Acute and past subjective stress influence working memory and related neural substrates

Stress, working memory, and academic performance: a neuroscience perspective

The relationship between stress and working memory (WM) is crucial in determining students' academic performance, but the interaction between these factors is not yet fully understood. WM is a key cognitive function that is important for learning academic skills, such as reading, comprehension, problem-solving, and math. Stress may negatively affect cognition, including WM, via various mechanisms; these include the deleterious effect of glucocorticoids and catecholamines on the structure and function of brain regions that are key for WM, such as the prefrontal cortex and hippocampus. This review explores the mechanisms underlying how stress impacts WM and how it can decrease academic performance. It highlights the importance of implementing effective stress-management strategies to protect WM function and improve academic performance.

Mitochondria as a sensor, a central hub and a biological clock in psychological stress-accelerated aging

The theory that oxidative damage caused by mitochondrial free radicals leads to aging has brought mitochondria into the forefront of aging research. Psychological stress that encompasses many different experiences and exposures across the lifespan has been identified as a catalyst for accelerated aging. Mitochondria, known for their dynamic nature and adaptability, function as a highly sensitive stress sensor and central hub in the process of accelerated aging. In this review, we explore how mitochondria as sensors respond to psychological stress and contribute to the molecular processes in accelerated aging by viewing mitochondria as hormonal, mechanosensitive and immune suborganelles. This understanding of the key role played by mitochondria and their close association with accelerated aging helps us to distinguish normal aging from accelerated aging, correct misconceptions in aging studies, and develop strategies such as exercise and mitochondria-targeted nutrients and drugs for slowing down accelerated aging, and also hold promise for prevention and treatment of age-related diseases.

Preventing prefrontal dysfunction by tDCS modulates stress-induced creativity impairment in women: an fNIRS study

Stress is a major external factor threatening creative activity. The study explored whether left-lateralized activation in the dorsolateral prefrontal cortex manipulated through transcranial direct current stimulation could alleviate stress-induced impairment in creativity. Functional near-infrared spectroscopy was used to explore the underlying neural mechanisms. Ninety female participants were randomly assigned to three groups that received stress induction with sham stimulation, stress induction with true stimulation (anode over the left and cathode over the right dorsolateral prefrontal cortex), and control manipulation with sham stimulation, respectively. Participants underwent the stress or control task after the transcranial direct current stimulation manipulation, and then completed the Alternative Uses Task to measure creativity. Behavioral results showed that transcranial direct current stimulation reduced stress responses in heart rate and anxiety. The functional near-infrared spectroscopy results revealed that transcranial direct current stimulation alleviated dysfunction of the prefrontal cortex under stress, as evidenced by higher activation of the dorsolateral prefrontal cortex and frontopolar cortex, as well as stronger inter-hemispheric and intra-hemispheric functional connectivity within the prefrontal cortex. Further analysis demonstrated that the cortical regulatory effect prevented creativity impairment induced by stress. The findings validated the hemispheric asymmetry hypothesis regarding stress and highlighted the potential for brain stimulation to alleviate stress-related mental disorders and enhance creativity.

The Insidious Influence of Stress: An Integrated Model of Stress, Executive Control, and Psychopathology

Although exposure to acute stress undoubtedly contributes to psychopathology, most individuals do not develop psychopathology following stress exposure. To explain this, biological, emotional, and cognitive responses to stress have been implicated, but individual differences in executive control (i.e., top-down control of cognition and behavior) measured in response to stress has only recently emerged as a potential factor contributing to psychopathology. In this review, we introduce a model-the integrated model of stress, executive control, and psychopathology-positing how the impairing effects of acute stress on executive control can contribute to psychopathology. We link to research on biological, emotional, and cognitive processes, all of which can be impacted by executive control, to propose a framework for how poorer executive control under conditions of acute stress can contribute to psychopathology. This integrated model is intended to further our understanding of who is more susceptible to the negative consequences of stress.

