The effects of acute stress on episodic memory: A meta-analysis and integrative review

Memory Under Stress: From Adaptation to Disorder

Stressful events are ubiquitous in everyday life. Exposure to these stressors initiates the temporally orchestrated release of a multitude of hormones, peptides, and neurotransmitters that target brain areas that have been critically implicated in learning and memory. This review summarizes recent insights on the profound impact of stress on 4 fundamental processes of memory: memory formation, memory contextualization, memory retrieval, and memory flexibility. Stress mediators instigate dynamic alterations in these processes, thereby facilitating efficient responding under stress and the creation of a decontextualized memory representation that can effectively aid coping with novel future threats. While they are generally adaptive, the same stress-related changes may contribute to the rigid behaviors, uncontrollable intrusions, and generalized fear responding seen in anxiety disorders and posttraumatic stress disorder. Drawing on recent discoveries in cognitive neuroscience and psychiatry, this review discusses how stress-induced alterations in memory processes can simultaneously foster adaptation to stressors and fuel psychopathology. The transition from adaptive to maladaptive changes in the impact of stress on memory hinges on the nuanced interplay of stressor characteristics and individual predispositions. Thus, taking individual differences in the cognitive response to stressors into account is essential for any successful treatment of stress-related mental disorders.

Determining the influence of an intervention of stress management on medical students' levels of psychophysiological stress: the protocol of the PROMESS-Stress clinical trial

BACKGROUND

Medical students face highly competitive stressful situations throughout their curriculum, which can lead to elevated stress levels and a major decline in quality of life, well-being, learning abilities, and health. It is crucial to assist medical students in coping with these stressful situations during their curriculum.

METHODS

The PROMESS-Stress clinical trial aims to support future healthcare professionals by enhancing their abilities to manage stressful situations. The support will be provided through a 3-session stress management program. Each session will include an individual meeting between a PROMESS-Stress expert and a medical student. To reduce stress levels and enhance coping mechanisms, these sessions will focus on establishing personalized advice and goals. The present protocol is designed to assess the influence of this program on forty-five undergraduate medical students (4th and 5th-year) of the Lyon-Est Faculty of Medicine (Claude Bernard University Lyon 1, France). Assessments of psychological and physiological stress variables will be conducted before and during the intervention. At the end of the 3rd session the student's levels of satisfaction will be assessed. The primary outcome will be changes in scores on the Perceived Stress Scale (PSS), while secondary outcomes will provide a detailed characterization of the intervention's effects on stress coping behaviors, psychological and physiological stress variables. Exploratory outcomes will provide information regarding the student's level of satisfaction and will determine the moderators of the program's efficacy. Data will be analyzed according to the intention-to-treat principle and presented in accordance with the CONSORT Guidelines. Ethical approval has been obtained by the Institutional Review Board (IRB: 2023-07-04-02) and all the procedures will be performed in adherence to the Helsinki declaration. Results from this study will be presented at scientific conferences and in peer-reviewed scientific journals.

DISCUSSION

Results will provide valuable insights into the program's efficacy in reducing stress and improving coping abilities. If its efficacy is proven, PROMESS-Stress could become an integral and sustainable part of medical education, fostering a healthier and more resilient future for healthcare professionals. This manuscript follows the SPIRIT guidelines (Additional files 1 & 6).

TRIAL REGISTRATION

ClinicalTrials.gov: NCT06295133; retrospectively registered.

The recovery and retraction of memories of abuse: a scoping review

People who claim to have been abused sometimes retract these claims at a later point in time. Research on these so-called 'retractors' might provide critical insights into the processes involved in the recovery and retraction of traumatic memories. However, the literature on this topic is highly diverse in terms of, for example, methodology. Hence, the aim of the current scoping review was to amass the available literature on retractors and identify key themes. We identified 17 articles on the topic of retractors ranging from empirical studies to critical commentaries. A central theme that arose from the literature was the influence of therapy in the recovery of potentially false memories. That is, retractors noted that therapists frequently believed that they harboured unconscious repressed memories of abuse which had to be recovered during therapy. Furthermore, retractors repudiated their claims of abuse for various reasons such as physical evidence implying that their memory was false. Also, retraction took longer that the initial recovery of memories of abuse. Finally, after recantation, retractors' memories varied considerably in terms of belief and recollection of the traumatic event with some accounts qualifying as nonbelieved memories. This review offers critical knowledge of a rather understudied population providing further insight in how traumatic events can sometimes be misremembered.

Remembering what did not happen: the role of hypnosis in memory recall and false memories formation

Memory recall is subject to errors that can lead to the formation of false memories. Several factors affect memory processes, such as attention deficits or emotional distress. Additionally, cardiovascular diseases may lead to cognitive decline and memory loss, also increasing the occurrence of false events recall. Hypnosis has proved to affect the autonomic nervous system, positively impacting the cardiovascular response. Hypnosis has also been suggested as a tool to enhance memory and autobiographical events recall in both healthy and unhealthy individuals; however, this approach has led to several controversies. Particularly, the employment of hypnosis in autobiographical recall (hypnotic regression) has been accused of favoring the creation of false memories, leading to therapeutic fallacy. In this paper, we review the current literature on the mechanisms behind the creation of false memories and the role played by hypnosis in memory enhancement and false memory recall. The evidence here collected suggests that cardiovascular diseases affect brain health contributing to cognitive decline and memory impairments, also increasing the occurrence of false memories. Hypnosis induces an increase in parasympathetic activity and a decrease in sympathetic activity, suggesting a potential role in preventing some cardiovascular diseases, such as hypertension, which in turn may improve brain health. Additionally, hypnosis has been shown to have some effectiveness in enhancing memory functions, although contradictory findings reported by several studies make it difficult to draw proper conclusions. Hypnotic regression and guided imagery should be used with caution as they may unintentionally lead to false memory recall. Nevertheless, further studies are required to better understand the effects of hypnosis on the brain and the heart and how it can be used to enhance memory, especially in people with cognitive decline.

Acute stress differentially influences risky decision-making processes by sex: A hierarchical bayesian analysis

How does stress influence our decision-making? Although numerous studies have attempted to answer this question, their results have been inconsistent-presumably due to methodological heterogeneity. Drawing on cumulative prospect theory, we examined how acute stress influenced risky decision-making. To this end, we randomly assigned 147 participants to an acute stress induction or control condition and subsequently assessed participants' risky decision-making. We found that stress increased risky decision-making overall, but more importantly, that stress exerted multiple effects on risky decision-making processes that differed between male and female participants. For female participants, relative to the control condition, stress produced a pattern of decision-making characterized by risk seeking with respect to gains, slightly reduced loss aversion, accurate outcome probability assessment, and greater choice stochasticity. For male participants, stress, relative to the control condition, produced to a pattern of decision-making characterized by very low loss aversion and poorer outcome probability assessment. These results suggest that some of the heterogeneity in existing literature may be explainable by task differences in risk type, risk amount, and outcome certainties, and further that these effects will differ by sex. In short, stress changes how we make decisions, and it does so differently by sex.

Memory under pressure: The impact of acute stress across different memory tasks

In the present study, we aimed to investigate how acute stress exerts its heterogeneous effects. Based on biophysical network models, we hypothesized that acute stress would improve occipital-mediated ultra-short-term and to a lesser degree affect occipital- and frontal-mediated short-term and working, and impairs hippocampal-mediated long-term memory processes and their respective behavioral measures. To test this, 111 healthy individuals (57 female) underwent both the Trier Social Stress Test (TSST) and a control test. Immediately afterward, participants' performance was measured in four memory tasks (Rapid Serial Visual Presentation, RSVP, Match-to-Sample, MTS, N-Back, NB and Free-Recall, FR tasks). TSST exposure seems to impair long-term memory (ACFR; β = -1.50 ± 0.62; when free recall was tested approx. 80 minutes after initial encoding, immediately after the TSST), and working memory (ACNB; β= -0.42 ± 0.20 %) but did not affect ultra-short-term (ACRSVP; β = -0.03 ± 0.31 %) and short-term (ACMTS; β=-0.18 ± 0.31 %) memory accuracies (ACs). Interestingly, TSST exposure increased the exploratory included measure of response times in MTS (RTMTS; β =16.42 ± 7.18 msec) and impaired T1 detection in the RSVP (ACT1; β=-0.48 ± 0.22 %) tasks. Contrary to the hypothesis, TSST exposure did not have the hypothesized effects on the memory processes. Instead, TSST exposure appeared to affect secondary behavioral indicators of motivation or task instruction adherence.

