Stress potentiates decision biases: A stress induced deliberation-to-intuition (SIDI) model

Investigating the temporal dynamics of electroencephalogram (EEG) microstates using recurrent neural networks

Electroencephalogram (EEG) microstates that represent quasi‐stable, global neuronal activity are considered as the building blocks of brain dynamics. Therefore, the analysis of microstate sequences is a promising approach to understand fast brain dynamics that underlie various mental processes. Recent studies suggest that EEG microstate sequences are non‐Markovian and nonstationary, highlighting the importance of the sequential flow of information between different brain states. These findings inspired us to model these sequences using Recurrent Neural Networks (RNNs) consisting of long‐short‐term‐memory (LSTM) units to capture the complex temporal dependencies. Using an LSTM‐based auto encoder framework and different encoding schemes, we modeled the microstate sequences at multiple time scales (200–2,000 ms) aiming to capture stably recurring microstate patterns within and across subjects. We show that RNNs can learn underlying microstate patterns with high accuracy and that the microstate trajectories are subject invariant at shorter time scales (≤400 ms) and reproducible across sessions. Significant drop in the reconstruction accuracy was observed for longer sequence lengths of 2,000 ms. These findings indirectly corroborate earlier studies which indicated that EEG microstate sequences exhibit long‐range dependencies with finite memory content. Furthermore, we find that the latent representations learned by the RNNs are sensitive to external stimulation such as stress while the conventional univariate microstate measures (e.g., occurrence, mean duration, etc.) fail to capture such changes in brain dynamics. While RNNs cannot be configured to identify the specific discriminating patterns, they have the potential for learning the underlying temporal dynamics and are sensitive to sequence aberrations characterized by changes in metal processes. Empowered with the macroscopic understanding of the temporal dynamics that extends beyond short‐term interactions, RNNs offer a reliable alternative for exploring system level brain dynamics using EEG microstate sequences.

Neural correlates of enhanced response inhibition in the aftermath of stress

Life stress has been shown to impact cognitive functions, including inhibitory control. However, the immediate effects of acute stress on inhibitory control and the underlying neural mechanisms remain unclear. In a behavioral pilot study (N = 30) and a within-subject functional magnetic resonance imaging study (N = 30), we examined how acute stress induced by Trier Social Stress Test influenced inhibitory control in a stop signal task. Behavioral results across two studies showed that stress consistently improved inhibitory control. Shorter stop signal reaction time (SSRT) in stress as compared with control condition was associated with stronger connectivity between the superior/middle frontal gyrus (SFG/MFG) and striatum. Dynamic causal modeling revealed distinct best models under stress and control condition, with an enhanced interaction between the SFG/MFG and the striatum after stress exposure. This research identified the SFG/MFG-striatum network as a key circuit underlying acute stress-elicited enhancement of inhibitory control in a stop signal task.

Speech-Language Pathologists' Perceptions of Nonnative Accent: A Pilot Study

Purpose

Considering the American Speech-Language-Hearing Association's (ASHA) global influence and continued emphasis on heightening multicultural receptivity, a major consideration for ASHA is to cultivate cultural sensitivity and competence in its largely female (95.30%), monolingual (93.46%), and White (92.10%) workforce. ASHA's 32-year transition from no formal multicultural education to mandatory multicultural education infusion provokes to enquire whether multicultural education in speech-language pathologists (SLPs) has modified SLPs' perceptions toward multicultural issues. In this article, we explored an aspect of such sensitivity. We want to know whether there exists a linear relationship between SLPs' age, as an index of their exposure to formal multicultural education, and SLPs' bias toward nonnative accent, as an index of their multicultural sensitivity.

Method

Two hundred sixty-eight SLP ASHA members completed a web-based pilot survey testing whether SLPs made biased associations based on personality traits, sociocultural factors, professional attire, and physical appearance of persons with nonnative accent and whether the SLPs thought they had an accent. Logistic regression tested whether age predicts explicit biased associations for these five outcomes.

Results

ASHA SLPs made biased associations with accent for all outcomes, but age only predicted the likelihood of explicit accent-based biases for physical appearance. The relationship was curvilinear, with 40- to 45-year-olds making the most biased associations and older SLPs making progressively fewer biased associations.

Conclusion

Clearly, the specific psychosocial attributes associated with perception of nonnative accent need to be explored from a dynamical systems perspective to discover potential variables that might directly or indirectly influence accent perception and potential biases.

