Acute psychological stress promotes general alertness and attentional control processes: An ERP study

Stress in the collective: Psychophysiological reactivity to an orchestra concert as a collective naturalistic, real-life stressor of psychosocial nature

BACKGROUND & OBJECTIVES

The investigation of collective stress experiences, including collective stressors and the psychophysiological reactivity of a collective to these stressors, has been widely neglected so far. Here, we examined public non-professional orchestra concerts as collective naturalistic, real-life stressors of psychosocial nature and the resulting psychophysiological reactivity in a collective of non-professional orchestra musicians.

METHODS

The members of two non-professional music orchestras (N = 54) were accompanied during a public concert (stress condition) and a rehearsal (control condition). We repeatedly assessed heart rate, salivary cortisol, and excitement levels before, during, and after the concert/rehearsal in addition to the anticipatory cognitive stress appraisal.

RESULTS

We observed greater physiological reactivity to the concert compared to the rehearsal (p's ≤.017), with higher increases in heart rate levels in anticipation of and in reaction to the concert and in cortisol levels in reaction to the concert compared to the rehearsal. Moreover, orchestra members reported greater psychological reactivity to the concert than to the rehearsal (p's ≤.024) in terms of higher cognitive stress appraisal in anticipation and increased excitement levels before and during the concert compared to the rehearsal.

DISCUSSION

Our findings indicate that orchestra concerts by non-professional musicians constitute collective naturalistic, real-life stressors of psychosocial nature, resulting in significant psychophysiological stress responses with reactivity kinetics differing between the sympathetic-adrenal-medullary axis, the hypothalamic-pituitary-adrenal axis, and the psychological response. Potential implications and modulating factors need to be elucidated in future studies.

Triggered by your heart: Effects of cardioafferent traffic and stress on automatic responses in a Simon task

Variations in cardioafferent traffic are relayed to the brain via arterial baroreceptors and have been shown to modulate perceptual processing. However, less is known about the cognitive-behavioral consequences of these effects and their role during stress. Here, we investigated in how far automatic responses during the Simon task were modulated by exposure to a laboratory stressor and the different phases of the cardiac cycle. In this study, 30 participants performed three blocks of a combined horizontal and vertical Simon task, which is characterized by either sensorimotor or cognitive response conflicts, respectively. Before each block, subjects were exposed to both the cold pressor test (CPT) and a control condition according to a within-subjects design. Target stimuli were presented during either systole or diastole. Behavioral and EEG-correlates of task processing were assessed along with subjective, cardiovascular, and endocrine measures of stress. The stress induction was successful yielding significant increases in all these measures compared to control. Moreover, we found the expected Simon effects: in incompatible compared to compatible trials performance was decreased and LRP latency as well as anterior N2 area increased. Importantly, accuracy was improved in compatible but reduced in incompatible trials during systole vs. diastole but only in the horizontal Simon condition. Stress dampened N2 area, however, no interactions with cardiac cycle were evident. These results indicate a faciliatory effect of cardioafferent traffic on automated sensorimotor processes.

Exploring the 'black box' of anxiety: An ERP study of non-consciously triggered fear generalization

Individuals with anxiety disorders frequently display heightened fear responses, even in situations where there is no imminent danger. We hypothesize that these irrational fear responses are related to automatic processing of fear generalization. The initial automatic detection of stimuli often operates at a non-conscious level. However, whether fear generalization can occur when the cues are not perceived consciously remains unclear. The current study investigated the neurocognitive mechanisms underlying fear conditioning and its non-conscious and conscious generalization using a backward masking paradigm, combined with analysis of event-related potentials from electroencephalographic recordings. Behaviorally, participants showed heightened shock expectancy in response to non-conscious perceived generalization stimuli compared to those perceived consciously. Nonetheless, participants could not consciously distinguish between danger and safe cues in non-conscious trials. Physiologically, danger cues evoked larger frontal N1 amplitudes than safety cues in non-conscious trials, suggesting enhanced attention vigilance towards danger cues in the early sensory processing stage. Meanwhile, when fear generalization was conscious, it was accompanied by a larger P2 amplitude, indicating attention orientation or stimulus evaluation. In addition, fear conditioning was associated with sustained discrimination on P2, P3, and LPP. These findings collectively suggest that non-conscious fear generalization occurs at the neural level, yet additional control conditions are required to confirm this phenomenon on the US expectancy. Thus, non-consciously fear generalization may represent a mechanism that could trigger automatic irrational fear, highlighting the need for further research to explore therapeutic targets in anxiety disorders.