The effects of a single bout of high intensity exercise on stress reactivity, mind wandering, and lecture comprehension in young adults

Post-secondary students experience acute stressors daily. Acute stress has been associated with poor cognitive and learning outcomes. Prior work has demonstrated a single bout of exercise can attenuate acute stress responses. The present study examined the effects of a single 30-minute bout of high intensity aerobic exercise on multidimensional stress reactivity and learning-related outcomes. Forty participants were randomized to either engaging in an exercise bout or seated rest. Participants were then exposed to the Trier Social Stress Test followed by a 20-minute video lecture. The video lecture contained embedded mind wandering probes. Acute exercise did not attenuate stress responses, however promoted greater on-task behaviour (i.e., less mind wandering) and improved lecture comprehension scores. Notably, state anxiety was positively associated with mind wandering and mind wandering was negatively associated with lecture comprehension. Collectively, examining the role of acute interventions that reduce state anxiety may promote favourable learning outcomes in young adults.

Associations among perceived stress and mindfulness on post-concussion cognitive and mental health outcomes in young adults with a concussion history

BACKGROUND

Despite evidence suggesting perceived stress negatively impacts post-concussion outcomes and that mindfulness may improve that relationship, research has not investigated those connections.

METHODS

This cross-sectional, observational study included 80 young adults with a concussion history who completed a single study visit including the following measures: 1) demographics and concussion, mental health, and mindfulness histories; 2) perceived stress [Perceived Stress Scale (PSS-10)]; 3) mindfulness [Five Facet Mindfulness Questionnaire (FFMQ)]; and 4) post-concussion cognitive and mental health outcomes - neurocognitive performance (CNS Vital Signs), psychological symptoms [Brief Symptom Inventory-18 (BSI-18)], and QOL [Patient-Reported Outcomes Measurement Information System (PROMIS®)]. First, separate regression models determined the association among perceived stress and post-concussion cognitive and mental health outcomes. Second, linear regression models determined the association among mindfulness and post-concussion cognitive and mental health outcomes. Third, to test the moderation effect, models included a perceived stress and mindfulness interaction term.

RESULTS

Higher perceived stress was significantly associated with higher psychological symptoms (p < 0.001) and lower QOL (p < 0.05). Higher mindfulness was significantly associated with lower psychological symptoms (p < 0.001) and higher QOL (p < 0.05). No moderation models were significant.

CONCLUSION

Future research is necessary to further understand mechanisms impacting post-concussion interventions aimed to improve outcomes and life post-concussion.

Identifying the most effective acute stress induction methods for producing SAM- and HPA-related physiological responses: a meta-analysis

BACKGROUND AND OBJECTIVES

Laboratory-based stress inductions are commonly used to elicit acute stress but vary widely in their procedures and effectiveness. We compared the effects of stress induction techniques on measures of two major biological stress systems: the early sympathetic-adrenal-medullary (SAM) and the delayed hypothalamic-pituitary-adrenal (HPA) axis response.

DESIGN

A review and meta-analysis to examine the relationship between stress induction techniques on cardiorespiratory and salivary measures of SAM and HPA system activity.

METHODS

A systematic literature search identified 245 reports and 700 effects.

RESULTS

The overall effect of stress induction techniques on the stress response was moderate (Fisher's zr = 0.44), inducing stronger SAM-related (zr = 0.48) versus HPA-related (zr = 0.37) responses. Three factors moderated these associations: the stress system examined (SAM vs HPA), the specific stress induction technique employed (e.g., Cold Pressor), the physiological sampling time relative to the stress induction, and participant sex. Loud music elicited the most robust SAM-related effects, whereas combined stress inductions elicited the most robust HPA-related effects. Men showed stronger stress responses than women.

CONCLUSIONS

Stress induction techniques variably elicit SAM - and HPA-related responses. Results recommend specific induction techniques for targeting stress systems, highlighting the importance of carefully selecting methodologies in laboratory contexts.

Acute immune system activation exerts time-dependent effects on inhibitory control: Results of both a randomized controlled experiment of influenza vaccination and a systematic review and meta-analysis - ISPNE 2024 Dirk Hellhammer Award

Although coming down with an illness or receiving a vaccine are both common experiences, the influence of such acute immune system activations on cognitive processes, such as inhibitory control, has received relatively little attention. We addressed that issue by assessing the effects of acute immune system activation on inhibitory control in a randomized controlled experiment, and by conducting a meta-analysis of similar studies in humans. In our experiment, we found-somewhat surprisingly-that influenza vaccination improved performance on both of our inhibitory control outcomes (i.e., stop-signal reaction times and flanker interference effects). At the meta-analytic level, we found that at a short delay (1.5-4 hours post-injection) between immune activation and inhibitory control assessment, such activation impaired multiple forms of inhibitory control, whereas after a longer delay (e.g., > 18 hours post-injection), such activation improved inhibitory control-consistent with our experiment. Moreover, proinflammatory cytokine activity predicted poorer interference control but better response inhibition, even with a long delay between injection and testing. Together, these results highlight nuanced, time-dependent, and-perhaps-multiple-mechanism-driven effects of acute immune system activity on inhibitory control.

Contextual memory bias in emotional events: Neurobiological correlates and depression risk

BACKGROUND

Contextual memory loss of emotional events plays a critical role in depression psychopathology. Individuals with depression, clinical or subclinical, exhibit enhanced and impaired memory for emotionally negative stimuli and context in an event, respectively. This suggests that contextual encoding may fail because of attentional interference caused by concurrent negative stimuli, possibly leading to contextual memory loss as a depression risk. Amygdala-prefrontal connectivity and cortisol may underlie the mechanism; however, the relationships remain unknown.

METHODS

One hundred twenty participants, including 34 with subclinical depression, underwent behavioral tasks, functional magnetic resonance imaging (fMRI) scans, and saliva collection. Encoding and 24 h later recollection performance of visuoperceptual/spatial/temporal context in a series of events, where fearful (vs. neutral) faces appeared, were measured via contextual memory tasks. Overgeneral autobiographical memory (OGM), a more remote form of contextual memory loss, was also assessed via the Autobiographical Memory Test. Amygdala connectivity was measured by fMRI during attentional interference by fearful (vs. neutral) faces to differentiate selective attention from encoding. Basal cortisol levels were assayed through saliva collected at encoding during the visit day and across 2 consecutive days in the following week (12 time points in total). We explored whether contextual memory encoding failure would explain depressive symptoms through OGM under possible moderation of amygdala connectivity and cortisol.

RESULTS

In individuals with subclinical depression compared to those without, fearful faces disturbed memory encoding of the visuoperceptual context rather than 24 h later recollection, while neutral faces in their temporal proximity contrastingly augmented it. The more the contextual memory encoding bias (fearful vs. neutral) intensified, the more the amygdala's functional connectivity with the ventromedial prefrontal cortex (vmPFC) weakened. Higher total cortisol output tended to be correlated with poorer 24-h later recollection of the temporal context. Moderated mediation effects of the amygdala-vmPFC connectivity and cortisol were not significant; however, contextual encoding bias explained depressive symptoms through negatively valenced OGM.

CONCLUSIONS

Negative stimuli appearing in an event might impair memory encoding of the visuoperceptual context under attentional interference, represented as weakened amygdala-vmPFC connectivity implicated in emotion-related attentional dysregulation. Conversely, negative stimuli might enhance temporally proximal visuoperceptual encoding after their disappearance. Contextual encoding bias could explain the overgeneralization (or lower coherence) of autobiographical memory and increase the risk of depression. The possible role of cortisol in recollecting the context of emotional events over time warrants further investigation.