Acute social stress modulates coherence regional homogeneity

It is a generally accepted observation that individuals act differently under stress. Recent task-based neuroimaging studies have shown that individuals under stress favor the intuitive and fast system over the deliberative and reflective system. In the present study, using a within-subjects design in thirty young adults, we examined whether and how acute social stress impacts regional neural activity in resting state. The results showed that stress induced lower coherence regional homogeneity (Cohe-ReHo) values in left hippocampus and right superior frontal gyrus, both of which are regions associated with deliberative decision making. Stress-induced cortisol change was significantly and positively correlated with the change in Cohe-ReHo value in the right midbrain, a region involved in habitual decision making. These results extend previous findings by demonstrating that stress modulates local synchrony in brain regions implicated in deliberative and intuitive decision making. Our findings might be useful in understanding the neural mechanisms underlying stress-related mental disorders.

Hippocampal connectivity in the aftermath of acute social stress

The hippocampus is a core brain region that responds to stress. Previous studies have found a dysconnectivity between hippocampus and other brain regions under acute and chronic stress. However, whether and how acute social stress influences the directed connectivity patterns from and to the hippocampus remains unclear. In this study, using a within-subject design and Granger causal analysis (GCA), we investigated the alterations of resting state effective connectivity from and to hippocampal subregions after an acute social stressor (the Trier Social Stress Test). Participants were engaged in stress and control conditions spaced approximately one month apart. Our findings showed that stress altered the information flows in the thalamus-hippocampus-insula/midbrain circuit. The changes in this circuit could also predict with high accuracy the stress and control conditions at the subject level. These hippocampus-related brain networks have been documented to be involved in emotional information processing and storage, as well as habitual responses. We speculate that alterations of the effective connectivity between these brain regions may be associated with the registering and encoding of threatening stimuli under stress. Our investigation of hippocampal functional connectivity at a subregional level may help elucidate the functional neurobiology of stress-related psychiatric disorders.

Multilevel Impacts of Iron in the Brain: The Cross Talk between Neurophysiological Mechanisms, Cognition, and Social Behavior

Iron is a critical element for most organisms, which plays a fundamental role in the great majority of physiological processes. So much so, that disruption of iron homeostasis has severe multi-organ impacts with the brain being particularly sensitive to such modifications. More specifically, disruption of iron homeostasis in the brain can affect neurophysiological mechanisms, cognition, and social behavior, which eventually contributes to the development of a diverse set of neuro-pathologies. This article starts by exploring the mechanisms of iron action in the brain and follows with a discussion on cognitive and behavioral implications of iron deficiency and overload and how these are framed by the social context. Subsequently, we scrutinize the implications of the disruption of iron homeostasis for the onset and progression of psychosocial disorders. Lastly, we discuss the links between biological, psychological, and social dimensions and outline potential avenues of research. The study of these interactions could ultimately contribute to a broader understanding of how individuals think and act under physiological and pathophysiological conditions.

Reduced Hedonic Valuation of Rewards and Unaffected Cognitive Regulation in Chronic Stress

Cognition can influence choices by modulation of decision-making processes. This cognitive regulation is defined as processing information, applying knowledge, and changing preferences to consciously modulate decisions. While cognitive regulation of emotions has been extensively studied in psychiatry, few works have detailed cognitive regulation of decision-making. Stress may influence emotional behavior, cognition, and decision-making. In addition, the brain regions responsible for decision-making are sensitive to stress-induced changes. Thus, we hypothesize that chronic stress may disrupt the ability to regulate choices. Herein, we used a functional magnetic resonance imaging task where fourteen control and fifteen chronically stressed students had to cognitively upregulate or downregulate their craving before placing a bid to obtain food. We found that stressed participants placed lower bids to get the reward and chose less frequently higher bid values for food. Nevertheless, we did not find neural and behavioral differences during cognitive regulation of craving. Our outcomes revealed that chronic stress impacts decision-making after cognitive regulation of craving by reducing the valuation of food rewards but not cognitive modulation itself. Importantly, our results need further validation with larger sample sizes.

Associations Between Natural Physiological and Supraphysiological Estradiol Levels and Stress Perception