Increased sensitivity to unpleasant odor following acute psychological stress

Previous studies have reported increased sensitivity to malodor after acute stress in humans. However, it is unclear whether stress-related "hypersensitivity" to odors depends on odor pleasantness. Forty participants (mean age 19.13 ± 1.14 years, 21 men and 19 women) completed a stress (Trier Social Stress Test, TSST) and a control session in randomized order. Detection threshold to three odors varying in pleasantness (pleasant: β-Citronellol; neutral: 2-Heptanol; unpleasant: 4-Methylpentanoic acid), odor discrimination, odor identification, sensitivity to trigeminal odor, and suprathreshold odor perception were assessed after participants' completion of the stress or the control tasks. Salivary cortisol, subjective stress, and heart rate were assessed throughout the experiment. After TSST, participants showed an increased sensitivity for the unpleasant odor. Moreover, there were correlations between stress-related salivary cortisol and the increased sensitivity for the unpleasant odor (r = 0.32, p = 0.05) and the neutral odor (r = 0.34, p < 0.05). Besides, salivary cortisol response was correlated to the increased odor discrimination performance (Δ stress - control) (r = 0.34, p < 0.05). The post-TSST perceived stress was correlated with decreased odor identification and decreased sensitivity to the unpleasant odor. After stress, participants rated lower pleasantness for β-Citronellol than the control condition. Overall, these results suggest the impact of acute psychological stress on odor sensitivity depends on the odor valence, and that the stress-related cortisol responses may play an important role in this effect.

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.

[Impairment of cognitive functions in patients with chronic thromboembolic pulmonary hypertension before and after surgical treatment]

OBJECTIVE

To study cognitive functions in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and in the long-term after pulmonary thromboendarterectomy and to study factors that negatively affect cognitive status.

MATERIAL AND METHODS

One hundred and twenty-four patients with CTEPH were examined before and 6 months after surgery with an assessment of cognitive impairment using the Mini-Mental State Examination (MMSE). Multivariate regression analysis was used to identify factors affecting the MMSE indicators before and in the long-term postoperative periods.

RESULTS

Initially, patients with CTEPH had a total MMSE score 23.8±1.1. Six months after surgery, the score was 26.1±1.9 (p<0.001). A history of stroke, disability, stress (loss of spouse), and a high Charleson comorbidity index were independent factors affecting MMSE score before surgery. After surgery, the total MMSE score was influenced by a history of stroke, stress (loss of spouse), residual pulmonary hypertension and atrial fibrillation in the early postoperative period.

CONCLUSION

Cognitive impairment in the form of mild dementia was observed in patients with CTEPH before surgery. Six months after the operation, an improvement in cognitive status was revealed, which corresponded to moderate cognitive impairment. At the same time, no complete recovery of cognitive functions was recorded. Patients with CTEPH still experienced the greatest difficulties in the following areas: concentration and counting, memory. A history of stroke, disability, stress (loss of spouse), and a high comorbidity index are associated with a decrease in MMSE scores before surgery. Six months after surgery, MMSE score was affected by a history of stroke, stress (loss of spouse), residual pulmonary hypertension and atrial fibrillation in the early postoperative period.

Does heart rate variability mediate the association between chronic stress, cardiorespiratory fitness, and working memory in young adults?