The impact of momentary stress on autobiographical memory recall in a self-efficacy intervention

Recalling positive autobiographical memories has been associated with various positive psychological outcomes, including enhanced mental well-being and self-efficacy. Given the known impact of stress on cognitive functioning, we investigated how momentary stress affects the repeated recall of selected autobiographical mastery memories (e.g., memories of overcoming challenges) in a training to enhance self-efficacy. During this one-week digital training, participants (N = 54) were asked to recall mastery memories, and we assessed their momentary stress levels, memory vividness, and recall feasibility using Ecological Momentary Assessment. Analyses using linear mixed-effects models showed that participants reported greater difficulty and less vividness in recalling self-efficacy memories during moments of increased stress, whereas feeling relaxed facilitated recall feasibility and vividness. Though participants who experienced less recall difficulty appeared to benefit more, recall difficulty and vividness did not significantly moderate improvements in self-efficacy. While replication in a larger, more diverse sample is indicated, our findings underscore the importance of considering momentary affect in memory-based mental health interventions. Effects may be particularly pronounced when interventions are applied during the early stages of stress, when stress levels are still relatively low, aligning with the strategy of Just-in-Time Adaptive Interventions. Our study also highlights the potential benefits of combining memory recall practices with relaxation-promoting interventions to enhance mental health outcomes.

Neurobiological stress markers in educational research: A systematic review of physiological insights in health science education

BACKGROUND

Traditional self-reported measures in health science education often overlook the physiological processes underlying cognitive and emotional responses.

PURPOSE

This review aims to analyze the frequency, sensitivity, and utility of physiological markers in understanding cognitive and emotional dynamics in learning environments.

METHODS

A systematic PubMed search identified 156 records, with 13 studies meeting inclusion criteria. Markers analyzed included heart rate (HR), heart rate variability (HRV), cortisol, alpha-amylase, testosterone, s-IgA, blood pressure, oxygen saturation, and respiratory rate.

MAIN FINDINGS

HR and HRV were sensitive to educational stressors. Cortisol and alpha-amylase showed mixed results, while testosterone and s-IgA showed limited utility in directly assessing stress responses. No consistent link was found between any marker and immediate learning success.

CONCLUSION

Physiological markers in learning environments can offer valuable insights into emotional and cognitive dynamics but should not be misconstrued as direct indicators of learning outcomes.

Update on "Emotion and autobiographical memory": 14 years of advances in understanding functions, constructions, and consequences

Holland and Kensinger (2010) reviewed the literature on "Emotion and autobiographical memory." They focused on two broad ways that emotions influence memory: (1) emotion during an event influences how the event is remembered, and (2) emotion and emotional goals during memory retrieval influence how past events are remembered. We begin by providing a brief update on the key points from that review. Holland and Kensinger (2010) also had noted a number of important avenues for future work. Here, we describe what has been learned about the functions of autobiographical memory and their reconstructive nature. Relatedly, we review more recent research on memory reconstruction in the context of visual perspective shifts, counterfactual thinking, nostalgia, and morality. This research has emphasized the reciprocal nature of the interactions between emotion and autobiographical memory: Not only do emotions influence memory, memories influence emotions. Next, we discuss advances that have been made in understanding the reciprocal relations between stress, mood, and autobiographical memory. Finally, we discuss the research that is situating emotional autobiographical memories within a social framework, providing a bedrock for collective memories. Despite the many advances of the past 14 years, many open questions remain; throughout the review we note domains in which we hope to see advances over the next decades.

High and low current perceived stress associated with enhanced emotional mnemonic discrimination

Stress can have profound impacts on memory. However, the directionality of stress effects on memory varies widely across studies, some showing enhancement while others showing impairment. This variability has been attributed to the Yerkes-Dodson Law, which proposes a U-shaped pattern such that too little or too much stress may be associated with cognitive dysfunction. The impact of stress on memory may also depend on what aspects of memory are being measured (e.g., emotional content, gist vs. detail) and how stress is measured (e.g., physiological measures, self-report). Here, we aimed to examine how self-reported perceived stress in the current moment was associated with memory performance. We used an emotional memory task designed to tap into potential gist versus detail trade-offs of stress impacting memory (e.g., target recognition, lure discrimination). Participants (ages 18-35) reported their current level of perceived stress. We replicated prior work showing impaired emotional relative to neutral lure discrimination in young adults in support of a gist versus detail trade-off in emotional memory. However, those with low and high current perceived stress showed better emotional lure discrimination compared to those with moderate current perceived stress. These results are in line with the Yerkes-Dodson Law but suggest that the directionality of the impact of stress on memory may depend on the type of memory measured. Low and high current perceived stress was associated with greater detailed memory, especially for emotional information, which may be maladaptive given gist vs. detail trade-offs in emotional memory.

The mediational role of hearing acuity in the association between personality and memory: Evidence from the health and retirement study and the English Longitudinal Study of Ageing

OBJECTIVES

Personality traits (i.e., the enduring patterns of thoughts, feelings, and behaviors) are associated with cognition across adulthood. There is interest in identifying potential mechanisms to explain this association, but none has focused on sensory function. Therefore, the present study examined whether an objective measure of hearing acuity mediates the association between personality and memory.

METHODS

Participants were from the Health and Retirement Study (HRS, N = 5497, 60 % women, Mean age = 65.66, SD = 9.00) and the English Longitudinal Study of Ageing (ELSA, N = 4706, 57 % women, Mean age = 64.47, SD = 7.59). In the HRS, participants had data on personality and demographic variables in 2012/2014, hearing acuity in 2016/2018, and memory in 2020. In ELSA, participants had data on personality and demographic variables measured in 2010/2011, hearing acuity in 2014/2015, and memory in 2018/2019.

RESULTS

In both HRS and ELSA, higher hearing acuity partially mediated the association between lower neuroticism (4 % and 5 % proportion effect mediated), higher conscientiousness (6 % and 15 %) and higher openness (3 % and 7 %) and better memory performances at follow-up.

CONCLUSIONS

The present study provides novel evidence that hearing acuity mediates the association between personality and cognition.

Stress enhances memory for previously encoded events depending on stressor recall

Stressful events are typically well remembered, but their effects on memory for surrounding neutral events and the underlying mechanisms remain less clear. We hypothesized that stress would enhance memory for events surrounding the stressor, contingent on the memory of the stressor itself. Additionally, we predicted that memory for neutral events would be modulated by pairing them with stressor-related cues. To test these hypotheses, 122 healthy participants encoded a series of images before and after experiencing a stressful or control episode. During encoding, images were preceded by cues from stressor or control contexts. Memory for the stress or control episode and the encoded images was tested 24 h later. Our results showed enhanced memory prioritization, reflected in better memory for central versus peripheral features, for the stressful compared to the control episode. Exposure to the stressful episode further enhanced memory for neutral images preceding the stressor. However, this memory boost occurred only in participants with enhanced memory prioritization for the stressor. Memory for stimuli encoded after the stressor remained unaffected, and there was no evidence for the proposed cueing mechanism. These findings indicate that stressful events enhance memory consolidation only when these events themselves are distinctly represented in memory.

Emotional, physiological, biochemical, and behavioral responses to acute stress and uncertainty in military personnel

Stress carries diverse implications for perceptual, cognitive, and affective functions. One population particularly susceptible to acute stress-induced cognitive changes are individuals with high-stress jobs (e.g., military personnel). These individuals are often tasked with maintaining peak cognitive performance, including memory, spatial navigation, and decision-making under threatening and uncertain conditions. Previous research has separately examined decision-making under conditions of stress or uncertainty (i.e., ambiguous discrimination between friends and foes). However, questions remain about how operationally relevant stress impacts memory encoding and recall, or spatial learning, as well as how uncertainty may impact decision-making during stress. To address this gap, we examined the influence of a military-relevant emotional stressor on a series of cognitive tasks including recognition memory task (RMT), spatial orienting task (SOT), and shoot/don't shoot decision making (DMT). To examine the effects of uncertainty and stress we varied the stimulus clarity in the DMT. We utilized threat of shock (TOS) as a high-stakes outcome for decision errors. TOS increased sympathetic arousal but did not affect subjective emotional or HPA responses. TOS influenced decision times and confidence ratings in the DMT, but not response sensitivity or response bias. DMT performance varied by stimulus clarity (uncertainty) but did not differ between stress conditions. TOS did not influence recognition memory or spatial orienting. In sum, high levels of stress and uncertainty characterize military operations, yet stress experienced in military contexts can be difficult to induce in laboratory settings. We discuss several avenues for future research, including methodological considerations to better assess the magnitude and specificity of emotional stress-induction techniques in Soldiers.