Stress is a risk factor for impaired general, mental, and reproductive health. The role of physiological and supraphysiological estradiol concentrations in stress perception and stress processing is less well understood. We, therefore, conducted a prospective observational study to investigate the association between estradiol, stress perception, and stress-related cognitive performance within serial measurements either during the natural menstrual cycle or during fertility treatment, where estradiol levels are strongly above the physiological level of a natural cycle, and consequently, represent a good model to study dose-dependent effects of estradiol. Data from 44 women receiving in vitro fertilization (IVF) at the Department of Reproductive Endocrinology in Zurich, Switzerland was compared to data from 88 women with measurements during their natural menstrual cycle. The German version of the Perceived Stress Questionnaire (PSQ) and the Cognitive Bias Test (CBT), in which cognitive performance is tested under time stress were used to evaluate subjective and functional aspects of stress. Estradiol levels were investigated at four different time points during the menstrual cycle and at two different time points during a fertility treatment. Cycle phases were associated with PSQ worry and cognitive bias in normally cycling women, but different phases of fertility treatment were not associated with subjectively perceived stress and stress-related cognitive bias. PSQ lack of joy and PSQ demands related to CBT in women receiving fertility treatment but not in women with a normal menstrual cycle. Only strong changes of the estradiol level during fertility treatment were weakly associated with CBT, but not with subjectively experienced stress. Our research emphasizes the multidimensional character of stress and the necessity to adjust stress research to the complex nature of stress perception and processing. Infertility is associated with an increased psychological burden in patients. However, not all phases of the process to overcome infertility do significantly increase patient stress levels. Also, research on the psychological burden of infertility should consider that stress may vary during the different phases of fertility treatment. Clinical trial registration: ClinicalTrials.gov # NCT02098668.

To trust, or not to trust? Individual differences in physiological reactivity predict trust under acute stress

The stress response represents an evolutionarily ancient array of biological responses to challenge or threat that facilitate survival by promoting adaptive behaviors. 'Adaptive' in the evolutionary sense, however, does not easily translate to explain stress' effect on human decisions. Much research demonstrates that acute stress alters decision-making, but outcomes are obscured by a range of methodological factors. Further, less is known about how stress affects decision-making in social contexts in which people so often act. This is of great importance in today's increasingly complex social environment, replete with potential stressors, where cooperation and trust are critical. Here the aim was to explore acute stress' effect on prosocial decision-making, while also controlling for methodological factors that may contribute to varied research outcomes. Ninety-six participants were exposed between-subjects to acute stressors with or without a significant social evaluative component, or a control procedure, after which they performed a variant of the Trust Game (a social decision-making task requiring cooperation and trust with a 'partner'). Task performance occurred at different times with respect to exposure to examine the roles of temporally distinct biological stress pathways. Overall acute stress was associated with reduced trust, but a more complex pattern emerged when accounting for individual differences in physiological stress responses via multivariate analysis. In keeping with the complexity of stress itself, acute stress may enhance or reduce propensity to trust based on an individual's unique pattern of physiological reactivity.

Contemplative neuroscience, self-awareness, and education

Accumulating research in education shows that contemplative practices contribute to and foster well-being of individuals in sustainable ways. This bears special importance for teachers, as it affects not only them but also their students. Based on accumulating behavioral and neuroscientific findings, it has been suggested that a key process by which mindfulness meditation enhances self-regulation is the altering of self-awareness. Indeed, accumulated work shows that the underlying networks supporting various types of self-awareness are malleable following meditative practice. However, the field of education has developed independently from the study of the self and its relation to contemplative neuroscience thus far, and to date there is no systematic account linking this accumulating body of knowledge to the field of education or discussing how it might be relevant to teachers. Here we show how incorporating insights from contemplative neuroscience-which are built on the conceptualization and neuroscience of the self-into contemplative pedagogy can inform the field and might even serve as a core underlying mechanism tying together different empirical evidence. This review points to potential neural mechanisms by which mindfulness meditation helps teachers manage stress and promote supportive learning environments, resulting in improved educational outcomes, and thus it has significant implications for educational policy regarding teachers.

Effects of acute stress on social behavior in women

Acute stress is known to increase prosocial behavior in men via a "tend-and-befriend" pattern originally proposed as a specifically female stress response alongside the fight-or-flight response. However, the direct effects of acute stress on women's social behavior have not been investigated. Applying the Trier Social Stress Test for groups (TSST-G), 94 women were confronted with either a stress or control condition. We repeatedly measured their subjective stress responses, salivary cortisol, and heart rate, and investigated their level of trust, trustworthiness, sharing, punishment and non-social risk using social decision paradigms. We detected significant increases in all stress parameters, as well as the wish for closeness during the stress condition. Acute stress exposure elevated prosocial trustworthiness and sharing without affecting non-social risk behavior. These results are in line with findings on the effects of stress in men, and further validate the tend-and-befriend pattern as one possible behavioral response during stress in humans.

