moderate traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) causes major societal burden and may negatively influence an individual's health-related quality of life (HRQoL). Personality factors have been linked to persistent post-concussion symptoms (PPCS), and PPCS have been found to affect HRQoL. However, there is a knowledge gap concerning the association between personality traits and HRQoL after mild-to-moderate TBI. Thus, this study aims to investigate the association between personality traits and HRQoL in patients with mild-to-moderate TBI at 15 months post-injury, while controlling for socio-demographic characteristics, injury-related factors and symptom burden.

METHODS

Data from 86 participants with mild- to-moderate TBI from a previous randomised controlled trial were analysed. Sociodemographic, injury-related and psychological factors were recorded 2-3 months post-injury. Personality traits were measured at 15 months post-injury with The NEO Five-factor Inventory-3. The Quality of Life after Brain Injury- Overall Scale (QOLIBRI-OS) and the EuroQol-visual analogue scale (EQ-VAS) were used to measure HRQoL at 15 months post-injury. Two separate multiple linear regression models were performed for the outcome variables; QOLIBRI-OS (model 1) and EQ-VAS (model 2).

RESULTS

The factors associated with lower HRQoL were more severe PPCS, higher levels of the personality traits neuroticism and conscientiousness (model 1), female sex and being single/living alone (model 2). Higher levels of the personality trait extraversion were associated with higher HRQoL in both models.

CONCLUSION

The results highlight how non-injury factors may be associated with recovery and HRQoL after TBI. Considering personality factors may be helpful when identifying individual risk and protective factors for outcomes after mild-to-moderate TBI.

Extraversion and the Brain: A Coordinate-Based Meta-Analysis of Functional Brain Imaging Studies on Positive Affect

OBJECTIVE

Extraversion is a fundamental personality dimension that contributes to an individual's overall health and well-being. Many studies have examined the neural bases of extraversion but these results are inconsistent. This study adopted a meta-analysis approach to examine the brain activity correlates of extraversion by incorporating functional neuroimaging studies in the context of positive affect/emotional stimuli.

METHODS

A systematic literature search was performed in the databases of PubMed, Web of Science Core Collection, Embase, PsycInfo, CNKI, WanFang, and Weipu. The demographic characteristics and basic information of the included studies were first summarized. Then, a meta-analysis was conducted using anisotropic effect-size seed-based d mapping. Jackknife sensitivity analysis was next conducted to examine the reliability of the findings. Finally, meta-regression analysis was performed to test the potential demographic effects (i.e., sex and age) on the association between extraversion and brain activity.

RESULTS

A total of 11 studies were included in the meta-analysis. The results of meta-analysis revealed robust and consistent positive correlations between extraversion and activation of right inferior frontal gyrus/insula, right angular gyrus, and left precentral gyrus during positive affect processing. In contrast, brain activity in the right striatum during positive affect processing was negatively associated with extraversion. Additionally, meta-regression analysis revealed sex as a moderator in the relationship between extraversion and right insular activation.

CONCLUSIONS

Overall, our study is the first to provide a comprehensive understanding of functional brain activation patterns of extraversion, which may be helpful for targeting of specific brain regions in personalized interventions for extraversion-related psychological/physical illness.

Loneliness mediates the association between trait social anxiety and cardiovascular reactivity to acute psychological stress

The primary aims of the current study are (1) to examine the association between trait social anxiety and cardiovascular reactivity to acute psychological stress, and (2) to identify if loneliness significantly mediates the association between trait social anxiety and cardiovascular reactivity. A sample of 658 participants completed a cardiovascular reactivity protocol consisting of a resting baseline and stressor phase (mental arithmetic and Stroop), with systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) monitored throughout. Participants also completed self-reported measures assessing social anxiety and loneliness. Social anxiety was associated with increased self-reported stress. However, no significant associations between social anxiety and measures of cardiovascular reactivity were observed in regression analyses. Loneliness was significantly associated with lower SBP and DBP reactivity. Additionally, loneliness significantly mediated the association between trait social anxiety and both SBP reactivity and DBP reactivity. Here, trait social anxiety predicted greater levels of loneliness, which in turn was associated with diminished cardiovascular reactivity. No significant associations emerged for HR reactivity. These blunted blood pressure responses to acute stress may indicate a potential mechanism leading to adverse prospective health outcomes.

How is variability in physiological responses to social stress related to punishment and reward sensitivities? Preliminary findings from the revised reinforcement sensitivity theory of personality perspective

OBJECTIVE

Although personality traits are assumed to have biological/physiological foundations, research has yielded mixed evidence regarding the relationship between personality and physiological stress responses. Moreover, the field has often overlooked the contemporary neuroscience-based personality approach, known as the Reinforcement Sensitivity Theory (RST) of Personality, in stress research.

METHOD

The present study examined the relationship between the revised RST's personality dimensions and heart rate and skin conductance level (SCL) in response to the Trier Social Stress Test in a sample of 61 healthy university students.

RESULTS

Piecewise latent growth curve analysis controlling for the participants' current life stress, smoking use, and caffeine intake revealed that individuals with higher behavioral inhibition exhibited higher physiological reactivity, whereas those with high reward sensitivity showed smaller heart rate reactivity. The behavioral disengagement facet of the behavioral inhibition scale was associated with reduced sympathetic arousal during the stress task. Additionally, reward interest was associated with a larger recovery of SCL.

CONCLUSION

Results were generally in line with the revised theory. The study findings were discussed within the paradigm of the approach-avoidance conflict and highlighted the importance of reward sensitivity in stress resilience.

Physiological reactivity and habituation to acute psychological stress: The influence of trait extraversion

BACKGROUND AND AIMS

Adaptive physiological responses to stress have been suggested as a potential mechanism facilitating the association between extraversion and positive health outcomes. The present study examined the influence of extraversion on physiological reactivity and habituation to a standardized psychological stress task presented as two separate laboratory sessions approximately 48 days apart.

METHODS

The present study utilized data from the Pittsburgh Cold Study 3. Participants in the study (N = 213, mean age = 30.13, SD = 10.85 years; female = 42.3 %) completed a standardized stress testing protocol twice, at two separate laboratory sessions. The stress protocol consisted of a speech preparation period (5-minutes), a public specking task (5-minutes), and a mental arithmetic task with observation (5-minutes). Trait extraversion was assessed using 10-items from the international personality item pool (IPIP). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and salivary cortisol (SC) were assessed throughout a baseline phase and the stress task phase.

RESULTS

Extraversion was statistically significantly associated with larger DBP and HR reactivity in response to the initial stress exposure, as well as greater habituation of DBP, MAP and HR on repeated stress exposure. No statistically significant associations emerged between extraversion and SBP responses, SC responses or self-reported state affective responses.

CONCLUSION

Extraversion is associated with greater cardiovascular reactivity, as well as pronounced cardiovascular habituation to acute social stress. These findings may indicate an adaptive response pattern amongst highly extraverted individuals and a potential mechanism leading to positive health outcomes.