A chloro substituted organoselenium mitigates stress-associated memory impairment and hippocampal glutamatergic function in a repeated Forced Swim Stress Model

Stress is triggered by a threatening event that alters the regulation of emotion, behavior, and cognition. The effects of stress on memory in animal models are well-documented. Firstly, this study aimed to determine whether the repeated forced swim stress (FSS) protocol induces memory impairment comparable to single prolonged stress (SPS) in the Y-maze test. The second objective was to evaluate whether (p-ClPhSe)2 pretreatment mitigates stress-associated memory impairment and hippocampal glutamatergic neurotransmission in FSS-exposed mice. Mice subjected to FSS and SPS protocols reduced time spent in the novel arm of the Y-maze test compared to the control group, with no observed changes in locomotor or exploratory behavior. (p-ClPhSe)2 was administered to mice at a dose of 5 mg/kg, 30 min before the first forced swimming session on days 1 and 2. Mice underwent a Y-maze test, after which they were euthanized, and hippocampal samples were collected. (p-ClPhSe)2 pretreatment protected against the reduction in time spent in the novel arm by mice subjected to FSS. Repeated FSS exposure increased hippocampal protein levels of NMDAR subunits 2A, 2B, and EAAT1 compared to controls. (p-ClPhSe)2 pretreatment prevented this increase. In conclusion, (p-ClPhSe)2 mitigated stress-induced memory impairment in FSS-exposed mice, normalizing hippocampal NMDAR 2A, 2B, and EAAT1 protein levels.

The impact of threat of shock on memory for threat-irrelevant information: Evidence for a role of reduced semantic organization

Research into the effects of acute anxiety on episodic memory has produced inconsistent findings, particularly for threat-neutral information. In two experiments, we tested the hypothesis that anxiety induced by threat of shock can interfere with the use of semantic-organizational processes that benefit memory. In Experiment 1, participants viewed and freely recalled two lists of semantically unrelated neutral words, one encoded in a threatening context (threat blocks) and one encoded without threat (safe blocks). As predicted, significantly fewer words were recalled during threat than safe blocks. Moreover, free recall patterns following threat blocks showed lower levels of semantic organization as assessed using a "path length" measurement that considers the semantic distance between pairs of consecutively recalled words. Both effects unexpectedly interacted with block order, such that they primarily reflected improved recall and increased semantic organization from the first to the second block in participants who received the threat block first. Experiment 2 used semantically related word lists to reduce potential impacts of task experience on semantic organization. Free recall was again less accurate and showed longer (less organized) path lengths for threat than safe blocks, and the path length effect no longer interacted with block order. Moreover, threat-induced changes to path lengths emerged as a mediator of the relation between physiological effects of threat (increased skin conductance) and reduced subsequent memory. These data point to semantic control processes as an understudied determinant of when and how acute anxiety impacts episodic memory.

Transfer from goal-directed behavior to stimulus-response habits and its modulation by acute stress in individuals with risky gaming behavior

Habitual responses towards addiction-related cues play a relevant role in the development and maintenance of addictions. Such automatic responses may be more likely under stress, as stress has been shown to induce a shift from goal-directed to habitual behavior. The current study investigated these mechanisms in risky gaming behavior. Individuals with risky gaming behavior (n = 68), as established by a structured clinical interview, and a matched control group (n = 67) completed a Pavlovian-to-Instrumental Transfer (PIT) paradigm with gaming-related cues and rewards. After the Pavlovian training, participants underwent a stress (Trier Social Stress Test) or control condition before performing the instrumental training and the transfer phase of the PIT paradigm. To assess habitual behavior, the gaming-related rewards were devalued after half of the transfer phase. In both groups, gaming-related cues enhanced the choice of the gaming-related reward and this gaming PIT effect was reduced, however, not eliminated by the devaluation. Unexpectedly, stress did not significantly increase responding for the gaming-related reward in participants aware of the stimulus-outcome associations, however seemed to enhance habitual responding in unaware participants. Our findings underline the relevance of gaming-related cues in triggering habitual responses, which may undermine attempts to change a problematic gaming behavior.

What the Acute Stress Response Suggests about Memory

Research suggests that stress has immediate and long-term effects on attention and memory. Rather than disrupting memory formation and consolidation, acute stress has been shown to shift attention processes resulting in a tradeoff between prioritized and nonprioritized information. Both arousal and stress result in cognitive and neurobiological shifts that often support memory formation. When an acute stressor occurs, it can distort immediate attentional focus, increasing processing for high-priority features while reducing processing for extraneous features. The downstream cognitive consequences for this shift in attention are better memory for some features and poorer memory for others when compared to conditions of low stress. However, individual differences (e.g., sex, age, basal stress response, and stress reactivity) all impact the relationship between the acute stress response and memory. Although acute stress generally benefits memory formation, we suggest that forgetting and later recovery of stressful memories can better be understood by examining factors that influence the subjective experience of stress and stress reactivity.

Beyond Repressed Memory: Current Alternative Solutions to the Controversy

Debates surrounding the origin of recovered memories of child abuse have traditionally focused on two conflicting arguments, namely that these memories are either false memories or instances of repressed memories (i.e., reflecting the idea that people can unconsciously block traumatic autobiographical experiences and eventually regain access). While scientific evidence for the first is clearly established, the second is the subject of a controversy in the academic, clinical, and legal fields. This controversy rages on today. In this introductory article to our topic "Beyond Repressed Memory: Current Alternative Solutions to the Controversy," we present alternative and more parsimonious explanations for repressed memories that we sorted into three categories: cognitive, motivational, and biological factors. Our aim is to provide a timely overview to help clinical and legal professionals, academics, and the general public to move beyond the idea that traumatic memories can be unconsciously repressed.

Clinically established early Parkinson's disease patients do not show impaired use of priors in conditions of perceptual uncertainty

The ability to use past learned experiences to guide decisions is an important component of adaptive behavior, especially when decision-making is performed under time pressure or when perceptual information is unreliable. Previous studies using visual discrimination tasks have shown that this prior-informed decision-making ability is impaired in Parkinson's disease (PD), but the mechanisms underlying this deficit and the precise impact of dopaminergic denervation within cortico-basal circuits remain unclear. To shed light on this problem, we evaluated prior-informed decision-making under various conditions of perceptual uncertainty in a sample of 13 clinically established early PD patients, and compared behavioral performance with healthy control (HC) subjects matched in age, sex and education. PD patients and HC subjects performed a random dot motion task in which they had to decide the net direction (leftward vs. rightward) of a field of moving dots and communicate their choices through manual button presses. We manipulated prior knowledge by modulating the probability of occurrence of leftward vs. rightward motion stimuli between blocks of trials, and by explicitly giving these probabilities to subjects at the beginning of each block. We further manipulated stimulus discriminability by varying the proportion of dots moving coherently in the signal direction and speed-accuracy instructions. PD patients used choice probabilities to guide perceptual decisions in both speed and accuracy conditions, and their performance did not significantly differ from that of HC subjects. An additional analysis of the data with the diffusion decision model confirmed this conclusion. These results suggest that the impaired use of priors during visual discrimination observed at more advanced stages of PD is independent of dopaminergic denervation, though additional studies with larger sample sizes are needed to more firmly establish this conclusion.

The influence of time of day on memory recognition for faces

Time of day can alter memory performance in general. Its influence on memory recognition performance for faces, which is important for daily encounters with new persons or testimonies, has not been investigated yet. Importantly, high levels of the stress hormone cortisol impair memory recognition, in particular for emotional material. However, some studies also reported high cortisol levels to enhance memory recognition. Since cortisol levels in the morning are usually higher than in the evening, time of day might also influence recognition performance. In this pre-registered study with a two-day design, 51 healthy men encoded pictures of male and female faces with distinct emotional expressions on day one around noon. Memory for the faces was retrieved two days later at two consecutive testing times either in the morning (high and moderately increased endogenous cortisol levels) or in the evening (low endogenous cortisol levels). Additionally, alertness as well as salivary cortisol levels at the different timepoints was assessed. Cortisol levels were significantly higher in the morning compared to the evening group as expected, while both groups did not differ in alertness. Familiarity ratings for female stimuli were significantly better when participants were tested during moderately increased endogenous cortisol levels in the morning than during low endogenous cortisol levels in the evening, a pattern which was previously also observed for stressed versus non-stressed participants. In addition, cortisol levels during that time in the morning were positively correlated with the recollection of face stimuli in general. Thus, recognition memory performance may depend on the time of day and as well as on stimulus type, such as the difference of male and female faces. Most importantly, the results suggest that cortisol may be meaningful and worth investigating when studying the effects of time of day on memory performance. This research offers both, insights into daily encounters as well as legally relevant domains as for instance testimonies.

Decision-making under stress: A psychological and neurobiological integrative model

Understanding the impact of stress on cognitive processes, particularly decision-making, is crucial as it underpins behaviors essential for survival. However, research in this domain has yielded disparate results, with inconsistencies evident across stress-induction paradigms and drug administration protocols designed to investigate specific stress pathways or neuromodulators. Building upon empirical studies, this research identifies a multifaceted matrix of variables contributing to the divergent findings. This matrix encompasses factors such as the temporal proximity between stressors and decision tasks, the nature of stressors and decision contexts, individual characteristics including psychobiological profiles and affective states at the time of decision-making and even cultural influences. In response to these complexities, we propose a comprehensive model that integrates these relevant factors and their intricate interplay to elucidate the mechanisms governing decision-making during stressful events. By synthesizing these insights, our model not only refines existing paradigms but also provides a framework for future study designs, offering avenues for theoretical advancements and translational developments in the field of stress's impact on cognitive functions. This research contributes to a deeper understanding of the nuanced relationship between stress and decision-making, ultimately advancing our knowledge of cognitive processes under challenging conditions.

Acute Stress Effects on Statistical Learning and Episodic Memory

Stress is widely considered to negatively impact hippocampal function, thus impairing episodic memory. However, the hippocampus is not merely the seat of episodic memory. Rather, it also (via distinct circuitry) supports statistical learning. On the basis of rodent work suggesting that stress may impair the hippocampal pathway involved in episodic memory while sparing or enhancing the pathway involved in statistical learning, we developed a behavioral experiment to investigate the effects of acute stress on both episodic memory and statistical learning in humans. Participants were randomly assigned to one of three conditions: stress (socially evaluated cold pressor) immediately before learning, stress ∼15 min before learning, or no stress. In the learning task, participants viewed a series of trial-unique scenes (allowing for episodic encoding of each image) in which certain scene categories reliably followed one another (allowing for statistical learning of associations between paired categories). Memory was assessed 24 hr later to isolate stress effects on encoding/learning rather than retrieval. We found modest support for our hypothesis that acute stress can amplify statistical learning: Only participants stressed ∼15 min in advance exhibited reliable evidence of learning across multiple measures. Furthermore, stress-induced cortisol levels predicted statistical learning retention 24 hr later. In contrast, episodic memory did not differ by stress condition, although we did find preliminary evidence that acute stress promoted memory for statistically predictable information and attenuated competition between statistical and episodic encoding. Together, these findings provide initial insights into how stress may differentially modulate learning processes within the hippocampus.

How emotions shape memory? The moderating effect of healthy emotionality on eyewitness testimony

The influence of emotions on memory is a significant topic in the psychology of eyewitness testimony. However, conflicting results have arisen, possibly due to varying approaches and methodologies across studies. These discrepancies might also arise from inadequate consideration of individual differences in emotionality. Therefore, this study aims to analyze the moderating effect of healthy emotionality on the relationship between emotion and memory of criminal events. The results of our laboratory experiment (N = 150) conducted with VR technology indicate that eyewitnesses of crimes, unlike observers of neutral events, recall details concerning the perpetrators' actions immediately preceding the crime act better. Notably, individuals with lower scores on a scale measuring healthy emotionality (ESQ) demonstrate enhanced recollection for these details. At the same time, emotionality plays no significant role in recollection in repeated measurement, as well as in remembering the neutral event. The emotions experienced during crime observation appear to hinder the recollection of perpetrator appearance and behavior unrelated to the crime. These findings are discussed in light of the adaptive role of negative emotions in detecting danger and preparing for unpleasant stimuli.

Impaired free recall of neutral but not negative material tested 105 min after cortisol administration

Pharmacological studies have consistently shown memory retrieval impairment after administration of cortisol, particularly pronounced for emotional laboratory material (i.e. list of emotional words). However, it is unclear how pharmacological elevation of cortisol affects memory retrieval of ecologically-relevant emotional material (i.e. similar to a newspaper article about an emotional event). In the present study, we aimed to explore whether cortisol administration affects the recall of ecologically-relevant emotional and neutral material, and when memory retrieval occurs after a longer delay (105 min). In this double-blind, pseudo-randomized, placebo-control study, 79 participants learned a negative text and a neutral text. Twenty-four hours later, they were administrated either 10 mg of hydrocortisone or placebo. After 105 min, participants engaged in free recall of both texts. The group with cortisol administration showed significantly reduced free recall compared to the placebo group. Interestingly, this memory retrieval impairment was driven by significantly lower recall after cortisol vs. placebo administration for neutral texts, but not negative texts. The current finding suggests that cortisol administration impairs neutral ecologically-relevant material while leaving emotional material unaffected. These divergent findings, compared to existing literature, emphasize the necessity of employing more ecologically validated material to gain a more comprehensive understanding of the intricate interplay between cortisol administration and memory for ecological material.

Integrating and fragmenting memories under stress and alcohol

Stress can powerfully influence the way we form memories, particularly the extent to which they are integrated or situated within an underlying spatiotemporal and broader knowledge architecture. These different representations in turn have significant consequences for the way we use these memories to guide later behavior. Puzzlingly, although stress has historically been argued to promote fragmentation, leading to disjoint memory representations, more recent work suggests that stress can also facilitate memory binding and integration. Understanding the circumstances under which stress fosters integration will be key to resolving this discrepancy and unpacking the mechanisms by which stress can shape later behavior. Here, we examine memory integration at multiple levels: linking together the content of an individual experience, threading associations between related but distinct events, and binding an experience into a pre-existing schema or sense of causal structure. We discuss neural and cognitive mechanisms underlying each form of integration as well as findings regarding how stress, aversive learning, and negative affect can modulate each. In this analysis, we uncover that stress can indeed promote each level of integration. We also show how memory integration may apply to understanding effects of alcohol, highlighting extant clinical and preclinical findings and opportunities for further investigation. Finally, we consider the implications of integration and fragmentation for later memory-guided behavior, and the importance of understanding which type of memory representation is potentiated in order to design appropriate interventions.

New Insights on Expert Opinion About Eyewitness Memory Research

Experimental psychologists investigating eyewitness memory have periodically gathered their thoughts on a variety of eyewitness memory phenomena. Courts and other stakeholders of eyewitness research rely on the expert opinions reflected in these surveys to make informed decisions. However, the last survey of this sort was published more than 20 years ago, and the science of eyewitness memory has developed since that time. Stakeholders need a current database of expert opinions to make informed decisions. In this article, we provide that update. We surveyed 76 scientists for their opinions on eyewitness memory phenomena. We compared these current expert opinions to expert opinions from the past several decades. We found that experts today share many of the same opinions as experts in the past and have more nuanced thoughts about two issues. Experts in the past endorsed the idea that confidence is weakly related to accuracy, but experts today acknowledge the potential diagnostic value of initial confidence collected from a properly administered lineup. In addition, experts in the past may have favored sequential over simultaneous lineup presentation, but experts today are divided on this issue. We believe this new survey will prove useful to the court and to other stakeholders of eyewitness research.