Chronic Stress and Moral Decision-Making: An Exploration With the CNI Model

Stress is prevalent in our daily life, and people often make moral decision-making in a stressful state. Several studies indicated the influence of acute stress on moral decision-making and behavior. The present study extended the investigation to chronic stress, and employed a new approach, the CNI model, to add new insights regarding the mechanism underlying the association between chronic stress and moral decision-making. A total of 197 undergraduates completed the Perceived Stress Scale and made moral decision-making on a series of deliberately designed moral dilemmas. The results indicated that higher chronic stress was related to more deontological moral choices. The process-dissociation analyses revealed that chronic stress was marginally significantly associated with deontological inclinations but not with utilitarian inclinations. And the CNI model analyses suggested that the high-stress group (above the median) showed a stronger general preference for inaction than the low-stress group (below the median) did, but there were no significant differences in sensitivity to consequences or sensitivity to moral norms between the two groups. Finally, the implications of the findings were discussed.

Updating Beliefs under Perceived Threat

Humans are better at integrating desirable information into their beliefs than undesirable information. This asymmetry poses an evolutionary puzzle, as it can lead to an underestimation of risk and thus failure to take precautionary action. Here, we suggest a mechanism that can speak to this conundrum. In particular, we show that the bias vanishes in response to perceived threat in the environment. We report that an improvement in participants' tendency to incorporate bad news into their beliefs is associated with physiological arousal in response to threat indexed by galvanic skin response and self-reported anxiety. This pattern of results was observed in a controlled laboratory setting (Experiment I), where perceived threat was manipulated, and in firefighters on duty (Experiment II), where it naturally varied. Such flexibility in how individuals integrate information may enhance the likelihood of responding to warnings with caution in environments rife with threat, while maintaining a positivity bias otherwise, a strategy that can increase well-being.SIGNIFICANCE STATEMENT The human tendency to be overly optimistic has mystified scholars and lay people for decades: How could biased beliefs have been selected over unbiased beliefs? Scholars have suggested that although the optimism bias can lead to negative outcomes, including financial collapse and war, it can also facilitate health and productivity. Here, we demonstrate that a mechanism generating the optimism bias, namely asymmetric information integration, evaporates under threat. Such flexibility could result in enhanced caution in dangerous environments while supporting an optimism bias otherwise, potentially increasing well-being.

The Beneficial or Harmful Effects of Computer Game Stress on Cognitive Functions of Players

Introduction:

Video games are common cultural issues with great influence in all societies. One of the important cognitive effects of video games is on creating stress on video players. The present research objective was to study different types of stress in players based on video game styles.

Methods:

A total of 80 players, aged 18 to 30 years, played four types of video games; Runner game, Excitement game, Fear game, and Puzzle game. In the beginning, the players filled in the form of personal information as well as some general and specialized information on the games. Before starting each game, the saliva samples of the players were collected to measure their level of cortisol and α-amylase. At the end of each game, the same samples were collected again. The concentrations of cortisol and α-amylase were measured using a specialized kit and an ELISA device. In addition, the variations of brain waves were recorded by an Emotiv system. Finally, the data were analyzed in SPSS and Matlab system (after and before playing video game).

Results:

The research findings revealed that the salivary α-amylase concentration increased significantly after playing the Fear game, Runner game, and Excitement game and decreased significantly after playing the Puzzle game. Moreover, the concentration of salivary cortisol increased significantly after playing the Runner game, Excitement game, and Fear game and decreased significantly after playing the Puzzle game. The brain wave analysis also revealed that the level of stress experienced by playing Fear game was higher than the Excitement game.

Conclusion:

According to the research findings, video games can affect the stress system as well as the cognitive system of humans depending on the game style. In addition, the type and level of stress triggered in the players depend on the game style.

Sample Entropy of the Heart Rate Reflects Properties of the System Organization of Behaviour

Cardiac activity is involved in the processes of organization of goal-directed behaviour. Each behavioural act is aimed at achieving an adaptive outcome and it is subserved by the actualization of functional systems consisting of elements distributed across the brain and the rest of the body. This paper proposes a system-evolutionary view on the activity of the heart and its variability. We have compared the irregularity of the heart rate, as measured by sample entropy (SampEn), in behaviours that are subserved by functional systems formed at different stages of individual development, which implement organism-environment interactions with different degrees of differentiation. The results have shown that SampEn of the heart rate was higher during performing tasks that included later acquired knowledge (foreign language vs. native language; mathematical vocabulary vs. general vocabulary) and decreased in the stress and alcohol conditions, as well as at the beginning of learning. These results are in line with the hypothesis that irregularity of the heart rate reflects the properties of a set of functional systems subserving current behaviour, with higher irregularity corresponding to later acquired and more complex behaviour.

