Acute Exposure to the Cold Pressor Stress Impairs Working Memory Functions: An Electrophysiological Study

Brief slow-paced breathing improves working memory, mood, and stress in college students

BACKGROUND

Few studies have examined the effects of brief focused breathing techniques. This study investigated the impact of brief slow-paced breathing (SPB) with a longer exhalation on working memory and perceived mood, stress, and arousal.

DESIGN

Between-subjects experimental design.

METHODS

Participants (139 undergraduates, 69% female) were randomized to a one-time SPB session or a mind-wandering active control condition. The participants completed the OSPAN working memory task and state measures of mood, stress, and arousal at three time points: baseline, post-manipulation, and post-task.

RESULTS

OSPAN performance improved in the experimental group. Mood improved in the experimental group but decreased in the control group from baseline to post-manipulation and then decreased in both conditions after completing the OSPAN task. Stress decreased in the experimental group from baseline to post-manipulation and was significantly different from the control group at the post-manipulation time point. Stress then increased from post-manipulation to post-task in both conditions. Arousal decreased in both conditions from baseline to post-manipulation but then increased from post-manipulation to post-task.

CONCLUSIONS

The current results demonstrate that a brief SPB session with longer exhalation improved working memory and temporarily improved mood and stress thus providing a just-in-time intervention to help individuals cope with stress-inducing conditions.

Effects of stress on cognitive performance

Stress remains a pervasive challenge in modern life, exerting significant impacts on cognitive performance and overall well-being by triggering release of stress hormones like adrenaline and cortisol. It has profound implications for education, work performance, and everyday life, impacting cognitive performance, health outcomes, and social relationships. It does this by impacting memory, attention and focus, informed decision-making, developmental and cognitive performance, work and educational performance, genetic and epigenetic influence, and public health. When a stressor is perceived, the hypothalamus in the brain signals the pituitary gland to release adrenocorticotropic hormone, hence adrenaline is quickly released into the bloodstream, causing immediate physiological changes and thus releasing cortisol gradually to help maintain the body's response to stress over a longer period through the hypothalamic-pituitary-adrenal and sympathetic-adrenomedullar axis. The impacts can be short-term or long-term focusing on the working memory, pre-frontal cortex, amygdala, and hippocampus. By recognizing these implications and implementing targeted interventions, we can foster environments that support resilience, optimize performance, and enhance overall well-being across diverse contexts. This chapter also highlighted some mitigation strategies to reduce stress-related activities and improve cognitive performance, such as cognitive-behavioral therapy, mindfulness-based stress reduction, healthy lifestyle adoption, pet therapy, time management and prioritization, and workplace interventions.

EEG Evidence of Acute Stress Enhancing Inhibition Control by Increasing Attention

OBJECTIVE

Research about the impact of acute stress on inhibitory control remains a contentious topic, with no consensus reached thus far. This study aims to investigate the effects of acute stress on an individual's inhibitory control abilities and to elucidate the underlying neural mechanisms by analyzing resting state electroencephalogram (EEG) data.

METHODS

We recruited 32 male college students through participant recruitment information to undergo within-subject experiments under stress and non-stress conditions. Physiological indicators (cortisol and heart rate), self-report questionnaires, and behavioral data from the Stroop task were collected before, during, and after the experiment. Additionally, a five-minute eyes closed resting state EEG data collection was conducted during the Stroop task before.

RESULTS

(1) Acute stress led to a reduction in the conflict effect during the participants' Stroop task in individuals. (2) Stress resulted in an increase in the power of the beta in the resting state EEG. (3) Acute stress caused an increase in the duration of class D and an increase in the transition probabilities from classes C and B to class D in the microstates of the resting state EEG. (4) Acute stress leads to an increase in beta power values in individuals' resting state EEGs, which is significantly negatively correlated with the reduction of the conflict effect in the Stroop task under stress.

CONCLUSIONS

Acute stress can enhance individuals' attentional level, thereby promoting inhibitory control performance.