Class I histone deacetylases inhibition reverses memory impairment induced by acute stress in mice

While chronic stress induces learning and memory impairments, acute stress may facilitate or prevent memory consolidation depending on whether it occurs during the learning event or before it, respectively. On the other hand, it has been shown that histone acetylation regulates long-term memory formation. This study aimed to evaluate the effect of two inhibitors of class I histone deacetylases (HDACs), 4-phenylbutyrate (PB) and IN14 (100 mg/kg/day, ip for 2 days), on memory performance in mice exposed to a single 15-min forced swimming stress session. Plasma corticosterone levels were determined 30 minutes after acute swim stress in one group of mice. In another experimental series, independent groups of mice were trained in one of three different memory tasks: Object recognition test, Elevated T maze, and Buried food location test. Subsequently, the hippocampi were removed to perform ELISA assays for histone deacetylase 2 (HDAC2) expression. Acute stress induced an increase in plasma corticosterone levels, as well as hippocampal HDAC2 content, along with an impaired performance in memory tests. Moreover, PB and IN14 treatment prevented memory loss in stressed mice. These findings suggest that HDAC2 is involved in acute stress-induced cognitive impairment. None of the drugs improved memory in non-stressed animals, indicating that HDACs inhibitors are not cognitive boosters, but rather potentially useful drugs for mitigating memory deficits.

Representational formats of human memory traces

Neural representations are internal brain states that constitute the brain's model of the external world or some of its features. In the presence of sensory input, a representation may reflect various properties of this input. When perceptual information is no longer available, the brain can still activate representations of previously experienced episodes due to the formation of memory traces. In this review, we aim at characterizing the nature of neural memory representations and how they can be assessed with cognitive neuroscience methods, mainly focusing on neuroimaging. We discuss how multivariate analysis techniques such as representational similarity analysis (RSA) and deep neural networks (DNNs) can be leveraged to gain insights into the structure of neural representations and their different representational formats. We provide several examples of recent studies which demonstrate that we are able to not only measure memory representations using RSA but are also able to investigate their multiple formats using DNNs. We demonstrate that in addition to slow generalization during consolidation, memory representations are subject to semantization already during short-term memory, by revealing a shift from visual to semantic format. In addition to perceptual and conceptual formats, we describe the impact of affective evaluations as an additional dimension of episodic memories. Overall, these studies illustrate how the analysis of neural representations may help us gain a deeper understanding of the nature of human memory.

Hydrocortisone Differentially Affects Reinstatement of Pain-related Responses in Patients With Chronic Back Pain and Healthy Volunteers

Despite the crucial role of effective and sustained extinction of conditioned pain-related fear in cognitive-behavioral treatment approaches for chronic pain, experimental research on extinction memory retrieval in chronic pain remains scarce. In healthy populations, extinction efficacy of fear memory is affected by stress. Therefore, we investigated the effects of oral hydrocortisone administration on the reinstatement of pain-related associations in 57 patients with non-specific chronic back pain (CBP) and 59 healthy control (HC) participants in a differential pain-related conditioning paradigm within a placebo-controlled, randomized, and double-blind design. Participants' skin conductance responses indicate hydrocortisone-induced reinstatement effects in HCs but no observable reinstatement in HCs receiving placebo treatment. Interestingly, these effects were reversed in patients with CBP, that is, reinstatement responses were only observed in the placebo and not in the hydrocortisone group. Our findings corroborate previous evidence of stress-induced effects on extinction efficacy and reinstatement of fear memory in HCs, extending them into the pain context, and call for more research to clarify the role of stress in fear extinction and return of fear phenomena possibly contributing to treatment failure in chronic pain treatment. PERSPECTIVE: Opposing effects in HCs and patients with non-specific CBP may be associated with changes in the patients' stress systems. These findings could be of relevance to optimizing psychological, extinction-based treatment approaches.

How emotional contexts modulate item memory in individuals with high and low negative affect and worry

Emotional stimuli are usually remembered with high confidence. Yet, it remains unknown whether-in addition to memory for the emotional stimulus itself-memory for a neutral stimulus encountered just after an emotional one can be enhanced. Further, little is known about the interplay between emotion elicited by a stimulus and emotion relating to affective dispositions. To address these questions, we examined (1) how emotional valence and arousal of a context image preceding a neutral item image affect memory of the item, and (2) how such memory modulation is affected by two hallmark features of emotional disorders: trait negative affect and tendency to worry. In two experiments, participants encoded a series of trials in which an emotional (negative, neutral, or positive) context image was followed by a neutral item image. In experiment 1 (n = 42), items presented seconds after negative context images were remembered better and with greater confidence compared to those presented after neutral and positive ones. Arousal ratings of negative context images were higher compared to neutral and positive ones and the likelihood of correctly recognizing an item image was related to higher arousal of the context image. In experiment 2 (n = 59), better item memory was related to lower trait negative affect. Participants with lower trait negative affect or tendency to worry displayed higher confidence compared to those with high negative affect or tendency to worry. Our findings describe an emotional "carry-over" effect elicited by a context image that enhances subsequent item memory on a trial-by-trial basis, however, not in individuals with high trait negative affect who seem to have a general memory disadvantage.

The impact of COVID-19 restrictions on sexual assault in Western Denmark

This study sets out to investigate whether the 15-month nationwide COVID-19 lockdown in Denmark had an impact on the victim demographics, location of sexual assaults, and relationship between victim and perpetrator in the Western part of Denmark compared to the 15 months prior to the lockdown initiatives. This study is a retrospective study including a total of 596 cases. Cases were identified in the database of the Department of Forensic Medicine Aarhus, including cases labeled "rape," "attempted rape," and "later reported." 315 cases were found between March 11th 2020 and June 10th 2021 (lockdown) and 281 cases were found between December 11th 2018 and March 10th 2020(pre-lockdown). Fewer victims were in the age group 15-24 during lockdown (58.4%) than pre-lockdown (71.7%). Fewer stranger rapes occurred during lockdown (11%) than pre-lockdown (19.7%). During lockdown, more sexual assault occurred at a private site (80.1%) than pre-lockdown (60%); correspondingly, fewer public sexual assaults occurred during lockdown (10.3%) than pre-lockdown (26%). No statistically significant difference was observed regarding police reporting of the assault or alcohol intake in the victim prior to assault. We found an overall change in demographics regarding sexual assaults during the lockdown period indicating the restrictions during the lockdown could have affected the patterns of sexual assault in Denmark.

The interplay between memory control and emotion regulation

Memory control (MC) and emotion regulation (ER) are critical cognitive functions for adapting to life's challenges, drawing significant research attention. Accumulating evidence suggests these processes are interrelated, yet a comprehensive discussion of their interplay remains lacking. We introduce an integrative framework exploring the mutual influence between MC and ER, composed of two interrelated branches: first, MC aids in ER through the retrieval of positive memories, intentional forgetting of undesirable content, and the adaptive updating of memory stores. Second, ER impacts MC by upregulating positivity and downregulating negativity in memories. The framework spotlights the need to harness MC-ER interplay for future research. Potential directions include utilizing MC to amplify ER capabilities, training ER skills to refine MC performance, and modulating the cognitive and neural overlapping of both processes to improve both functions. Delving into the MC-ER nexus advances understanding of the intricate emotion-memory relationship and holds great promise for developing novel behavioral interventions.

Social evaluative stress enhances central detail memory, reduces false memory, and results in intrusive memories that last for days

Few studies have quantified what an individual remembers about a laboratory-controlled stressor. Here, we aimed to replicate previous work by using a modified version of the Trier Social Stress Test (TSST) to quantify participant memory for a stressful experience. We also aimed to extend this work by quantifying false and intrusive memories that ensued. One hundred and seven participants were exposed to the TSST (stress) or the friendly TSST (f-TSST; no stress). The TSST required participants to deliver a ten-minute speech in front of two laboratory panel members as part of a mock job interview; the f-TSST required participants to casually converse with the panel members about their interests. In both conditions, the panel members interacted with (central) or did not interact with (peripheral) several objects sitting on a desk in front of them. The next day, participants' memory for the objects was assessed with recall and recognition tests. We also quantified participants' intrusive memories on Days 2, 4, 6, and 8. Stressed participants recalled more central objects and exhibited greater recognition memory, particularly for central objects, than controls. Stress also led to less false recall and more intrusive memories on Days 2 and 4. Consistent with previous work, these findings suggest that participants exhibit enhanced memory for the central details of a stressful experience; they also extend prior work by showing that participants exposed to a stressor have less false memories and experience intrusive memories for several days following the event. The modified TSST paradigm used here may be useful for researchers studying not only what participants remember about a stressful event but also their susceptibility to intrusive memory formation.

Acute Stress Enhances Memory and Preference for Smoking-Related Associations in Smokers

INTRODUCTION

Nicotine dependence follows a chronic course that is characterized by repeated relapse, often driven by acute stress and rewarding memories of smoking retrieved from related contexts. These two triggers can also interact, with stress influencing retrieval of contextual memories. However, the roles of these processes in nicotine dependence remain unknown.

AIMS AND METHODS

We investigated how acute stress biases memory for smoking-associated contexts among smokers (N = 65) using a novel laboratory paradigm. On day 1, participants formed associations between visual stimuli of items (either neutral or related to smoking) and places (background scenes). On day 2 (24 hours later), participants were exposed to an acute laboratory-based stressor (socially evaluated cold pressor test; N = 32) or a matched control condition (N = 33) prior to being tested on their memory recognition and preferences for each item and place. We distinguished the accuracy of memory into specific (ie, precisely correct) or gist (ie, lure items with similar content) categories.

RESULTS

Results demonstrated that the stressor significantly induced physiological and subjective perceived stress responses, and that stressed smokers exhibited a memory bias in favor of smoking-related items. In addition, the stressed group displayed greater preference for both smoking-related items and places that had been paired with the smoking-related items. We also found suggestive evidence that stronger smoking-related memory biases were associated with more severe nicotine dependence (ie, years of smoking).

CONCLUSIONS

These results highlight the role of stress in biasing smokers toward remembering contexts associated with smoking, and amplifying their preference for these contexts.

IMPLICATIONS

The current study elucidates the role of acute stress in promoting memory biases favoring smoking-related associations among smokers. The results suggest that the retrieval of smoking-biased associative memory could be a crucial factor in stress-related nicotine seeking. This may lead to a potential intervention targeting the extinction of smoking-related context memories as a preventive strategy for stress-induced relapse.

Acute stress negatively impacts on-task behavior and lecture comprehension

Acute stress has been shown to disrupt cognitive and learning processes. The present study examined the effects of acute stress on mind wandering during a lecture and subsequent lecture comprehension in young adults. Forty participants were randomized to acute stress induction via the Trier Social Stress Test or rest prior to watching a twenty-minute video lecture with embedded mind wandering probes, followed by a lecture comprehension assessment. Stress responses were assessed via heart rate, blood pressure, salivary cortisol, and state anxiety. Individuals exposed to acute stress endorsed greater mind wandering at the first checkpoint and lower lecture comprehension scores. Moreover, state anxiety post stress was positively associated with mind wandering at the first and second checkpoint and negatively associated with lecture comprehension. Only mind wandering at the third checkpoint was negatively correlated with overall lecture comprehension. Taken together, these data suggest that acute stress, mind wandering, and lecture comprehension are inextricably linked.

Writing about a stressful experience improves semantic clustering of memory in men, not women

Writing about negative experiences can produce multiple benefits, including improvements in mental and emotional health. However, writing about negative experiences potentially be detrimental, as reliving and reexperiencing a negative memory can be painful. Although the emotional effects of writing about negative experiences are well established, the cognitive effects are less heavily explored, and no work to date has examined how writing about a stressful experience might influence episodic memory. We addressed this issue in the present study (N = 520) by having participants encode a list of 16 words that were organised around four semantic clusters, randomly assigning participants to write about an unresolved stressful experience (n = 263) or the events of the previous day (n = 257), and assessing their memory in a free recall task. Writing about a stressful experience did not influence overall memory performance; however, the stressful writing manipulation increased semantic clustering of information within memory for men, whereas the stressful writing manipulation did not influence semantic clustering of information within memory in women. Additionally, writing with more positive sentiment improved semantic clustering and reduced serial recall. These results provide evidence for unique sex differences in writing about stressful experiences and the role of sentiment in the effects of expressive writing.

Incidence and risk factors of venous thromboembolism in kidney transplantation patients: a prospective cohort study

To investigate the incidence and explore the risk factors of venous thromboembolism (VTE) within 6 months after kidney transplantation. Total of 331 kidney transplant recipients were assessed by venous ultrasonography for VTE at 14 days, 1 month, 3 months, and 6 months post-transplantation. Cox forward regression were used to identify the independent risk factors of VTE. This study registration number is ChiCTR1900020567 and the date of registration was 2019/01/08. The cumulative incidence of VTE was 2.72% (9/331) within 6 months after transplant. 77.8% (7/9) of VTEs occurred in the first 3 months post-transplantation. 88.9% (1/9) of VTEs were asymptomatic, 66.7% (6/9) of VTEs were mural thromboses and in the right lower extremity. Central vena catheterization (HR = 6.94) and severe pulmonary disease (including pneumonia) (HR = 57.35) were the risk factors for VTE in kidney transplantation recipients. KT patients are the high risk population of VTE. Future interventions should be strengthen for KT patients to receive a minimum of 3-month of precautionary measures for VTE, including infection prevention, and strengthening thromboprophylaxis on the CVC or transplanted side of lower extremity.

The effect of negative emotion processing on spatial navigation: an experimental study using virtual reality

Finding one's way in unfamiliar environments is an essential ability. When navigating, people are overwhelmed with an enormous amount of information. However, some information might be more relevant than others. Despite the mounting knowledge about the mechanisms underlying orientational skills, and the notable effects of facial emotions on human behavior, little is known about emotions' effects on spatial navigation. Hereby, this study aimed to explore how exposure to others' negative emotional facial expressions affects wayfinding performances. Moreover, gender differences that characterize both processes were considered. Fifty-five participants (31 females) entered twice in three realistic virtual reality environments: the first time, to encode a route to find an object and then to recall the learned path to reach the same object again. In between the two explorations of the virtual environment, participants were asked to undergo a gender categorization task during which they were exposed to sixty faces showing either neutral, fearful, or angry expressions. Results showed a significant interaction between emotions, time, and gender. In particular, the exposition to fearful faces, but not angry and neutral ones, decreased males' wayfinding performances (i.e., travel times and distance travelled), while females' performances were unaffected. Possible explanations for such gender and emotional dissimilarities are discussed.

The Hypothalamus-Pituitary-Adrenal Axis and Social Cognition in Borderline Personality Disorder

Borderline personality disorder (BPD) is characterized by emotional instability, impulsivity and unstable interpersonal relationships. Patients experience discomforting levels of distress, inducing symptoms like dissociation, aggression or withdrawal. Social situations are particularly challenging, and acute social stress can reduce patients' cognitive and social functioning. In patients with Major Depressive Disorder or Posttraumatic Stress Disorder, which show high comorbidity with BPD, the endocrine stress response is characterized by Hypothalamus-Pituitary-Adrenal (HPA) axis dysfunction, which affects cognitive functioning. Compared to these clinical groups, research on HPA-axis function in BPD is relatively scarce, but evidence points towards a blunted cortisol reactivity to acute stress. Since BPD patients are particularly prone to social stress and experience high subjective difficulties in these situations, it seems plausible that HPA-axis dysregulation might contribute to decreased social cognition in BPD. The present review summarizes findings on the HPA-axis function in BPD and its association with social cognition following acute social stress. For this purpose, we review literature that employed a widely used social stressor (Trier Social Stress Test, TSST) to study the effects of acute social stress on social cognition and the HPA-axis response. We contrast these findings with studies on social cognition that employed Cyberball, another widely used social stressor that lacks HPA-axis involvement. We conclude that research on social cognition in BPD reveals heterogeneous results with no clear relationship between social functioning and HPA-axis response. More research is needed to better understand the psychophysiological underpinnings of impaired social cognition in BPD.