Stress Induces Contextual Blindness in Lotteries and Coordination Games

In this paper, we study how stress affects risk taking in three tasks: individual lotteries, Stag Hunt (coordination) games, and Hawk-Dove (anti-coordination) games. Both control and stressed subjects take more risks in all three tasks when the value of the safe option is decreased and in lotteries when the expected gain is increased. Also, subjects take longer to take decisions when stakes are high, when the safe option is less attractive and in the conceptually more difficult Hawk-Dove game. Stress (weakly) increases reaction times in those cases. Finally, our main result is that the behavior of stressed subjects in lotteries, Stag Hunt and Hawk-Dove are all highly predictive of each other (p-value < 0.001 for all three pairwise correlations). Such strong relationship is not present in our control group. Our results illustrate a "contextual blindness" caused by stress. The mathematical and behavioral tensions of Stag Hunt and Hawk-Dove games are axiomatically different, and we should expect different behavior across these games, and also with respect to the individual task. A possible explanation for the highly significant connection across tasks in the stress condition is that stressed subjects habitually rely on one mechanism to make a decision in all contexts whereas unstressed subjects utilize a more cognitively flexible approach.

A Review of Consequences of Poverty on Economic Decision-Making: A Hypothesized Model of a Cognitive Mechanism

This review focuses on the issue of poverty affecting economic decision-making. By critically evaluating existing studies, the authors propose a structural model detailing the cognitive mechanism involved in how poverty negatively impacts economic decision-making, and explores evidence supporting the basis for the formation of this model. The suggested mechanism consists of a relationship between poverty and four other factors: (1) cognitive load (e.g., experiencing negative affect and stress); (2) executive functions (e.g., attention, working memory, and self-control); (3) intuition/deliberation in decision-making; and (4) economic decision-making (e.g., time-discounting and risk preference), with a final addition of financial literacy as a covariate. This paper focuses on shortfalls in published research, and delves further into the proposed model.

Acute psychosocial stress and everyday moral decision-making in young healthy men: The impact of cortisol

In everyday life, moral decisions must frequently be made under acute stress. Although there is increasing evidence that both stress and cortisol affect moral judgment and behavior as well as decision-making in various domains unrelated to morality, surprisingly few attempts have been made to explore the effects of stress on everyday moral decision-making. Therefore, in the present study, we exposed 50 young healthy men to the Trier Social Stress Test (TSST) or its non-stressful placebo version (PTSST). We investigated the impact of acute stress exposure and stress-related cortisol levels on decision-making, decision certainty, and emotions in 28 everyday moral conflict situations with altruistic versus egoistic response alternatives. Results showed that the TSST-exposed group made more altruistic decisions than the non-stress control group, while groups did not differ in decision certainty and emotion ratings. Moreover, in correlational as well as regression analyses, additionally controlling for confounding variables, we observed significant positive associations between cortisol levels and altruistic decision-making. Further analyses revealed that altruistic decisions came along with significantly higher decision certainty and significantly more positive emotion ratings than egoistic decisions. Notably, our data also raise the idea that the personality trait agreeableness plays an important role in everyday moral decision-making. In sum, our findings provide initial evidence that both acute stress exposure and cortisol levels have prosocial effects on everyday moral decision-making in young healthy men.

How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes

Rationale: Advances in neurocomputational modeling suggest that valuation systems for goal-directed (deliberative) on one side, and habitual (automatic) decision-making on the other side may rely on distinct computational strategies for reinforcement learning, namely model-free vs. model-based learning. As a key theoretical difference, the model-based system strongly demands cognitive functions to plan actions prospectively based on an internal cognitive model of the environment, whereas valuation in the model-free system relies on rather simple learning rules from operant conditioning to retrospectively associate actions with their outcomes and is thus cognitively less demanding. Acute stress reactivity is known to impair model-based but not model-free choice behavior, with higher working memory capacity protecting the model-based system from acute stress. However, it is not clear which impact accumulated real life stress has on model-free and model-based decision systems and how this influence interacts with cognitive abilities. Methods: We used a sequential decision-making task distinguishing relative contributions of both learning strategies to choice behavior, the Social Readjustment Rating Scale questionnaire to assess accumulated real life stress, and the Digit Symbol Substitution Test to test cognitive speed in 95 healthy subjects. Results: Individuals reporting high stress exposure who had low cognitive speed showed reduced model-based but increased model-free behavioral control. In contrast, subjects exposed to accumulated real life stress with high cognitive speed displayed increased model-based performance but reduced model-free control. Conclusion: These findings suggest that accumulated real life stress exposure can enhance reliance on cognitive speed for model-based computations, which may ultimately protect the model-based system from the detrimental influences of accumulated real life stress. The combination of accumulated real life stress exposure and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities.