Effects Of Acute Psychosocial Stress Research Articles

Endocannabinoids and Stress-Related Neurospsychiatric Disorders: A Systematic Review and Meta-Analysis of Basal Concentrations and Response to Acute Psychosocial Stress.

Background: Dysregulation of the endocannabinoid (eCB) system is implicated in various stress-related neuropsychiatric disorders (SRDs), including anxiety, depression, and post-traumatic stress disorder (PTSD). In this systematic review and meta-analysis, our objectives were to characterize circulating anandamide (AEA) and 2-arachidonoylglycerol (2-AG) concentrations at rest and in response to acute laboratory-based psychosocial stress in individuals with SRDs and without (controls). Our primary aims were to assess the effects of acute psychosocial stress on eCB concentrations in controls (Aim 1), compare baseline (prestress) eCB concentrations between individuals with SRDs and controls (Aim 2), and explore differential eCB responses to acute psychosocial stress in individuals with SRDs compared with controls (Aim 3). Methods: On June 8, 2023, a comprehensive review of the MEDLINE (PubMed) database was conducted to identify original articles meeting inclusion criteria. A total of 1072, 1341, and 400 articles were screened for inclusion in Aims 1, 2, and 3, respectively. Results: Aim 1, comprised of seven studies in controls, revealed that most studies reported stress-related increases in AEA (86%, with 43% reporting statistical significance) and 2-AG (83%, though none were statistically significant except for one study in saliva). However, meta-analyses did not support these patterns (p's>0.05). Aim 2, with 20 studies, revealed that most studies reported higher baseline concentrations of both AEA (63%, with 16% reporting statistical significance) and 2-AG (60%, with 10% reporting statistical significance) in individuals with SRDs compared with controls. Meta-analyses confirmed these findings (p's<0.05). Aim 3, which included three studies, had only one study that reported statistically different stress-related changes in 2-AG (but not AEA) between individuals with PTSD (decrease) and controls (increase), which was supported by the meta-analysis (p<0.001). Meta-analyses showed heterogeneity across studies and aims (I2=14-97%). Conclusion: Despite substantial heterogeneity in study characteristics, samples, and methodologies, consistent patterns emerged, including elevated baseline AEA and 2-AG in individuals with SRDs compared with controls, as well as smaller stress-related increases in 2-AG in individuals with SRDs compared with controls. To consider eCBs as reliable biomarkers and potential intervention targets for SRDs, standardized research approaches are needed to clarify the complex relationships between eCBs, SRDs, and psychosocial stress.

The effect of acute psychosocial stress on salivary cortisol and testosterone responses in men and women: The role of impulsivity

Personality-like traits such as impulsivity may be associated with interindividual variation in endocrine function and in physiological reactivity to psychosocial stress. This study investigated the relationship between impulsivity, cortisol, and testosterone both in baseline conditions and in response to psychosocial stress in a mixed-sex sample of college students (mean age = 22.275, SD = 4.321). Half of our study participants (total n = 120, 60 male, 60 female) underwent a Trier Social Stress Test (TSST) (n = 60, 31 male, 29 female) and half were in a control condition (n = 60, 29 male, 31 female). All of them provided saliva samples to assess hormone levels at three-time points (i.e., “baseline”, “during”, and “after” either the TSST or control condition) and completed the Eysenck Impulsivity Questionnaire (EIQ). We found positive correlations between the global EIQ score, its dimension ‘venturesomeness’, and testosterone levels when data for males and females were analyzed together. We also found a negative correlation between ‘venturesomeness’ and cortisol changes. The EIQ dimension ‘impulsivity’ influenced cortisol changes in both sexes, whereas the global EIQ influenced testosterone changes only in females in the control condition. Our results highlight potential sex differences in the association between steroid hormones and various aspects of impulsivity and suggest limited effects of impulsivity dimensions on the regulation of cortisol and testosterone levels.

NUCB2/nesfatin-1 in the acute stress response of obese women with high and low anxiety

NUCB2/nesfatin-1 is an anorexigenic peptide hormone first known for its effects on energy homeostasis. More recently, a growing evidence suggests a role of NUCB2/nesfatin-1 in emotion regulation, particularly in the modulation of anxiety, depression and emotional stress response. Since stress-related mood disorders are often comorbid with obesity, we investigated the effect of acute psychosocial stress on circulating NUCB2/nesfatin-1 in obese women and normal-weight controls and its association with symptoms of anxiety. Forty women, 20 obese and 20 normal-weight controls, (aged between 27 and 46 years) were exposed to the Trier Social Stress Test (TSST). We assessed changes of plasma NUCB2/nesfatin-1, salivary cortisol, heart rate and subjective emotional state. Symptoms of anxiety (GAD-7), depressiveness (PHQ-9), perceived stress (PSQ-20), disordered eating (EDE-Q, EDI-2) and health-related quality of life (SF-8) were measured psychometrically. Obese women were further subdivided in a high and low anxiety group. Women with obesity displayed higher psychopathology compared to normal-weight controls. The TSST induced a biological and psychological stress response in both groups (p < 0.001). In normal-weight controls NUCB2/nesfatin-1 increased in response to stress (p = 0.011) and decreased during recovery (p < 0.050), while in obese women only the decrease during recovery was significant (p = 0.002). Obese women with high anxiety displayed higher NUCB2/nesfatin-1 levels than those in the low anxiety group (TSST: +34 %, p = 0.008; control condition: +52 %, p = 0.013).Our data substantiate the involvement of NUCB2/nesfatin-1 in the modulation of stress and anxiety. It remains unclear whether the attenuated stress response in obese subjects is due to metabolic changes or mental comorbidity.

Effects of acute psychosocial stress on source level EEG power and functional connectivity measures

The usage of EEG to uncover the influence of psychosocial stressors (PSSs) on neural activity has gained significant attention throughout recent years, but the results are often troubled by confounding stressor types. To investigate the effect of PSSs alone on neural activity, we employed a paradigm where participants are exposed to negative peer comparison as PSS, while other possible stressors are kept constant, and compared this with a condition where participants received neutral feedback. We analyzed commonly used sensor level EEG indices (frontal theta, alpha, and beta power) and further investigated whether source level power and functional connectivity (i.e., the temporal dependence between spatially seperated brain regions) measures, which have to our knowledge not yet been used, are more sensitive to PSSs than sensor level-derived EEG measures. Our results show that on sensor level, no significant frontal power changes are present (all p’s > 0.16), indicating that sensor level frontal power measures are not sensitive enough to be affected by only PSSs. On source level, we find increased alpha power (indicative of decreased cortical activity) in the left- and right precuneus and right posterior cingulate cortex (all p’s < 0.03) and increased functional connectivity between the left- and right precuneus (p < 0.001), indicating that acute, trial based PSSs lead to decreased precuneus/PCC activity, and possibly indicates a temporary disruption in the self-referential neural processes of an individual.

Acute stress alters probabilistic reversal learning in healthy male adults.

Behavioural adaptation is a fundamental cognitive ability, ensuring survival by allowing for flexible adjustment to changing environments. In laboratory settings, behavioural adaptation can be measured with reversal learning paradigms requiring agents to adjust reward learning to stimulus-action-outcome contingency changes. Stress is found to alter flexibility of reward learning, but effect directionality is mixed across studies. Here, we used model-based functional MRI (fMRI) in a within-subjects design to investigate the effect of acute psychosocial stress on flexible behavioural adaptation. Healthy male volunteers (n= 28) did a reversal learning task during fMRI in two sessions, once after the Trier Social Stress Test (TSST), a validated psychosocial stress induction method, and once after a control condition. Stress effects on choice behaviour were investigated using multilevel generalized linear models and computational models describing different learning processes that potentially generated the data. Computational models were fitted using a hierarchical Bayesian approach, and model-derived reward prediction errors (RPE) were used as fMRI regressors. We found that acute psychosocial stress slightly increased correct response rates. Model comparison revealed that double-update learning with altered choice temperature under stress best explained the observed behaviour. In the brain, model-derived RPEs were correlated with BOLD signals in striatum and ventromedial prefrontal cortex (vmPFC). Striatal RPE signals for win trials were stronger during stress compared with the control condition. Our study suggests that acute psychosocial stress could enhance reversal learning and RPE brain responses in healthy male participants and provides a starting point to explore these effects further in a more diverse population.

Why Being 'Stressed' Is 'Desserts' in Reverse-The Effect of Acute Psychosocial Stress on Food Pleasure and Food Choice.

The link between acute stress, food pleasure and eating behavior in humans by employing measures of individual reward mechanisms has not been investigated as of yet. Having these insights is key to understanding why many people experience a change in eating behavior when experiencing stress. Thirty-five Danes (mean age 21.71 years) underwent a stress-inducing and relaxation-inducing task based on a randomized cross-over study design. Both tasks were combined with the Leeds Food Preference Questionnaire, to investigate the effect of stress on specific measures of food reward. Furthermore, participants chose a snack, as a covert measure of actual food choice. The study found no effect on explicit liking, explicit wanting or relative preference. For implicit wanting, an effect was detected on high-fat sweet foods, with increasing scores for the stress-induced condition. Moreover, 54% chose a different snack following the stress-inducing condition. Interestingly, 14% chose to change their snack choice to no snack at all. Results suggest acute psychosocial stress can increase cravings for highly palatable foods for some, while for others an experience of loss of appetite prevails. Overall, this study points to a further understanding of why consumers have issues with making healthy food choices, ultimately affecting public health too.

Risky Decision Making Under Stressful Conditions: Men and Women With Smaller Cortisol Elevations Make Riskier Social and Economic Decisions.

Men often make riskier decisions than women across a wide range of real-life behaviors. Whether this sex difference is accentuated, diminished, or stable under stressful conditions is, however, contested in the scientific literature. A critical blind spot lies amid this contestation: Most studies use standardized, laboratory-based, cognitive measures of decision making rather than complex real-life social simulation tasks to assess risk-related behavior. To address this blind spot, we investigated the effects of acute psychosocial stress on risk decision making in men and women (N = 80) using a standardized cognitive measure (the Iowa Gambling Task; IGT) and a novel task that simulated a real-life social situation (an online chatroom in which participants interacted with other men and women in sexually suggestive scenarios). Participants were exposed to either an acute psychosocial stressor or an equivalent control condition. Stressor-exposed participants were further characterized as high- or low-cortisol responders. Results confirmed that the experimental manipulation was effective. On the IGT, participants characterized as low-cortisol responders (as well as those in the Non-Stress group) made significantly riskier decisions than those characterized as high-cortisol responders. Similarly, in the online chatroom, participants characterized as low-cortisol responders (but not those characterized as high-cortisol responders) were, relative to those in the Non-Stress group, significantly more likely to make risky decisions. Together, these results suggest that at lower levels of cortisol both men and women tend to make riskier decisions in both economic and social spheres.

Effects of acute psychosocial stress on interpersonal cooperation and competition in young women

Although tend-and-befriend is believed to be the dominant stress response in women, little is known regarding the effects of acute psychosocial stress on different dynamic social interactions. To measure these effects, 80 female participants were recruited, paired into the dyads, and instructed to complete cooperative and competitive key-pressing tasks after experiencing acute stress or a control condition. Each dyad of participants should press the key synchronously when the signal was presented in the cooperative task and as fast as possible in the competitive task. During the tasks, brain activities of prefrontal and right temporo-parietal areas were recorded from each dyad using functional near-infrared spectroscopy (fNIRS). The results showed that acute psychosocial stress evidently promoted competitive behavior, accompanied by increased interpersonal neural synchronization (INS) in the right dorsolateral prefrontal cortex. Despite the lack of a significant difference in the overall cooperation rate, the response time difference between two stressed participants markedly declined over time with more widespread INS in the prefrontal cortex, suggesting that there ensued cooperative improvement among stressed women. These findings behaviorally and neurologically revealed context-dependent response patterns to psychosocial stress in women during dynamic social interactions.

No Effects of Acute Psychosocial Stress on Working Memory in Older People With Type 2 Diabetes.

Type 2 diabetes (T2D) has been considered a public health threat due to its growing prevalence, particularly in the older population. It is important to know the effects of psychosocial stress and its potential consequences for some basic cognitive processes that are important in daily life. Currently, there is very little information about how people with T2D face acute psychosocial stressors, and even less about how their response affects working memory (WM), which is essential for their functionality and independence. Our aim was to characterize the response to an acute laboratory psychosocial stressor and its effects on WM in older people with T2D. Fifty participants with T2D from 52 to 77 years old were randomly assigned to a stress (12 men and 12 women) or control (12 men and 14 women) condition. Mood and physiological (cortisol, C, and salivary alpha-amylase, sAA) responses to tasks were measured. In addition, participants completed a WM test before and after the stress or control task. Our results showed that the TSST elicited higher negative affect and greater C and sAA responses than the control task. No significant differences in WM were observed depending on the exposure to stress or the control task. Finally, participants who showed higher C and sAA responses to the stressor had lower WM performance. Our results indicate that medically treated older adults with T2D show clear, typical mood and physiological responses to an acute psychosocial stressor. Finally, the lack of acute psychosocial stress effects on WM suggests that it could be related to aging and not to this disease, at least when T2D is adequately treated.

Effect of acute psychosocial stress on the brain-derived neurotrophic factor in humans – a randomized cross within trial

The brain-derived neurotrophic factor (BDNF) is involved in the plasticity and development of the central nervous system. Thereby the protein synthesis is highly related to neuronal activity, and its signaling pathways are associated with several substances like, e.g. glucocorticoids, which seem to be able to activate BDNF-Tropomyosin receptor kinase B (TrkB). While there is evidence that acute physical stress can result in advantageous physiological outcomes like an enhanced BDNF level, outcome parameters in response to psychosocial stress are primarily focused on psychological parameters. The existing literature pointing on the impact of acute psychosocial stress on physiological parameters is controversial and differs depending on the species, the stressor used, and the study methodology. It was hypothesized that an acute standardized psychosocial stressor would increase the BDNF level and therefore show beneficial physiological outcome parameters through psychosocial stress. The serum BDNF levels of 32 healthy young males (M = 24.31 years of age, SD = 3.35), who performed the Trier Social Stress Test (TSST), were assessed and compared to a control condition. To prove the stress-generating effect of the TSST, additional cortisol levels were measured. Acute psychosocial stress significantly increased the serum BDNF- and the cortisol-level, whereby no alteration was found during the control. This study expands the rare literature focusing on the effect of an acute standardized psychosocial stressor on the BDNF level in healthy humans, including a control condition. Implications for future studies are being discussed.

48-LB: The Effect of Acute Psychosocial Stress in Adults with Type 1 Diabetes

The effects of acute psychological stress, heart rate variability (HRV), an indicator of autonomic function and glycemic variability (GV) have not been extensively researched in type 1 diabetes (T1D). The aim of this study is to explore the effect of acute psychosocial stress on HRV and GV in people with T1D. Methods: Eleven participants with T1D (33.00 ± 11.25 years) participated in the study. To assess acute mental stress, the subjects 1) participated in the Trier Social Stress Test (TSST); and 2) played competitive video games (Nintendo Switch™). The TSST followed standardized procedures whereby stress was induced asking participants to provide a job talk and arithmetic in front of two judges. Participants played the Mario Kart to go-kart races (10 minutes) and rotated their controllers to untangle the Treasure Chest (10 minutes). Resting HRV and GV were obtained. The subjects wore a continuous glucose monitor and a Zephyr Bioharness™ to record GV and HRV, respectively. Nonparametric, paired samples T-tests were conducted using SPSS 24. Results: During TSST, there were significant differences between the resting and TSST testing period in the sympathetic nervous sympathetic nervous system index (.57 ± 1.33 vs. 1.36 ± 1.40; z = -2.845, respectively; p &amp;lt;.01; and stress index (8.17 ± 3.69 vs. 10.27 ± 5.69; z = -2.578, respectively; p &amp;lt;.05). When subjects were playing video games, there were significant differences in the parasympathetic nervous sympathetic nervous system index (-.09 ± 1.75 vs. -.87 ± 1.05; z = -2.134, respectively; p &amp;lt;.05) compared to a resting period. However, there were no significant differences in GV compared to a resting period in during TSST and playing video game. Conclusion: This study suggests that the TSST induced stress in people with T1D, increased sympathetic activity; however, the TSST did not change glycemic variability. Playing competitive video game did not appear to neither induces stress nor affected glycemic variability. The competitive video game did not cause stress compared to TSST. Disclosure M. Park: None. Y. Song: None. M. Chu: None. M. Sevil: None. N. Hobbs: None. L. Sharp: None. A. Cinar: Research Support; Self; Dexcom, Inc., JDRF. Stock/Shareholder; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk A/S, Tandem Diabetes Care. L.T. Quinn: None. Funding JDRF

A Combination of Magnesium, B Vitamins, Green Tea and Rhodiola Attenuates the Negative Effects of Acute Psychosocial Stress on Subjective State in Adults

Abstract Objectives Magnesium (Mg), and green tea and rhodiola extract supplementation have, in isolation, been shown to improve subjective stress perception and mood responses to acute stress. The combined capacity of these ingredients to confer protective effects during exposure to stress has yet to be evaluated. We tested the hypothesis that a combination of Mg (with B vitamins) + green tea + rhodiola would improve physiological and subjective responses to stress exposure in adults compared to placebo and Mg + B vitamins + green tea or rhodiola in isolation. Methods A double blind, randomised, placebo controlled, parallel group design was employed. 100 moderately stressed (DASS 13–25) adults (mean age = 25.07, SD = 0.65) received oral supplementation of either (i) Mg + B vitamins + green tea + rhodiola; (ii) Mg + B vitamins + rhodiola; (iii) Mg + B vitamins + green tea; or (iv) placebo. After supplementation participants were exposed to the Trier Social Stress Test. Subjective stress (Stress and Arousal Checklist; SACL), mood (Profile of Mood States; POMS) and salivary cortisol responses were collected over 8 hours to ascertain the effects of supplementation on stress responsivity and recovery. Results Analyses demonstrated the superiority of the combined treatment vs the ingredients in isolation and placebo. The combined treatment significantly attenuated subjective stress (SACL), and tension and total mood disturbance (POMS) ratings after acute stress exposure (all P &amp;lt; .05). Effects were found both during the peak stress response and recovery. The salivary cortisol response was unaffected by treatment. Conclusions A combination of Mg + B vitamins + green tea + rhodiola significantly alleviated subjective stress and mood responses to acute stress provocation. This preliminary evidence suggests the capacity of these ingredients in combination to confer protective effects under conditions of stress in adults. Funding Sources Sanofi Aventis.

Stressed connections: cortisol levels following acute psychosocial stress disrupt affiliative mimicry in humans.

Mimicry, and especially spontaneous facial mimicry, is a rudimentary element of social-emotional experience that is well-conserved across numerous species. Although such mimicry is thought to be a relatively automatic process, research indicates that contextual factors can influence mimicry, especially in humans. Here, we extend this work by investigating the effect of acute psychosocial stress on spontaneous facial mimicry. Participants performed a spontaneous facial mimicry task with facial electromyography (fEMG) at baseline and approximately one month later, following an acute psychosocial stressor (Trier Social Stress Test). Results show that the magnitude of the endocrine stress response reduced zygomaticus major reactivity, and specifically spontaneous facial mimicry for positive social stimuli (i.e. smiles). Individuals with higher levels of the stress hormone cortisol showed a more blunted fEMG response to smiles, but not to frowns. Conversely, stress had no effect on corrugator supercilii activation (i.e. frowning to frowns). These findings highlight the importance of the biological stress response system in this basic element of social-emotional experience.

The Effects of Psychosocial Stress and Sex Differences on Cognitive Effort Avoidance

Background: Recent research suggests stress may affect cognitive performance including memory, executive functioning, decision-making, and task-switching. However, it is unknown whether these effects are aversive or advantageous for effort exertion. This experiment aimed to evaluate the effects of acute psychosocial stress on willingness to exert cognitive control processes in a cognitive-effort-based decision-making task.Methods: To test this, 40 participants (20 female) in a within-subject, fully crossed, randomized design, were exposed to both a psychosocial stress induction condition (the Trier Social Stress Test; TSST) and a control condition. Subsequently, they underwent the Demand Selection Task (DST) that tests for participants’ effort aversion by manipulating switch probabilities in a task-switching paradigm. Results and Conclusion: The induction of stress did not lead to significant error or accuracy rates, or significant differences in cognitive effort avoidance. Previous research indicated sex differences in response to stress. However, there is a lack of data on sex differences in the avoidance of demanding cognitive processes. Therefore, we assessed sex differences in the DST and found that women were more likely to avoid cognitive effort, choosing the less cognitively demanding cue more often than men. Limitations: A limitation of this study is the small sample size. Future research should increase the sample size and take individual differences in stress responders, type of stressor, and biases on effort exertion into account.

Acute Stress Improves Concentration Performance

Acute stress can have both detrimental and beneficial effects on cognitive processing, but effects on concentration performance remain unclear. Here, we investigate the effects of acute psychosocial stress on concentration performance and possible underlying physiological and psychological mechanisms. The study sample comprised 47 healthy male participants who were randomly assigned either to a psychosocial stress situation (Trier Social Stress Test) or a neutral control task. Concentration performance was assessed using the d2 Test of Attention before and 30 min after the stress or control task. Salivary cortisol and alpha-amylase were repeatedly measured before and up to 1 hr after stress. We repeatedly assessed state anxiety using the State-Trait Anxiety Inventory and anticipatory cognitive stress appraisal using the Primary Appraisal Secondary Appraisal questionnaire. The stress group showed a significantly stronger improvement of concentration performance compared to the control group (p = .042). Concentration performance improvement was predicted by increased state anxiety (p = .020) and lower cortisol (stress) changes (p = .043). Neither changes in alpha-amylase nor cognitive stress appraisal did relate to concentration performance. Our results show improved concentration performance after acute psychosocial stress induction that was predicted by higher state anxiety increases and lower cortisol increases. This points to a potential modulating role of specific psycho-emotional and physiological factors with opposite effects.

Effects of acute psychosocial stress on the hypothalamic-pituitary-thyroid (HPT) axis in healthy women

ObjectiveThe individual set point of the hypothalamic-pituitary-thyroid (HPT) axis is largely genetically determined. Apart from this genetic predisposition, the HPT axis may also be malleable to environmental demands such as psychosocial stress. Indeed, previous research has indicated that critical life events often precede the onset of autoimmune thyroid diseases, and subtle abnormalities in HPT functioning are present in some patients with stress-related disorders such as depression. However, no studies have investigated whether exposure to psychosocial stress leads to an immediate activation of the HPT axis. MethodsA total of N = 30 healthy women attended two laboratory appointments in a randomized order. An intravenous catheter was inserted at the beginning of each appointment. In the stress session, this was followed by the Trier Social Stress Test (TSST). Plasma samples to determine thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) were taken at baseline and 20, 50, and 110 min after the TSST started. In the control session, participants rested and were instructed to read magazines, while the sampling schedule was maintained. ResultsThere was a significant rise in TSH concentrations in response to the TSST, with a peak observed 20 min after stressor onset, and a steady decline thereafter. No such response was observed in the control session. The TSST did not increase T3 or T4. ConclusionThe finding that acute psychosocial stress is able to elicit a significant increase in TSH is relevant to our understanding of a number of stress-related illnesses presenting with abnormalities of the HPT axis.