Young adulthood is a demanding development phase rendering individuals at risk for high levels of stress. While chronic stress may impair working memory maintenance, cardiorespiratory fitness is suggested to have a protective effect. Heart rate variability (HRV) contributes to this cognitive domain, but also retaliates to stress and aerobic exercise. Therefore, the present study investigated the mediating role of resting HRV on the association between chronic stress, cardiorespiratory fitness, and working memory maintenance in young healthy adults. Healthy participants (N = 115, 48% female) aged 18-35 years (M = 24.1, SD = 3.8) completed the Åstrand test on a bicycle ergometer to estimate maximal oxygen consumption [ V ̇ O 2 max $$ \dot{\mathrm{V}}{\mathrm{O}}_{2\max } $$ (ml/min/kg)]. In addition, working memory maintenance was assessed using the modified Sternberg task with low (three items) and high cognitive load (six items). Using electrocardiography, HRV was recorded and the LF/HF ratio was extracted for mediation analyses. Path analysis revealed that cardiorespiratory fitness was significantly associated with accuracy on high cognitive load trials (β = 0.19, p = 0.035), but not on trials with low cognitive load. Perceived levels of chronic stress failed to show a significant association with working memory maintenance, independently of cognitive load. The pattern of results remained unchanged after introduction of HRV as a mediator (β = 0.18, p = 0.045). In conclusion, higher cardiorespiratory fitness is associated with better maintenance of verbal information in working memory. However, this association cannot be explained by vagal influences on memory processing driven by the autonomic nervous system.

Perceived Past and Current COVID-19-Stressors, Coping Strategies and Psychological Health among University Students: A Mediated-Moderated Model

The COVID-19-pandemic entailed abrupt/long-lasting changes in university students' lives, resulting in growing stress and stress-related outcomes. Although nowadays the pre-pandemic-life is gradually re-establishing, past-COVID-19-stressful experiences and strategies adopted to adjust to this condition may significantly impact students' current experiences. Therefore, the development of research exploring the complex interplay between perceived past/present COVID-19-related experiences, coping strategies, and psychological health currently reported by students is needed. This study simultaneously tests the associations between Past-COVID-19-stressors and Current-COVID-19-stressors as moderated by Coping Strategies and the associations between Past-COVID-19-stressors and Psychological Symptoms as mediated by Current-COVID-19-stressors. A mediated-moderated model was tested on 355 university students. COVID-19-Student-Stress-Questionnaire (CSSQ) was used to assess COVID-19-stressors. Two CSSQ-versions were used, one of which was adjusted to assess Past-COVID-19-stressors recalled from previous restrictive pandemic phases. Coping-Orientation-to-Problem-Experienced-New-Italian-Version and Symptom-Checklist-90-Revised were used to assess, respectively, Coping Strategies and Psychological Symptoms. Findings confirmed the hypothesized Mediated-Moderated Model. The effects of Past-COVID-19-stressors on Current-COVID-19-stressors were moderated by Coping Strategies, and the effects of Past-COVID-19-stressors on Psychological Symptoms were mediated by Current-COVID-19-stressors. Unique psychopathological risk profiles deriving from the interplay between specific past/present stressors and coping strategies were found. Researchers and clinicians can use these findings to develop updated research and timely evidence-based interventions fostering students' adjustment in the current period. Future research should further explore the impact of the complex interplay between perceived past/present COVID-19-related experiences and individual characteristics on psychological health conditions reported by people in the aftermath of the COVID-19 pandemic.

The effect of perceived stress on cognition is mediated by personality and the underlying neural mechanism

Perceived stress impairs cognitive function across the adult lifespan, but the extent to which cognition decline is variable across individuals. Individual differences in the stress response are described as personality traits. Substantial individual differences in the magnitude of cognitive impairment that is induced by short-term perceived stress are poorly understood. The present study tested the hypothesis that the relationship between short-term perceived stress and different aspects of cognition is mediated by personality traits. The study included 1066 participants with behavior and neuroimaging data from the Human Connectome Project after excluding individuals with missing variables. In the result, the parallel multiple mediation model demonstrated that the influence of perceived stress on the total and crystalized cognition is mainly mediated by neuroticism (indirect effect = -0.04, p < 0.05) and conscientiousness (indirect effect = 0.05, p < 0.05) in adults. Cortical thickness value (n = 1066) of the right superior frontal gyrus (SFG) showed not only positive correlations with short-term perceived stress and neuroticism, but negative associations with cognition. The chain mediation model found that the right SFG and neuroticism play a small but significant chain mediating effect between stress and total cognition. The strength of the resting-state functional connectivity (n = 968) between the left orbitofrontal cortex versus the left superior medial frontal cortex was positively correlated with crystallized cognition and negatively associated with conscientiousness. These results extend previous findings by the impacts of short-term perceived stress on cognitive function is mediated by neuroticism and the right SFG was the underlying neural mechanism.

