The present study examined the relationship between personality traits and the response to acute psychological stress induced by a standardized laboratory stress induction procedure (the Trier Social Stress Test, TSST). The stress response was measured with a combination of cardiovascular reactivity, hypothalamic–pituitary–adrenal axis reactivity, and subjective affect (including positive affect, negative affect and subjective controllability) in healthy individuals. The Generalized Estimating Equations (GEE) approach was applied to account for the relationship between personality traits and stress responses. Results suggested that higher neuroticism predicted lower heart rate stress reactivity, lower cortisol stress response, more decline of positive affect and lower subjective controllability. Individuals higher in extraversion showed smaller cortisol activation to stress and less increase of negative affect. In addition, higher openness score was associated with lower cortisol stress response. These findings elucidate that neuroticism, extraversion and openness are important variables associated with the stress response and different dimensions of personality trait are associated with different aspects of the stress response.

No abstract

No abstract

After continuous and prolonged cognitive workload, people typically show reduced behavioral performance and increased feelings of fatigue, which are known as “time-on-task (TOT) effects”. Although TOT effects are pervasive in modern life, their underlying neural mechanisms remain elusive. In this study, we induced TOT effects by administering a 20-minute continuous psychomotor vigilance test (PVT) to a group of 16 healthy adults and used resting-state blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to examine spontaneous brain activity changes associated with fatigue and performance. Behaviorally, subjects displayed robust TOT effects, as reflected by increasingly slower reaction times as the test progressed and higher self-reported mental fatigue ratings after the 20-minute PVT. Compared to pre-test measurements, subjects exhibited reduced amplitudes of low-frequency fluctuation (ALFF) in the default mode network (DMN) and increased ALFF in the thalamus after the test. Subjects also exhibited reduced anti-correlations between the posterior cingulate cortex (PCC) and right middle prefrontal cortex after the test. Moreover, pre-test resting ALFF in the PCC and medial prefrontal cortex (MePFC) predicted subjects’ subsequent performance decline; individuals with higher ALFF in these regions exhibited more stable reaction times throughout the 20-minute PVT. These results support the important role of both task-positive and task-negative networks in mediating TOT effects and suggest that spontaneous activity measured by resting-state BOLD fMRI may be a marker of mental fatigue.

Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Impulsivity is a personality trait associated with many maladaptive behaviors. Trait impulsivity is typically divided into three different dimensions, including attentional impulsiveness, motor impulsiveness, and non‐planning impulsiveness. In the present study, we examined the neuroanatomical basis of the multidimensional impulsivity trait. Eighty‐four healthy participants were studied with structural magnetic resonance imaging. Multiple regression analyses revealed that the score of motor impulsiveness was negatively correlated with gray matter volumes of the right supplementary motor area and paracentral lobule. A machine‐learning‐based prediction analysis indicated that decreased gray matter volumes of the supplementary motor area and paracentral lobule strongly predicted the decrease in motor impulsiveness control. Our findings provide insights into the predictive role of motor brain structures in motor impulsivity and inhibition control.

The present study examined the associations between recent life stress and responses to acute psychological stress, and how these associations varied with executive control. Heart rate (HR), heart rate variability (HRV), salivary cortisol, and affective states were measured before, during and after the Trier Social Stress Test (TSST), an effective laboratory stressor, in 54 healthy participants, and executive control function was tested with a Go/No-Go task in a neutral context on a different day. The hierarchical multiple regression analysis showed that high frequency of life stress during the last twelve months predicted blunted cardiovascular acute stress response, i.e., smaller HR and HRV reactivity. Moreover, the low executive control group showed a significant association between higher recent life stress and blunted acute stress response, which was not apparent in the high executive control group. The results suggested that greater executive control may benefit us with adaptive acute stress response under recent life stress. HIGHLIGHTSThe Trier Social Stress Test induces cardiovascular and cortisol responses. Higher life event frequency (LEF) predicts smaller cardiovascular stress response. Executive control plays a role in the link of LEF to stress response.

No abstract