The Ethics of Developing New Treatments: A Case Study of the West African Ebola Outbreak and the Use of Randomized Control Trials

Background: Recent research suggests stress may affect cognitive performance including memory, executive functioning, decision-making, and task-switching. However, it is unknown whether these effects are aversive or advantageous for effort exertion. This experiment aimed to evaluate the effects of acute psychosocial stress on willingness to exert cognitive control processes in a cognitive-effort-based decision-making task.Methods: To test this, 40 participants (20 female) in a within-subject, fully crossed, randomized design, were exposed to both a psychosocial stress induction condition (the Trier Social Stress Test; TSST) and a control condition. Subsequently, they underwent the Demand Selection Task (DST) that tests for participants’ effort aversion by manipulating switch probabilities in a task-switching paradigm. Results and Conclusion: The induction of stress did not lead to significant error or accuracy rates, or significant differences in cognitive effort avoidance. Previous research indicated sex differences in response to stress. However, there is a lack of data on sex differences in the avoidance of demanding cognitive processes. Therefore, we assessed sex differences in the DST and found that women were more likely to avoid cognitive effort, choosing the less cognitively demanding cue more often than men. Limitations: A limitation of this study is the small sample size. Future research should increase the sample size and take individual differences in stress responders, type of stressor, and biases on effort exertion into account.

Effects of acute psychosocial stress on the neural correlates of episodic encoding: Item versus associative memory.

Acute stress is known to modulate episodic memory, but little is known about the extent to, and the circumstances under, which stress affects encoding of item vs. inter-item associative information for words of different valences. Furthermore, the precise neuro-cognitive mechanisms underlying stress effects on episodic encoding in humans are largely unknown. To address these questions, in the present study we recorded EEG activity while male participants encoded neutral, negative and positive words, each paired with another word that was always neutral. Immediately before encoding, half of the participants experienced a psychosocial stressor, the Trier Social Stress Test, while the other half underwent a control procedure. Twenty-four hours later, participants completed separate item and associative recognition tests. Pre-learning stress enhanced item recognition accuracy for the positive, but not for the negative words. By contrast, there was no evidence for stress effects on associative recognition. The increase in item recognition was accompanied by a higher familiarity-, but not recollection-, based item retrieval of positive and neutral, but not negative words. Crucially, in the event-related potential (ERP) stress affected the amplitude of the frontal slow wave in general, and the frontal slow wave subsequent memory effect for positive words in specific, and the subsequent memory effect was correlated with cortisol levels after the stress manipulation. Our results suggest that positive words are encoded more elaboratively under stress, leading to a higher likelihood of subsequent item retrieval. An interaction of cortisol with frontal-lobe dependent control processes as well as a shift in attentional biases may contribute to this stress-induced modulation of episodic encoding.

Acute psychosocial stress effects on memory performance: Relevance of age and sex.

In recent decades, there has been a growing interest in investigating the effects of chronic and acute stress on cognitive processes, especially memory performance. However, research focusing on acute stress effects has reported contradictory findings, probably due to the many factors that can moderate this relationship. In addition to factors related to the individual, such as sex and age, other factors, such as the type of memory assessed, can play a critical role in the direction of these effects. This review summarizes the main findings of our research group and others about the effects of acute psychosocial stress on memory performance in young and older people of both sexes, taking into account the type and phase of memory assessed. In our opinion, an approach that addresses individual factors and other factors related to the type of stressor and temporal relationship between exposure to the stressor and performance will contribute to better understanding the mechanisms underlying the complex relationship between acute stress and memory. Finally, some new directions for future studies on this research topic are suggested.

Effects of Acute Psychosocial Stress on Facial Emotion Recognition

Accurate recognition of the emotions of other people is essential for successful human interactions. Previous studies showed inconsistent results of the impact of acute psychosocial stress on emotion recognition. Thus, the present study aimed at investigating the influence of psychosocial stress on the recognition of facial emotional expressions of different valance. Eighty-eight participants were randomly assigned to one of two experimental groups: stress (exposure to the Trier Social Stress Test) and control. Participants of both groups completed a facial emotion recognition test before and after the manipulation. The results demonstrated an enhancement in emotion recognition in the stress group but not in controls. Further analyses revealed that while stress enhanced the accurate recognition of anger, happiness, surprise, and neutral/calmness, it impaired the recognition of fear and had no effect on the recognition of sadness and disgust. The findings are discussed in light of evolutionary assumptions regarding differential processing mechanisms of emotion expressions.