Multi-timepoint pattern analysis: Influence of personality and behavior on decoding context-dependent brain connectivity dynamics

Behavioral traits are rarely considered in task‐evoked functional magnetic resonance imaging (MRI) studies, yet these traits can affect how an individual engages with the task, and thus lead to heterogeneity in task‐evoked brain responses. We aimed to investigate whether interindividual variation in behavior associates with the accuracy of predicting task‐evoked changes in the dynamics of functional brain connectivity measured with functional MRI. We developed a novel method called multi‐timepoint pattern analysis (MTPA), in which binary logistic regression classifiers were trained to distinguish rest from each of 7 tasks (i.e., social cognition, working memory, language, relational, motor, gambling, emotion) based on functional connectivity dynamics measured in 1,000 healthy adults. We found that connectivity dynamics for multiple pairs of large‐scale networks enabled individual classification between task and rest with accuracies exceeding 70%, with the most discriminatory connections relatively unique to each task. Crucially, interindividual variation in classification accuracy significantly associated with several behavioral, cognition and task performance measures. Classification between task and rest was generally more accurate for individuals with higher intelligence and task performance. Additionally, for some of the tasks, classification accuracy improved with lower perceived stress, lower aggression, higher alertness, and greater endurance. We conclude that heterogeneous dynamic adaptations of functional brain networks to changing cognitive demands can be reliably captured as linearly separable patterns by MTPA. Future studies should account for interindividual variation in behavior when investigating context‐dependent dynamic functional connectivity.

Transcranial direct current stimulation of bilateral dorsolateral prefrontal cortex eliminates creativity impairment induced by acute stress

The creativity impairment under acute stress may be closely related to the down-regulation of the prefrontal cortex function caused by stress-related neurotransmitters and hormones. In the current study, we explored whether transcranial direct current stimulation (tDCS) over bilateral dorsolateral prefrontal cortex (DLPFC) eliminated stress-induced creativity impairment and the potential mechanism from the perspective of stress response recovery. Seventy participants were randomly allocated to a group undergoing the activation of right DLPFC and the deactivation of left DLPFC (R+L-; N = 35), and a group of sham stimulation (sham; N = 35). Participants received tDCS after the stress induction, and then completed the Alternative Uses Task (AUT) and the Remote Association Task (RAT) during the stimulation. The stress response was indicated using heart rate, cortisol, and emotion changes. Results showed that R+L- stimulation facilitated the recovery of anxious state compared to sham stimulation. We also found that the decreased value of AUT scores after stress in the R+L- group was significantly lower than that in the sham group. Moreover, further analysis revealed state anxiety mediated the effect of tDCS on the flexibility component of the AUT. We concluded that bilateral tDCS over the DLPFC is efficient in alleviating stress-induced creativity impairment, which may correlate with greater recovery of state anxiety. Our findings provide causal evidence for the neurophysiological mechanisms by which stress affects creativity, as well as clinical suggestions for stress-related psychiatric disorders prevention and intervention.

Psychosocial stress has weaker than expected effects on episodic memory and related cognitive abilities: A meta-analysis

The impact of stress on episodic memory and related cognitive abilities is well documented in both animal and human literature. However, it is unclear whether the same cognitive effects result from all forms of stress - in particular psychosocial stress. This review systematically explored the effects of psychosocial stress on episodic memory and associated cognitive abilities. PubMed, PsycInfo, and Web of Science databases were searched. Fifty-one studies were identified and compared based on the timing of stress induction. A small positive effect of post-learning psychosocial stress with a long retention interval was shown. No other effects of psychosocial stress were seen. Re-analysis of previous meta-analyses also showed no significant effect of psychosocial stress on episodic memory, highlighting potentially different effects between stressor types. Psychosocial stress also had a moderately different effect when emotional vs. neutral stimuli were compared. Finally, psychosocial stress also decreased performance on executive function, but not working memory tasks. Our findings demonstrate that psychosocial stress may not have the clear effects on episodic memory previously ascribed to it.