Metabolomics reveals that chronic restraint stress alleviates carbon tetrachloride-induced hepatic fibrosis through the INSR/PI3K/AKT/AMPK pathway

Hepatic fibrosis (HF) could be developed into liver cirrhosis or even hepatocellular carcinoma. Stress has an important role in the occurrence and development of various considerable diseases. However, the effect of a certain degree stress on HF is still controversial. In our study, stress was simulated with regular chronic restraint stress (CRS) and HF model was induced with CCl4 in mice. We found that CRS was able to attenuate CCl4-induced liver injury and fibrosis in mice. Surprisingly, behavioral analysis showed that the mice in the HF group exhibited depression-like behavior. Further, the metabolomic analysis revealed that 119 metabolites and 20 metabolic pathways were altered in mice liver, especially the betaine metabolism pathway. Combined with the results of Ingenuity Pathway Analysis (IPA), the key proteins INSR, PI3K, AKT, and p-AMPK were identified and verified, and the results showed that CRS could upregulate the protein levels and mRNA expression of INSR, PI3K, AKT, and p-AMPK in liver tissues of HF mice. It suggested that CRS alleviated CCl4-induced liver fibrosis in mice through upregulation of the INSR/PI3K/AKT/AMPK pathway. Proper stress might be a potential therapeutic strategy for the treatment of chronic liver disease, which provided new insights into the treatment of HF. KEY MESSAGES: Chronic restraint stress mitigated CCl4-induced liver injury and hepatic fibrosis. CCl4-induced liver fibrosis could cause depression-like behavior. Chronic restraint stress altered metabolomic profiles in hepatic fibrosis mice, especially the betaine metabolism pathway. Chronic restraint stress increased betaine levels in liver tissue. Chronic restraint stress regulated the INSR/PI3K/AKT/AMPK signaling pathway in hepatic fibrosis mice.

Neuromonitoring Changes in Spinal Deformity Surgery

Spinal cord injury is one of the most feared complications in spinal deformity surgery. The surgeon must be vigilant of direct and indirect sources of injury at all points during surgery. The incidence of complications has greatly decreased with the ability to monitor the motor and sensory pathways. Changes in signaling of these pathways provide context for what the insult is, and how to correct it before it becomes irreversible. There are well-established protocols that provide an algorithmic response to changes that can help all in the room determine the source of injury, and the appropriate reaction.

Stress-related cellular pathophysiology as a crosstalk risk factor for neurocognitive and psychiatric disorders

In this narrative review, we examine biological processes linking psychological stress and cognition, with a focus on how psychological stress can activate multiple neurobiological mechanisms that drive cognitive decline and behavioral change. First, we describe the general neurobiology of the stress response to define neurocognitive stress reactivity. Second, we review aspects of epigenetic regulation, synaptic transmission, sex hormones, photoperiodic plasticity, and psychoneuroimmunological processes that can contribute to cognitive decline and neuropsychiatric conditions. Third, we explain mechanistic processes linking the stress response and neuropathology. Fourth, we discuss molecular nuances such as an interplay between kinases and proteins, as well as differential role of sex hormones, that can increase vulnerability to cognitive and emotional dysregulation following stress. Finally, we explicate several testable hypotheses for stress, neurocognitive, and neuropsychiatric research. Together, this work highlights how stress processes alter neurophysiology on multiple levels to increase individuals' risk for neurocognitive and psychiatric disorders, and points toward novel therapeutic targets for mitigating these effects. The resulting models can thus advance dementia and mental health research, and translational neuroscience, with an eye toward clinical application in cognitive and behavioral neurology, and psychiatry.

Threat impairs flexible use of a cognitive map

Goal-directed behavior requires adaptive systems that respond to environmental demands. In the absence of threat (or presence of reward), individuals can explore many behavioral trajectories, effectively interrogating the environment across multiple dimensions. This leads to flexible, relational memory encoding and retrieval. In the presence of danger, motivation shifts to an imperative state characterized by a narrow focus of attention on threatening information. This impairs flexible, relational memory. We test how these motivational shifts (Murty & Adcock, 2017) affect behavioral flexibility in an ecologically valid setting. Participants learned the structure of maze-like environments and navigated to the location of objects in both safe and threatening contexts. The latter contained a predator that could 'capture' participants, leading to electric shock. After learning, the path to some objects was unpredictably blocked. forcing a detour for which one route was significantly shorter. We predicted that threat would push participants toward an imperative state, leading to less efficient and less flexible navigation. Threat caused participants to take longer paths to goal objects and less efficient detours when obstacles were encountered. Threat-related impairments in detour navigation persisted after controlling for non-detour navigation performance. and non-detour navigation was not a reliable predictor of detour navigation, This suggests a specific impairment in flexible navigation during detours, an impairment unlikely to be explained by more general processes like predator avoidance or divided attention that may be present during non-detour navigation. These results provide ecologically valid evidence that dynamic, observable threats reduce flexible use of cognitive maps to guide behavior.

The effects of early-life and intergenerational stress on the brain

Stress experienced during ontogeny can have profound effects on the adult phenotype. However, stress can also be experienced intergenerationally, where an offspring's phenotype can be moulded by stress experienced by the parents. Although early-life and intergenerational stress can alter anatomy, physiology, and behaviour, nothing is known about how these stress contexts interact to affect the neural phenotype. Here, we examined how early-life and intergenerational stress affect the brain in eastern fence lizards (Sceloporus undulatus). Some lizard populations co-occur with predatory fire ants, and stress from fire ant attacks exerts intergenerational physiological and behavioural changes in lizards. However, it is unclear if intergenerational stress, or the interaction between intergenerational and early-life stress, modulates the brain. To test this, we captured gravid females from fire ant invaded and uninvaded populations, and subjected offspring to three early-life stress treatments: (1) fire ant attack, (2) corticosterone, or (3) a control. Corticosterone and fire ant attack decreased some aspects of the neural phenotype while population of origin and the interaction of early-life stress and population had no effects on the brain. These results suggest that early-life stressors may better predict adult brain variation than intergenerational stress in this species.

Back to the future: Progressing memory research in eating disorders

OBJECTIVE

Human behaviors, thoughts, and emotions are guided by memories of the past. Thus, there can be little doubt that memory plays a fundamental role in the behaviors (e.g., binging), thoughts (e.g., body-image concerns), and emotions (e.g., guilt) that characterize eating disorders (EDs). Although a growing body of research has begun to investigate the role of memory in EDs, this literature is limited in numerous ways and has yet to be integrated into an overarching framework.

METHODS

In the present article, we provide an operational framework for characterizing different domains of memory, briefly review existing ED memory research within this framework, and highlight crucial gaps in the literature.

RESULTS

We distinguish between three domains of memory-episodic, procedural, and working-which differ based on functional attributes and underlying neural systems. Most recent ED memory research has focused on procedural memory broadly defined (e.g., reinforcement learning), and findings within all three memory domains are highly mixed. Further, few studies have attempted to assess these different domains simultaneously, though most behavior is achieved through coordination and competition between memory systems. We, therefore, offer recommendations for how to move ED research forward within each domain of memory and how to study the interactions between memory systems, using illustrative examples from other areas of basic and clinical research.

DISCUSSION

A stronger and more integrated understanding of the mechanisms that connect memory of past experiences to present ED behavior may yield more comprehensive theoretical models of EDs that guide novel treatment approaches.

PUBLIC SIGNIFICANCE

Memories of previous eating-related experiences may contribute to the onset and maintenance of eating disorders (EDs). However, research on the role of memory in EDs is limited, and distinct domains of ED memory research are rarely connected. We, therefore, offer a framework for organizing, progressing, and integrating ED memory research, to provide a better foundation for improving ED treatment and intervention going forward.