Effects of attentional deployment training for relieving negative emotion in individuals with subthreshold depression

OBJECTIVE

As a prodromal stage to major depressive disorder (MDD), subthreshold depression (StD) has a higher prevalence in the population, resulting in a greater healthcare burden. StD individuals' current negative emotion could be moderated by attentional deployment. However, it remains unclear whether attentional deployment training can mitigate subsequent negative emotion in StD individuals.

METHODS

Based on 160 participants, we combined decision task (Experiment 1, N = 69), eye-tracking (Experiment 2, N = 40), and EEG (Experiment 3, N = 51) techniques to investigate how one-week attentional deployment (gain-focus, GF) training modulated the emotional processing of negative stimulus and its underlying neural correlates in StD individuals.

RESULTS

After one-week GF training, StD individuals significantly reduced the first fixation time and total fixation time on the negative part (missed opportunities) of decision outcome and showed a decrease in emotional sensitivity to missed opportunities. An increase in N1 and decrease in P3 and LPP (late positive potentials) amplitudes, as well as a decrease in alpha oscillation, were observed when StD individuals faced missed opportunities after training. Additionally, the extent of reduction in StD individuals' emotional sensitivity to missed opportunities could be significantly predicted by the degree of decrease in alpha oscillation.

CONCLUSION

One-week attentional deployment training could modulate negative emotion in StD individuals and the degree of change in alpha oscillation might act as an objective indicator for the effectiveness of training.

SIGNIFICANCE

Our study provides a convenient and effective approach to alleviate the negative emotion of StD individuals.

The relationship between cardiorespiratory fitness and inhibitory control following acute stress: An ERP study

Although the relationships among acute stress, cardiorespiratory fitness (CRF), and cognitive function have been examined, whether CRF is related to behavioral and neuroelectric indices of inhibitory control following acute stress remains unknown. The purpose of the current study was to investigate the combined influence of acute stress and CRF on inhibitory control. Participants, aged 20-30 years, were stratified into the Higher-Fit (n = 31) and the Lower-Fit (n = 32) groups, and completed a Stroop task following the modified Maastricht Acute Stress Test (MAST) in the stress condition and the sham-MAST in the non-stress condition, during which electroencephalography was recorded. Behavioral (i.e., response time and accuracy) and neuroelectric (N2 and P3b components of the event-related potential) outcomes of inhibitory control were obtained. While the Higher-Fit group demonstrated shorter response times and higher accuracy than the Lower-Fit group following both the MAST and the sham-MAST, they also exhibited selective benefits of acute stress on inhibitory control performance (i.e., decreased response times and diminished interference scores). CRF-dependent alterations in neuroelectric indices were also observed, with the Higher-Fit group displaying smaller N2 and greater P3b amplitudes than the Lower-Fit group following the sham-MAST, and increased N2 and attenuated P3b amplitudes following the MAST. Collectively, these findings not only confirm the positive relationship between CRF and inhibitory control but also provide novel insights into the potential influence of CRF on inhibitory control and associated neuroelectric activity following acute stress.

The effect of chronic academic stress on intentional forgetting

This study investigated whether chronic academic stress could affect the directed forgetting (DF) process. Both the stress group (undergoing preparation for a major academic examination) and the control group performed a DF task. A forgetting cue was presented after a to-be-forgotten (TBF) word, whereas no cue appeared after a to-be-remembered (TBR) item in the study phase. An old/new recognition test was used in the test phase. The results showed that (1) the stress group showed a higher level of self-reported stress, state anxiety, negative affect, and decreased cortisol awakening response (CAR) compared with the control group, suggesting a higher level of stress for the stress group. (2) Both groups showed superior recognition performance of TBR than TBF items, suggesting a DF effect. (3) The stress group showed inferior recognition performance of TBF items and an enhanced DF effect compared with the control group. These results demonstrated that the intentional memory control process might be enhanced under chronic academic stress.

Does acute stress play a role in the lasting therapeutic effects of psychedelic drugs?

Psychedelic drugs, when used in the context of psychotherapy, can produce significant and long-lasting memories with enduring beneficial effects. Yet, the behavioral and neurobiological mechanisms that underlie these beneficial effects remain a mystery. Here, we suggest that both the quality and durability of memories of the drug-facilitated therapeutic experience may be mediated, in part, by the acute stress responses induced by the drugs. It is known that high doses of psychedelic drugs activate autonomic and hormonal stress responses. For evolutionarily adaptive reasons, acute stress is known to i) instill meaning to the immediate context in which it is experienced, and ii) lead to the formation of salient and lasting memories of the events surrounding the stress. Thus, the stress-inducing effect of psychedelic drugs may contribute to the reported sense of meaning, as well as the durability of the memory of the drug experience. When used in a therapeutic context these actions may i) enhance the salience of insights gained during the experience and ii) strengthen the memories formed by these experiences. Future empirical studies will help to determine whether acute stress contributes to the emotional significance and lasting effects of psychedelic-assisted psychotherapy.