Acute Stress Does Not Affect Motor Imagery Ability in Young, Healthy Participants: A Randomized Trial

Motor imagery (MI) is the mental representation of a movement without its execution. It activates internal representations of the movement without external stimulus through different memory-related processes. Although acute stress is frequent in the population and affects supraspinal structures essential for memory functionality, it is still unknown how that stress affects MI capacity and temporal congruence (TC) between execution and movement imagination. This study aimed to discover how acute stress may influence MI capacity and TC in the subscales of internal and external visual imagery and kinesthetic imagery. A double-blind, randomized trial was conducted. Sixty-two young, healthy subjects (mean age = 20.65 [2.54]; 39 females and 23 males) unfamiliar with the assessment and uses of MI were recruited. Participants were assigned by stratified randomization to the stress group or the control group. Stress was induced by the Maastricht Acute Stress Test (MAST), while the control group performed the MAST control protocol. MI capacity and TC were assessed before (t1) and after (t2) MAST stress or control using the Movement Imagery Questionnaire-3 (MIQ-3). Electrodermal activity and heart rate variability were further recorded as control variables to assess stress induction. Thirty subjects in the stress group and 26 subjects in the control group were analyzed. No significant group differences were observed when comparing MI capacity or TC in any subscales. These findings suggest that acute stress does not significantly affect MI capacity or TC in young, healthy, non-experienced MI subjects. MI could thus be a relevant helpful technique in stressful situations.

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.

Effects and mechanisms of extremely cold environment on body response after trauma

With the outbreak of the Ukrainian crisis, extremely cold environment warfare has once again become the focus of international attention. People exposed to extremely cold environments may suffer from cold damage, further aggravate trauma, trigger high disability and mortality rates, and even cause serious sequelae. To declare the effects and mechanisms of the extremely cold environment on the body after trauma, this paper reviews, firstly, physiological reaction of human body in an extremely cold environment. Then, the post-traumatic body response in an extremely cold environment was introduced, and finally, the sequelae of trauma in extremely cold environment was further summarized in the paper. The results indicated that extremely cold environment can cause a series of damage to the body, especially the body after trauma. The extremely cold factor is a double-edged sword, showing a favorable and unfavorable side in different aspects. Moreover, in addition to the trauma suffered by the body, the subsequent sequelae such as cognitive dysfunction, anxiety, depression and even post-traumatic stress disorder may also be induced. The paper summarizes the human body's physiological response in an extremely cold environment, and declares the effects and mechanisms of the extremely cold environment on the body after trauma, which may provide a theoretical basis for effectively improving the level of combat trauma treatment in extremely cold regions.

The effect of courage on stress: The mediating mechanism of behavioral inhibition and behavioral activation in high-risk occupations

Employees in high-risk occupations are exposed to tremendous work acute stress or prolonged stress disorders that are likely to undermine the health and organizational effectiveness. Based on positive psychology, courage which refers to behavioral approach despite the experience of fear could buffer the negative effects on stress. However, there is little known about the mechanisms by which courage decreases the risk of stress. Motivational systems may play an underlying role in this process, as behavioral inhibition system (BIS) is inhibited and behavioral activation system (BAS) is evoked by risk or threat. The current study aimed to examine the mediating effects of behavioral inhibition and activation on the relationship between courage and stress in the high-risk occupations. This study recruited 1,761 high-risk employees aged from 18 to 27 (M = 19.32; SD = 4.14) with a cluster sampling method who completed Courage Measure (CM), the BIS/BAS Scales and the Psychological Stress Evaluation Test (PSET). The correlation and mediation analyses examined the inter-variable correlations as well as the underlying mechanism between courage and stress. The results support the hypothesis and reveal that the behavioral inhibition mediates the association between courage and stress (Bindirect = −0.02, p < 0. 01, 95%CI = −0.03 to −0.003). The behavioral activation of fun seeking mediates the association between courage and stress as well (Bindirect = −0.04, p < 0. 01, 95%CI = −0.058 to −0.029). These findings suggest that behavioral inhibition and activation of fun seeking play imperative mechanism underpinning the buffering effect of courage on stress. Other theoretical and applied implications for desensitizing stress in the high-risk occupations are discussed.