Current psychosocial stress, childhood trauma and cognition in patients with schizophrenia and healthy participants

BACKGROUND

Cognitive difficulties are experienced frequently in schizophrenia (SZ) and are strongly predictive of functional outcome. Although severity of cognitive difficulties has been robustly associated with early life adversity, whether and how they are affected by current stress is unknown. The present study investigated whether acute stress reactivity as measured by heart rate and mood changes predict cognitive performance in patients with schizophrenia and healthy individuals, and whether this is moderated by diagnosis and previous childhood trauma exposure.

METHODS

One hundred and four patients with schizophrenia and 207 healthy participants were administered a battery of tasks assessing cognitive performance after psychosocial stress induction (Trier Social Stress Test; TSST). Mood states (Profile of Mood States; POMS) and heart rate were assessed at baseline, immediately before, and after the TSST.

RESULTS

Both healthy participants and patients showed increases in POMS Tension and Total Mood Disturbance scores between Time Point 2 (pre-TSST) and Time Point 3 (post-TSST). These changes were not associated with variation in cognition. Although childhood trauma exposure was associated with higher stress reactivity and poorer cognitive function in all participants, childhood trauma did not moderate the association between stress reactivity and cognition. Neither was diagnosis a moderator of this relationship.

DISCUSSION

These findings suggest that while chronic stress exposure explains significant variation in cognition, acute stress reactivity (measured by changes in Tension and Total Mood Disturbance) did not. In the context of broader developmental processes, we conclude that stressful events that occur earlier in development, and with greater chronicity, are likely to be more strongly associated with cognitive variation than acute transient stressors experienced in adulthood.

Acute Psychosocial Stress Increases Cognitive-Effort Avoidance

Adverse effects following acute stress are traditionally thought to reflect functional impairments of central executive-dependent cognitive-control processes. However, recent evidence demonstrates that cognitive-control application is perceived as effortful and aversive, indicating that stress-related decrements in cognitive performance could denote decreased motivation to expend effort instead. To investigate this hypothesis, we tested 40 young, healthy individuals (20 female, 20 male) under both stress and control conditions in a 2-day study that had a within-subjects design. Cognitive-effort avoidance was assessed using the demand-selection task, in which participants chose between performing low-demand and high-demand variants of a task-switching paradigm. We found that acute stress indeed increased participants' preference for less demanding behavior, whereas task-switching performance remained intact. Additional Bayesian and multiverse analyses confirmed the robustness of this effect. Our findings provide novel insights into how stressful experiences shape behavior by modulating our motivation to employ cognitive control.

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.

Stress effects on cognitive function in patients with major depressive disorder: Does childhood trauma play a role?

Impaired cognitive functioning constitutes an important symptom of major depressive disorder (MDD), potentially associated with elevated cortisol levels. Adverse childhood experiences (ACE) enhance the risk for MDD and can contribute to disturbances in the stress systems, including cortisol and cognitive functions. In healthy participants, cortisol administration as well as acute stress can affect cognitive performance. In the current study, we tested cognitive performance in MDD patients with (N = 32) and without (N = 52) ACE and healthy participants with (N = 22) and without (N = 37) ACE after psychosocial stress induction (Trier Social Stress Test, TSST) and a control condition (Placebo-TSST). MDD predicted lower performance in verbal learning and both selective and sustained attention, while ACE predicted lower performance in psychomotoric speed and working memory. There were no interaction effects of MDD and ACE. After stress, MDD patients were more likely to show lower performance in working memory as well as in selective and sustained attention compared with participants without MDD. Individuals with ACE were more likely to show lower performance in verbal memory after stress compared with individuals without ACE. Our results indicate negative effects of MDD and ACE on distinct cognitive domains. Furthermore, MDD and/or ACE seem to enhance susceptibility for stress-related cognitive impairments.