Validation of the Chinese version of the Perceived Stress Scale-10 integrating exploratory graph analysis and confirmatory factor analysis

OBJECTIVE

The study aimed to initially assess the measurement properties of the 10-item simplified Chinese version of the Perceived Stress Scale (PSS-C-10) and as a first, assess a longitudinal measurement invariance (LMI).

METHODS

A longitudinal survey was conducted with a convenient sample of healthcare students using the PSS-C-10. We assessed the PSS-C-10 mainly using composite analytical approaches, including exploratory graph analysis (EGA) and confirmatory factor analysis (CFA) to suggest the best-fit factor structure and assess measurement invariance.

RESULTS

The EGA identified a two-factor structural solution with an accuracy of 98.6% at baseline and 100% at a 7-day follow-up. The CFA subsequently confirmed this structure, with a comparative fit index of 0.963 at baseline and 0.987 at follow-up, Tucker-Lewis index of 0.951 at baseline and 0.982 at follow-up, and root mean square error of approximation of 0.111 at baseline and 0.089 at follow-up. The LMI was supported by the goodness-of-fit indices, and their changes fell within the recommended cut-off range. Additionally, Cronbach's alpha (0.885 at baseline and 0.904 at follow-up), McDonald's omega (0.885 at baseline and 0.902 at follow-up), and an ICC value of 0.816 for 7 days demonstrated the robust reliability of the PSS-C-10.

CONCLUSION

The PSS-C-10 exhibited a stable two-factor structure with promising LMI and measurement properties.

Prospective Effects of Discrimination, Depressive Symptoms, and Cognitive Control Among Mexican-Origin Women

OBJECTIVES

Cognitive control predicts functional independence and cognitive health outcomes, but is yet to be known the extent to which social stress, like discrimination, may diminish cognitive control capacities in Mexican-origin women. We evaluated the prospective associations between everyday and ethnic discrimination on cognitive control and examined the mediating effects of depressive symptoms on these links. We further examined the extent to which associations varied by age and financial strain.

METHODS

We used data from 596 Mexican-origin women (average age = 38.89, standard deviation = 5.74) who participated in a 3-wave longitudinal study spanning 8 years (from 2012 to 2020). Participants completed measures of everyday and ethnic discrimination at Wave 1, depressive symptoms in Waves 1 and 2, and completed computer-based tasks of cognitive control at Wave 3. Self-reported assessments of financial strain were completed at Wave 2. Moderated mediation structural equation models were implemented to test hypotheses.

RESULTS

Depressive symptoms significantly mediated the prospective association between everyday/ethnic discrimination to cognitive control. Higher levels of everyday and ethnic discrimination at baseline were associated with more depressive symptoms at Wave 2, which were then related to poorer cognitive control (i.e., longer reaction time in congruent and/or incongruent trials) at Wave 3. There was no significant moderation of age. Among those with low financial strain, higher levels of everyday discrimination were related to faster response times.

DISCUSSION

Results revealed the long-term consequences of experiences with discrimination on cognitive control that operate through increased depressive symptoms and that may have some subtle differential effects across levels of financial strain.

Impact of acute psychosocial stress on attentional control in humans. A study of evoked potentials and pupillary response

Psychosocial stress has increased considerably in our modern lifestyle, affecting global mental health. Deficits in attentional control are cardinal features of stress disorders and pathological anxiety. Studies suggest that changes in the locus coeruleus-norepinephrine system could underlie the effects of stress on top-down attentional control. However, the impact of psychosocial stress on attentional processes and its underlying neural mechanisms are poorly understood. This study aims to investigate the effect of psychosocial stress on attentional processing and brain signatures. Evoked potentials and pupillary activity related to the oddball auditory paradigm were recorded before and after applying the Montreal Imaging Stress Task (MIST). Electrocardiogram (ECG), salivary cortisol, and subjective anxiety/stress levels were measured at different experimental periods. The control group experienced the same physical and cognitive effort but without the psychosocial stress component. The results showed that stressed subjects exhibited decreased P3a and P3b amplitude, pupil phasic response, and correct responses. On the other hand, they displayed an increase in Mismatch Negativity (MMN). N1 amplitude after MIST only decreased in the control group. We found that differences in P3b amplitude between the first and second oddball were significantly correlated with pupillary dilation and salivary cortisol levels. Our results suggest that under social-evaluative threat, basal activity of the coeruleus-norepinephrine system increases, enhancing alertness and decreasing voluntary attentional resources for the cognitive task. These findings contribute to understanding the neurobiological basis of attentional changes in pathologies associated with chronic psychosocial stress.

Active inhibition of the retro-cue effect in visual working memory: Evidence from event-related potential

This study used the event-related potential (ERP) technique to investigate whether active inhibition exists in retro-cue Effect (RCE) in visual working memory using modified retro-cue tasks. In this modified task, the participants were first asked to memorize six color blocks and then presented with directed remembering or directed forgetting cues; finally, their working memory performance was tested. For behavioral results, due to the extension of the memory interval, this study did not find RCE in accuracy but reflected it in the total reaction time. For ERP results, the frontal late positive potential (LPP) followed by the directed forgetting condition was larger than that followed by directed remembering and baseline conditions, and there was no significant difference between directed remembering and baseline conditions. There was no significant difference in parietal P3 followed by both the directed remembering and directed forgetting conditions, which were significantly larger than the baseline condition. This result reveals that active inhibition plays an important role in directed forgetting RCE. There was a correlation between parietal P3 and frontal LPP with the same time window but different scalp regions in the directed forgetting condition, indicating a potential relationship between active inhibition and retelling in directed forgetting RCE.

High-trait anxious individuals show positive relationship between HRV and threat vigilance

Selectively attending to threat-related stimuli in the environment, known as threat bias (TB), is a prominent feature of anxiety. Individuals with high anxiety also tend to show lower heart rate variability (HRV), a reflection of reduced parasympathetic cardiac control. Previous investigations have established associations between low HRV and various attentional processes that facilitate attention to threat, though these have primarily been conducted among non-anxious individuals. The current analysis, derived from a larger TB modification study, examined the relationship between TB and HRV among a young, nonclinical sample of individuals with either high or low trait anxiety (HTA, LTA, respectively; M_age  = 25.8, SD = 13.2, 61.3% female). Consistent with expectations, HTA (β = -.18, p = .087) trended toward an association with higher threat vigilance. A significant moderation effect showed the relationship between HRV and threat vigilance was influenced by TA (β = .42, p = .004). Simple slopes analysis revealed that for the LTA group, lower HRV trended toward higher threat vigilance (p = .123), consistent with expectations. However, this relationship was unexpectedly reversed for the HTA group, for whom higher HRV was a significant predictor of higher threat vigilance (p = .015). These results are interpreted within a cognitive control framework, in which regulatory ability, as assessed via HRV, may influence which cognitive strategy is employed when encountering threatening stimuli. Results suggest that HTA individuals with greater regulatory ability may employ a contrast avoidance mechanism, while those with reduced regulatory ability engage in cognitive avoidance.

Automatic attention to sexual stimuli: exploring the role of neuroticism and sexual excitation/inhibition through event-related potentials

BACKGROUND

Previous findings have shown that neuroticism is a higher-order vulnerability factor in the development and maintenance of sexual dysfunctions and can have an impact on the attentional processing of sexual stimuli; however, the influence of psychosexual dimensions on the early automatic phases of such cognitive processes has not been established yet.

AIM

To examine the mediating role of sexual inhibition/excitation propensity in the relationship between neuroticism and automatic attention to visual erotica and to identify the neuroelectric correlates of such a process.

METHODS

We analyzed the answers provided by 58 individuals on the Neuroticism subscale of the NEO Personality Inventory-Revised and the Sexual Inhibition/Excitation Scales. Event-related potentials (ERPs) were recorded during a modified oddball paradigm containing romantic and sexually explicit pictures. Parallel mediations were performed to simultaneously test the mediating role of sexual inhibition/excitation in the relationship between neuroticism and each ERP.

OUTCOMES

Three early attention ERP components (P1, P2, and N2) were assessed.

RESULTS

Findings revealed an indirect effect of neuroticism on automatic attention, via sexual inhibition due to threat of performance failure (SIS1), for romantic and sexually explicit stimuli. This effect was significant only for component N2, which showed increased amplitudes and earlier latencies in participants with high SIS1.

CLINICAL IMPLICATIONS

Sexual stimuli, due to their emotional valence and arousal potential, might be perceived as virtually threatening by individuals with neuroticism, who may benefit from strategies that decrease hyperarousal and sympathetic activation.

STRENGTHS AND LIMITATIONS

This was one of the first studies to analyze neuroelectric activity associated with automatic attention toward sexual stimuli in relation to personality and sexual excitation/inhibition propensity. Nevertheless, the limited number of participants demands caution in generalizing the results.

CONCLUSION

These results provide a better understanding of the relationship between personality and sexual cognition and open new avenues of research in relation to other automatic cognitive phenomena related to human sexual behavior.

Threat-induced alterations in cognition and associations with dysregulated behavior

Previous literature suggests that threat disrupts cognitive control, especially for those prone to engaging in dysregulated behaviors (i.e., maladaptive attempts at regulating stress). However, this relationship is not well understood and has yet to be directly examined. The current study extends previous literature by examining the link between individual differences in dysregulation and threat-related alterations in neurocognitive and behavioral indicators of cognitive control. Using a diverse community sample (N = 143), we recorded participants' brain activity during a flanker task under conditions of predictable, unpredictable, and no threat-of-shock. Findings revealed a nuanced relationship, whereby predictable threat, relative to unpredictable threat, was associated with larger N2 to flankers, perhaps at the expense of a reduced later P3. We also found a relationship between proneness toward dysregulated behaviors and threat-induced alterations of cognitive control, with those higher in dysregulation showing reduced conflict P3 differentiation and accuracy interference during threat vs. no threat conditions. This research expands what is known about how threat can modulate cognition in everyday life and linked it to dysregulated behaviors with high societal burden.

The Chinese Version of the Perceived Stress Questionnaire-13: Psychometric Properties and Measurement Invariance for Medical Students

Purpose

Stress may relate to an increased risk of psychological and physical disorders. Thus, a brief and efficient measurement instrument for researchers to measure stress is essentially needed.

Participants and Methods

To assess measurement properties of the validated Chinese version of the Perceived Stress Questionnaire-13 (PSQ-C-13), we conducted a two-wave longitudinal study from September to December, 2021 with a convenient sample of medical students.

Results

A two-factor (constraint and imbalance) structure showed good fit indices (Comparative Fit Index [CFI] = 0.972, Tucker-Lewis Index [TLI] = 0.966, Root Mean Square Error of Approximation [RMSEA] = 0.062). Spearman correlations with the Chinese Perceived Stress Scale-10 illustrated that convergent validity of the PSQ-C-13 was relatively satisfactory (r = 0.678 [baseline], 0.753 [follow-up]). Measurement invariance was supported across subgroups (gender, age, home location, single-child status, monthly households' income, and part-time status) and time points. Internal consistency was sound (Cronbach's α = 0.908 [baseline], 0.922 [follow-up]; McDonald's ω = 0.909 [baseline], 0.923 [follow-up]). Stability between time points was good (Intraclass Correlation Coefficient = 0.834).

Conclusion

The two factors of the PSQ-C-13 including constraint and imbalance may adequately measure the level of stress on participants. The PSQ-C-13 is a convenient and efficient instrument that contains valid and reliable psychometric properties.

Evaluation of changes in the cognitive function of adult cynomolgus monkeys under stress induced by audio-visual stimulation by applying modified finger maze test

Stress in life is ubiquitous and unavoidable. Prolonged exposure to severe stress can lead to physical intolerance and impair cognitive function. Non-human primates are considered to be the best animal model for studying cognitive function, especially memory and attention. The finger maze test, with the advantages of short training time and lower cost, is recommended to evaluate learning and memory in non-human primates. In this study, we modified the finger maze test method to evaluate the cognitive function of single-housed cynomolgus monkeys. The flexibility and attention of cynomolgus monkeys were assessed by performing the complex task test and the stranger intrusion interference test, respectively, which increased the difficulty of obtaining rewards, and the ability of long-term memory was also evaluated by the memory test. Furthermore, the changes in cognitive function of the cynomolgus monkeys were tested by using the finger maze test after audio-visual stimulation, and the changes in the cortisol levels during stimulation were also analyzed. We found that, after completing the learning test, there was no significant decrease in their success rate when monkeys processed multitasks at the same time. In the stranger intrusion interference test, all subjects were distracted, but the accuracy did not decrease. The monkeys completed the memory tests in the 1st and 2nd months after the learning tests, with a high success rate. However, the success rate decreased significantly at the end of the 4th month. During audio-visual stimulation, the plasma cortisol level significantly increased in the first 2 months and was maintained at a high level thereafter. One month after audio-visual stimulation, the accuracy of the memory test was significantly reduced, and the total time of distraction was significantly prolonged. In conclusion, chronic audio-visual stimulation can increase blood cortisol levels and impair cognitive function. The modified finger maze test can evaluate many aspects of cognitive function and assess the changes in the cognitive function of adult cynomolgus monkeys under stress.

Fear of negative evaluation modulates the processing of social evaluative feedback with different valence and contexts

Fear of negative evaluation (FNE) is a susceptible and maintaining factor of social anxiety disorders. However, the question, how people process negative evaluation is influenced by individual differences in FNE, is poorly understood. To clarify the habitual processing characteristics of individuals with different levels of FNE, electroencephalography was recorded when two groups of participants with high FNE (hFNE) and low FNE (lFNE) performed a social evaluation perception task in which the feedback context/source (human vs. a computer) and valence (thumb-up/like vs. thumb-down/dislike) were manipulated. We found effects of feedback source and valence on N1, P2, and P3, which reflect early attention, integrated perception, and elaborative processing, respectively, as well as general reward effects on reward positivity (RewP) across contexts. Importantly, compared to the lFNE group, the hFNE group showed larger midfrontal N1 and theta oscillation in response to negative feedback indicating dislike (vs. like), and also showed larger P3. These findings suggest that individuals with hFNE are more attentional vigilance to negative (vs. positive) social feedback, implying that individuals with different levels of FNE assign different implicit threat values to social-evaluation threat stimuli.

Feeling rushed? Perceived time pressure impacts executive function and stress

Executive function (EF) is critical to everyday life, but it can be undermined by adverse psychological states like stress and negative affect. For example, inadequate time to perform a task is a common stressor that can disrupt EF. Although the impact of actual time pressure on EF has been established, little is known about how self-generated, perceived time pressure (PTP) affects EF in the absence of objective time limits. We chose Eriksen’s Flanker task as an index of cognitive inhibition, a key component of EF, and we varied the interval between successive trials, the inter-trial interval (ITI), to proxy PTP. This manipulation strongly impacted task performance: shrinking the ITI to increase PTP diminished cognitive inhibition and increased both stress and negative affect. Subsequently lengthening the ITI to decrease PTP reversed nearly all of these effects, except stress, which persisted. Multilevel linear regression modeling revealed that ITI and stress predicted inhibition, and exploratory mediation modeling suggested that stress mediates the relationship between ITI and inhibition. These findings validate perceived time pressure as an empirical stressor and demonstrate EF’s sensitivity to changes in PTP.

Stress effects on the top-down control of visuospatial attention: Evidence from cue-dependent alpha oscillations

Stress is assumed to inhibit the top-down control of attention and to facilitate bottom-up processing. Evidence from human experiments, however, remains scarce. Previous studies have addressed how stress affects the interplay of bottom-up and top-down mechanisms of attention. A key open question is in how far such effects can actually be attributed to a stress-induced modulation of top-down attention control. We sought to isolate top-down from bottom-up effects by assessing stress effects on anticipatory changes in alpha oscillations that precede stimulus processing. Participants performed in a cued target detection task in which a cue prompted them to covertly shift their attention to left or right screen positions, 20 min after being exposed to the bilateral feet cold pressor test or a warm water control procedure. The stressor led to a substantial increase in cortisol, peaking 20 min post stressor, along with rises in heart rate, blood pressure, and subjective ratings of stress and arousal. As expected, cued attention deployment led to higher alpha power over posterior electrodes contralateral versus ipsilateral to the attended hemifield during the cue-target interval. Importantly, this purely endogenous effect was potentiated by stress, however, significant differences were restricted to the middle of the cue-target interval and thus temporally separated from the appearance of the target. These results indicate that stress does not impair top-down attentional control per se but may introduce a qualitative change modulating the way attention is deployed to meet action goals.

The Effect of Safety Signs on the Monitoring of Conflict and Erroneous Response

The safety sign is important in our daily life and workplace to prevent potential safety issues. However, it remains undetermined whether the safety signs would influence the cognitive control ability of the people, which serves to guide the behaviors in a goal-directed manner. Therefore, this study aimed to examine the effect of safety signs on cognitive control by uncovering the behavioral performance and neural manifestations underlying the monitoring of conflict and error. The participants performed a flanker task after watching low- and high-hazard safety signs with the electroencephalogram (EEG) data recorded continually. The behavioral results indicated a classic congruency effect with higher accuracy rate and faster response time under a congruent condition compared to an incongruent condition. However, no hazard effect on behavioral performances was observed. The results of event-related potentials (ERPs) demonstrated a more negative N2 elicited by the incongruent trials and an increased (error-related negativity) ERN difference between the error and correct responses in the high-hazard condition compared to those in the low-hazard condition, implying that the monitoring of the conflict and error were both enhanced after watching the high-hazard safety signs. This study contributes to the understanding of the relationship between safety signs and cognitive control, and further expand the measurements that can be applied to assess the effectiveness of safety signs design.

Representing strangers in personal space triggers coding of defensive hand movement

Our brain codes manipulable tools as possibilities for action, particularly for those surrounding the body. Recent studies showed people would adjust their motor program when observing others around their own bodies (i.e. in the personal space). However, it remained unclear whether representing a personal space invader can automatically trigger motor coding. To address this, we devised an interaction task to measure the activation of pushing movements in facing a stranger approaching into personal space. The LRP (lateralized readiness potential) analyses revealed that observing a stranger in personal space caused an initial LRP bias associated with pushing movements, and an LRP deflection before responding of pull, suggesting representing personal space invaders activated the motor coding of push. The behavioral results showed the personal space intrusion prolonged the reaction time of participants' subsequent instructed pulling responses. The results of experiment 2 confirmed the behavioral observation of experiment 1 and further revealed the relationship between the response bias of push and social anxiety. Together, the present study demonstrates representing a stranger in personal space activated coding of defensive hand movements and biased subsequent motor responses.

Stress effects on the oddball P300 and N2 in males and females

We examined the effect of psychosocial stress on electrophysiological markers of novelty and deviance processing, the N2 and P300, as well as sex differences therein. Participants underwent the Trier Social Stress Test (TSST) or a control procedure, followed by an oddball paradigm. A physiological stress response was induced in both sexes in the TSST condition. Furthermore, a reduced target P300 amplitude was elicited in the TSST condition in fronto-central electrodes, an effect that did not differ in magnitude between both sexes. By contrast, stressor effects on N2 amplitude differed by sex: In females, N2 amplitude was decreased in the TSST condition, while in males, no stress effects were observed. Exploratory correlational analyses suggested that a stress-induced P300 amplitude reduction, at least in males, could be due to a modulation of adrenergic activity. These results are consistent with sex differences in the manner in which stress affects lower-level, stimulus-driven vs. higher-level, more controlled processing stages.

Perceived Stress, Personality Traits, and State of Victim's Consciousness: Impact on Tourniquet Application Time and Effectiveness

INTRODUCTION

One of the main avoidable causes of combat-related injury death is extremity hemorrhage. Even with regular training, failure to properly apply a tourniquet is common. In this study, we sought to assess if rescuer's stress and personality traits, along with victim's state of consciousness, had a role to explain tourniquet application failure.

MATERIALS AND METHODS

Eighty-seven soldiers completed a sociodemographic and personality questionnaire (perceived stress, active altruism, mindfulness, and empathy) during a forward combat casualty care course. Then, they underwent a leg hemorrhage simulation on a randomly conscious or unconscious victim. Tourniquet application time and effectiveness (using popliteal artery Doppler) were recorded.

RESULTS

Tourniquet application effective rate was 37% and soldiers with higher levels of perceived stress were at greater risk of failure, especially on a conscious victim. Participants who deployed overseas and those who have undergone combat rescue training were significantly quicker to apply a tourniquet. Altruist and empathetic caregivers were slower to apply the tourniquet while mindful ones were faster.

CONCLUSIONS

Combat-related injuries, even simulated, not only involve the rescuer's technical skills but also their ability to deal with stressful external stimuli. Tourniquet application speed seems to be influenced by perceived stress and personality traits of the rescuers. Frequent failures justify repeated training, and one way to pursue improvement could be to develop a personalized pedagogy adapting to the needs of the students according to their current skillset but also their perceived stress and personality determinants. In the pedagogical process (planning, goal setting, teaching, and evaluating), the state of consciousness of the victim seems to be a parameter that needs to be accounted for, but further studies are required to accurately describe its influence.

Monitorization of Autonomic Stress Response of Nurse Students in Hospital Clinical Simulation

The aims of this study were to analyze the autonomic stress response of nurse degree students during a hospital clinical simulation and to analyze differences in the autonomic stress response of nurse degree students during a hospital clinical simulation depending on their psychological profile. We analyzed in 45 nurse students their psychological profile (purpose in life, coping flexibility, perceived stress, Framingham Type A Behavior, and personality) and the autonomic modulation by the heart rate variability in a hospital clinical simulation. Students presented decreased heart rate variability and different autonomic stress responses depending on the different psychological parameters evaluated. We concluded that a hospital clinical simulation produced a large sympathetic modulation of nurse students that was maintained during the entire clinical simulation. The autonomic response was modulated by the psychological profile of students, showing higher purpose in life, perceived stress, and neuroticism, presenting higher parasympathetic modulation.

Effect of Acute Psychological Stress on Motion-in-Depth Perception: An Event-Related Potential Study

The present study explored the intrinsic event-related potential (ERP) features of the effects of acute psychological stress on the processing of motion-in-depth perception using a dual-task paradigm. After a mental arithmetic task was used to induce acute psychological stress, a collision task was used to evaluate motion-in-depth perception. The error value and average amplitude of late slow waves (SW) were significantly larger for the earlier colliding spheres' than for the later colliding spheres. The P1 peak latency in the left occipital region was significantly shorter than that of the right occipital region in the motion-in-depth perception task. Compared to the control condition, the estimated value of residual time-to-collision and error value were significantly reduced, and the N1 peak amplitude and the SW averaged amplitude were significantly increased in the stress condition. Longer motion-in-depth time improved discrimination accuracy and decreased the investment of cognitive resources. Acute psychological stress increased behavioral performance and enhanced attention resources on the motion-in-depth perception task together with greater investment of cognitive resources.

Acute stress reduces the emotional attentional blink: Evidence from human electrophysiology

The present study is the first to examine the time-dependent mechanism of acute stress on emotional attentional blink (EAB) with event-related potential (ERP) measures. We explored the stage characteristics of stress affecting EAB, whether it affects the early selective attention process (marked by early posterior negativity) or the late working memory consolidation (marked by late positive potential). Sixty-one healthy participants were exposed to either a Trier Social Stress Test (TSST) or a control condition, and salivary cortisol was measured to reflect the stress effect. ERPs were recorded during an attentional blink (AB) paradigm in which target one (T1) were negative or neutral images. Results showed stress generally reduced AB effects. Specifically, stress promoted the early selective attention process of target two (T2) following a neutral T1 but did not affect T2 consolidation into working memory. Correlational analyses further confirmed the positive effect of cortisol and negative emotional state on AB performance. Moreover, the ERP results of acute stress on AB conformed to the trade-off effect between T1 and T2; that is, stress reduced T1 late working memory consolidation and improved T2 early selective attention process. These findings further demonstrated that stress did not change the central resource limitation of AB. In general, stress generates a dissociable effect on AB early- and late-stage processing; namely, acute stress reduce the AB effect mainly from the improvement of participants' overall ability to select the targets in the early stage.

Stressors of COVID-19 and stress consequences: The mediating role of rumination and the moderating role of psychological support

BACKGROUNDS AND AIMS

As COVID-19 spreads rapidly, this global pandemic has not only brought the risk of death but also spread unbearable psychological pressure to people around the world. The aim of this study was to explore (a) the mediating role of rumination in the association between stressors of COVID-19 and stress consequences of college students, and (b) the moderating role of psychological support in the indirect relationship between stressors of COVID-19 and stress consequences of college students.

METHODS

Eight hundred and forty-one Chinese college students (Mage = 19.50 years, SD = 1.580) completed the measures of stressors of COVID-19, stress consequences, rumination, and psychological support.

RESULTS

Stressors of COVID-19 were significantly positively associated with stress consequences, and mediation analyses indicated that rumination partially mediated this association. Moderated mediation analysis further revealed that psychological support buffered the relation between stressors of COVID-19 and rumination, as well as the relation between rumination and stress consequences.

DISCUSSION AND CONCLUSION

Findings of this study demonstrated that stressors associated with COVID-19 is positively related to rumination, which in turn, is related to stress consequences in college students. However, psychological support buffered this effect at both indirect mediation paths, suggesting that college students with greater psychological support may be better equipped to prevent negative stress consequences.

Central Sympathetic Nervous System Effects on Cognitive-Motor Performance

Abstract. The intriguing interplay between acute stress physiology and cognitive processes has long been noted. However, while stress-induced release of glucocorticoids has repeatedly been shown to impact brain mechanisms underlying cognition and memory, less experimental research addressed the effects of stress-induced central sympathetic nervous system (SNS) activation on cognitive performance. Moreover, despite the long-standing notion that the way performance is modulated by arousal may crucially depend on task complexity, mechanistic research demonstrating a direct, causal influence of altered SNS activity is scarce. Twelve healthy men participated in a placebo-controlled, pharmacologic dose–response study involving three within-subject assessments (1-week intervals). Subjective and objective indices of SNS activity as well as reaction time (RT) in three different tasks varying in cognitive demand (simple RT, choice RT, and verbal RT in complex mental arithmetic) were assessed during modulation of central SNS tone by intravenous infusions of dexmedetomidine (alpha2-agonist), yohimbine (alpha2-antagonist), and placebo. Cognitive performance was negatively affected by alpha2-agonism in all task conditions. By contrast, administration of yohimbine improved simple RT, while diminishing complex RT, supporting the assumption of a nonlinear way of action depending on task characteristics. Our results highlight the consequences of central (noradrenergic) SNS activation for cognitive-motor performance in RT tasks of varying complexity.