Distinct Effects of Social Stress on Working Memory in Obsessive-Compulsive Disorder

Stress might exaggerate the compulsion and impair the working memory of patients with obsessive-compulsive disorder (OCD). This study evaluated the effect of stress on the cognitive neural processing of working memory in OCD and its clinical significance using a "number calculation working memory" task. Thirty-eight patients and 55 gender- and education-matched healthy controls were examined. Stress impaired the performance of the manipulation task in patients. Healthy controls showed less engagement of the medial prefrontal cortex and striatum during the task under stress versus less stress, which was absent in the patients with OCD. The diagnosis × stress interaction effect was significant in the right fusiform, supplementary motor area, precentral cortex and caudate. The failure of suppression of the medial prefrontal cortex and striatum and stress-related hyperactivation in the right fusiform, supplementary motor area, precentral cortex, and caudate might be an OCD-related psychopathological and neural response to stress.

Associations between brain activity and endogenous and exogenous cortisol - A systematic review

To arrive at a coherent understanding of the relation between glucocorticoids and the human brain, we systematically reviewed the literature for studies examining the associations between endogenous or exogenous cortisol and human brain function. Higher levels of endogenous cortisol during psychological stress were related to increased activity in the middle temporal gyrus and perigenual anterior cingulate cortex (ACC), decreased activity in the ventromedial prefrontal cortex, and altered function (i.e., mixed findings, increased or decreased) in the amygdala, hippocampus and inferior frontal gyrus. Moreover, endogenous cortisol response to psychological stress was related to increased activity in the inferior temporal gyrus and altered function in the amygdala during emotional tasks that followed psychological stress. Exogenous cortisol administration was related to increased activity in the postcentral gyrus, superior frontal gyrus and ACC, and altered function in the amygdala and hippocampus during conditioning, emotional and reward-processing tasks after cortisol administration. These findings were in line with those from animal studies on amygdala activity during and after stress.

Hydrocortisone decreases metacognitive efficiency independent of perceived stress

It is well established that acute stress produces negative effects on high level cognitive functions. However, these effects could be due to the physiological components of the stress response (among which cortisol secretion is prominent), to its psychological concomitants (the thoughts generated by the stressor) or to any combination of those. Our study shows for the first time that the typical cortisol response to stress is sufficient to impair metacognition, that is the ability to monitor one's own performance in a task. In a pharmacological protocol, we administered either 20 mg hydrocortisone or placebo to 46 male participants, and measured their subjective perception of stress, their performance in a perceptual task, and their metacognitive ability. We found that hydrocortisone selectively impaired metacognitive ability, without affecting task performance or creating a subjective state of stress. In other words, the single physiological response of stress produces a net effect on metacognition. These results inform our basic understanding of the physiological bases of metacognition. They are also relevant for applied or clinical research about situations involving stress, anxiety, depression, or simply cortisol use.

Working Memory Performance Under Stress

Acute stress and chronic stress change the physiology and function of the individual. As one facet, stress and its neuroendocrine correlates - with glucocorticoids in particular - modulate memory in a concerted action. With respect to working memory, impairing effects of acute stress and increased levels of glucocorticoids could be expected, but empirical evidence on moderating effects of cortisol on working memory is ambiguous in human studies. In the current study, we thus aimed to investigate cortisol stress responses and memory performance. Older men and women (32 men, 43 women, aged 61-67 years) underwent the Trier Social Stress Test (TSST) and performed the 2-back task before and after exposure to acute stress. In line with theoretical assumptions, we found that higher cortisol stress responses led to a decline of working memory performance in men. However, the opposite was evident for women, who appeared to benefit from higher stress responses. This effect was evident for accuracy, but not for reaction time. In conclusion, cortisol might mediate working memory alterations with stress in a sex-specific manner in older people. Possible mechanisms and causes for these sex differences put a focus on endocrine changes in the aging population that might lead to differential effects across the lifespan.

Stress & executive functioning: A review considering moderating factors

A multitude of studies investigating the effects of stress on cognition has produced an inconsistent picture on whether - and under which conditions - stress has advantageous or disadvantageous effects on executive functions (EF). This review provides a short introduction to the concept of stress and its neurobiology, before discussing the need to consider moderating factors in the association between stress and EF. Three core domains are described and discussed in relation to the interplay between stress and cognition: the influence of different paradigms on physiological stress reactivity, individual differences in demographic and biological factors, and task-related features of cognitive tasks. Although some moderating variables such as the endocrine stress response have frequently been considered in single studies, no attempt of a holistic overview has been made so far. Therefore, we propose a more nuanced and systematic framework to study the effects of stress on executive functioning, comprising a holistic overview from the induction of stress, via biological mechanisms and interactions with individual differences, to the influence of stress on cognitive performance.

Feasibility and predictors of change of narrative exposure therapy for displaced populations: a repeated measures design

BACKGROUND

Displaced victims of interpersonal violence, such as refugees, asylum seekers, and victims of sexual exploitation, are growing in numbers and are often suffering from a post-traumatic stress disorder (PTSD). At the same time, these victims are known to benefit less from trauma-focused therapy (TFT) and to be less compliant to treatment. The objective of this paper is to describe the rationale and research protocol of an ongoing trial that aims to evaluate different variables that might influence the feasibility of TFT for the study population. Specifically, perceived daily stress, emotion regulation, and mood are investigated as predictors of change in PTSD symptoms during a trauma-focused therapy (narrative exposure therapy (NET)). The feasibility of administering measures tapping these constructs repeatedly during treatment will also be evaluated.

METHODS/DESIGN

Using an observational treatment design, 80 displaced victims of interpersonal violence will be measured before, during, and after partaking in NET. Several questionnaires tapping PTSD plus the aforementioned possible predictors of PTSD change will be administered: Post-traumatic Stress Disorder Checklist-5, Perceived Stress Scale, Difficulties in Emotion Regulation Scale-18 (pre-test, post-test, and follow-up),subscale impulsivity of the Difficulties in Emotion Regulation Scale-18, Perceived Stress Scale short version, Primary Care Post-traumatic Stress Disorder and a single Mood item (each session). Multilevel modelling will be used to examine the relation between the possible predictors and treatment outcome.

DISCUSSION

The present study is the first to examine the interplay of facilitating and interfering factors possibly impacting treatment feasibility and effectiveness in displaced victims of interpersonal violence with PTSD receiving NET, using repeated measures. The current study can help to improve future treatment based on individual characteristics.

TRIAL REGISTRATION

Netherlands Trial Register: NTR7353, retrospectively registered. Date of registration: July 11, 2018.

Amygdala and prefrontal cortex activity varies with individual differences in the emotional response to psychosocial stress

Stress elicits a variety of psychophysiological responses that show large interindividual variability. Determining the neural mechanisms that mediate individual differences in the emotional response to stress would provide new insight that would have important implications for understanding stress-related disorders. Therefore, the present study examined individual differences in the relationship between brain activity and the emotional response to stress. In the largest stress study to date, 239 participants completed the Montreal Imaging Stress Task (MIST) while heart rate, skin conductance response (SCR), cortisol, self-reported stress, and blood oxygen level dependent (BOLD) functional MRI (fMRI) signal responses were measured. The relationship between differential responses (heart rate, SCR, cortisol, and self-reported stress) and differential BOLD fMRI data was analyzed. Dorsolateral prefrontal cortex (PFC), dorsomedial PFC, ventromedial PFC, and amygdala activity varied with the behavioral response (i.e., SCR and self-reported stress). These results suggest the PFC and amygdala support processes that are important for the expression and regulation of the emotional response to stress, and that stress-related PFC and amygdala activity underlie interindividual variability in peripheral physiologic measures of the stress response. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Determining the mechanisms through which recent life stress predicts working memory impairments: precision or capacity?

Prior research has found that recent life stress exposure is related to poorer working memory performance, but it remains unclear which aspects of working memory are related to stress. To address this important issue, we examined the extent to which recent life stress exposure was associated with working memory capacity (i.e., the number of items that can be held in working memory) and working memory precision (i.e., the quality of representations of items held within working memory) in a sample of 260 healthy young adults (M_age= 19.95 years old; range = 18-33). Recent life stress exposure and working memory were assessed with the Stress and Adversity Inventory for Daily Stress (Daily STRAIN) and color wheel task, respectively. We found that recent life stress was selectively associated with lower working memory capacity; moreover, the association of recent life stress with capacity was significantly stronger in magnitude than the non-significant association of recent life stress with precision. These associations were robust while controlling for potential confounds, including demographic factors, negative affect, and cumulative lifetime stress exposure. These results thus suggest that stress-related degradations in working memory capacity may help explain how recent life stress exposure affects working memory performance.

Subjective and physiological stress measurement in a multiple sclerosis sample and the relation with executive functions performance

In multiple sclerosis (MS), hypothalamic-pituitary-adrenal (HPA) axis functioning may be dysregulated due to the high cortisol levels involved in the disease activity. HPA axis dysregulation can affect cognitive performance, including executive functions. This study aimed to evaluate hair cortisol concentration and perceived stress as well as verify the association with the performance of executive function in both individuals diagnosed with MS and control individuals. Hair cortisol concentration and perceived stress were evaluated and their association with the performance of healthy individuals (n = 33) and those with MS (n = 64), most of them with remitting-relapsing multiple sclerosis (RRMS) assessed using the Expanded Disability Status Scale (EDSS). Instruments that were employed to measure perceived stress and health aspects included the Behavioral Assessment Dysexecutive Syndrome, Wisconsin Card Sorting Test, Stroop Test, and Perceived Stress Scale. No significant statistical difference was found in the comparison of means among the groups; however, an association was found when using statistical correlation tests between cortisol and cognitive performance in the clinical group (r = 0.31, p = 0.10). Further, an absence of correlations with perceived stress measure was noted. It was possible to observe interaction between group factors and low level of cortisol and problem-solving/cognitive flexibility in the MS group. The results indicated that stress measures used in the present study seem to influence the performance of inhibitory control and problem-solving/cognitive flexibility, the latter with low levels of cortisol in individuals with MS. We suggest studies that examine different measures of physiological stress and characteristics of the disease such as more time of stress.

Psychophysiological stress response and memory in borderline personality disorder

Background: Previously, we found that patients with borderline personality disorder (BPD) but not healthy controls (HC) showed improved memory retrieval after hydrocortisone administration. Objective: In this study, we examined whether increases in endogenous cortisol after psychosocial stress are associated with memory function in patients with BPD and in healthy individuals. Methods: We recruited 49 female patients with BPD and 49 female HC. All participants were exposed to a psychosocial stressor, the Trier Social Stress Test (TSST) and a control condition (Placebo (P-)TSST) in randomized order. Salivary cortisol, alpha amylase (sAA) and blood pressure were measured in response to stress. Subsequently, we examined free recall of a previously learned word list, autobiographical memory, and working memory. Results: We found a stress*time*group interaction effect for the cortisol response and for sAA to stress, which is mainly triggered by a slightly different increase in cortisol between groups from pre to post TSST. Furthermore, BPD patients showed a less pronounced increase in diastolic blood pressure compared to HC after stress. There was no effect of stress on memory performance in any tests, either in healthy controls or in patients with BPD. Conclusion: Our results suggest a slightly blunted response of the HPA axis and the sympathetic nervous system to stress in BPD compared to healthy women. In contrast to hydrocortisone administration, psychosocial stress did not improve memory retrieval in BPD patients. This might be explained by lower cortisol concentrations and parallel increases in norepinephrine and negative affect after stress.