Temporal discounting and heart rate reactivity to stress

Stress and COVID‐19 related behaviours: The mediating role of delay discounting

We examined stress as a predictor of behaviours related to Coronavirus Disease-2019 (COVID-19) through its effects on delay discounting. Adults (N = 3686) completed an online survey with a behavioural measure of delay discounting and questions regarding stress, physical distancing, and stockpiling of food and supplies. Stress was weakly, but positively, correlated with delay discounting (p < 0.01). Delay discounting was positively correlated with stockpiling (p < 0.01); and discounting was negatively correlated with physical distancing (p < 0.01). Mediation models indicated that discounting was a significant mediator of the relationship between stress and physical distancing (-0.003) and stockpiling (0.003); bootstrap 95% CIs (-0.006, -0.001) and (0.001, 0.005), respectively. After accounting for its indirect effects through discounting, stress continued to have a direct effect on these outcomes. This study indicates that delay discounting partially mediates the link between stress and behaviours related to COVID-19. Results suggest that interventions reducing stress and/or delay discounting may be profitable for increasing infection prevention and reducing stockpiling.

Mental Fatigue and Basketball Performance: A Systematic Review

Mental fatigue (MF) is a psycho-biological state that impairs sports-related performances. Recently, it has been proved that MF can affect basketball performance. However, a systematic overview detailing the influences of MF on basketball performance is still lacking. This study aims to investigate the effects of MF on the physical, technical, tactical, and cognitive performance of basketball. We used the databases of PubMed, Web of Science, SPORTDiscus, Scopes, and CKNI for articles published up to 31 May 2021. The articles included in this study were projected to test whether MF influences basketball athlete performance. Only experimental design studies were selected, and the control condition was without MF. Finally, seven articles fit the inclusion criteria. The results imply that MF impairs the technical aspects of basketball (free throws, three-point shots, and total turnover) and the players' cognitive [take-the-first (TTF) heuristics and decision-making] performance, which results in athletes not using their techniques skillfully and being unable to make practical decisions during critical points in the game. In addition to that, the influences of MF on physical and tactical performance have not been studied. Further studies should look into comprehensive research on the influences of MF on basketball performance, especially on a player's physical and tactical performance.

Systematic Review Registration: [https://inplasy.com/] [INPLASY2021100017].

Now or Later? Stress-Induced Increase and Decrease in Choice Impulsivity Are Both Associated with Elevated Affective and Endocrine Responses

Exposure to acute stress elicit physiological and psychological responses that can impact decision-making, often expressed as an increased tendency to act in an impulsive manner following stress. Delay discounting (DD) task has emerged as a reliable measure of impulsive behavior in the form of choice impulsivity (CI). Interestingly, studies that examined the effect of acute stress on DD performance reported mixed results. To address this, we conducted a within-subject examination of the impact of acute stress on CI, focusing on individual differences in response patterns. One hundred and fifty healthy female participants completed the DD task twice, before and after undergoing an acute laboratory stress induction procedure. Saliva samples and self-report mood and affect measures were collected at four time points throughout the session. Fifty-nine matched healthy control participants completed only the DD task twice, with no stress in between. Results indicate that the acute stress procedure elicited the expected effects of increased cortisol release and increased negative mood and affect, at the group level. With respect to DD, stress indeed increased CI at the group level, yet participants differed in the magnitude and direction of this effect. Interestingly, regression analysis revealed quadratic relations between stress-induced changes in CI and cortisol release. Indeed, dividing the sample into three sub-groups based on the impact of stress on CI revealed that, compared to participants that exhibited no substantial change in their CI following stress, participants that exhibited either stress-induced increase or decrease in their CI also exhibited more stress-induced cortisol release, as well as more negative affect. Taken together, these findings suggest that elevated physiological and psychological responses to stress are associated with either increased or decreased choice impulsivity, thus depicting quadratic relations between stress and impulsivity.

Acute stress amplifies experienced and anticipated regret in counterfactual decision-making

Previous research has shown that stress can affect emotion processing in a variety of settings. However, little attention has been paid to the effects of stress on emotional decision-making. The present study addressed this question by exposing healthy young participants either to a stressor (n = 30)-socially evaluated cold pressor task- or a non-stressful control task (n = 30). Subsequently, participants completed a computerized decision-making task in which they could compare the obtained factual outcome with a non-obtained counterfactual outcome. Saliva samples were taken at four time points over the course of the experiment and used to analyze cortisol levels. Results revealed that acute stress induced reliable salivary cortisol increase over the experimental task. At the outcome delivery stage, acute stress amplified negative emotions induced by the counterfactual comparison. At the choice stage, under stress, participants were more likely to make regret-averse decisions. The findings that acute stress amplifies both experienced and anticipated regret is consistent with dual process frameworks such that stress tilts decision-making toward more emotional and intuitive processing.Lay summaryStress is thought to affect emotional processing. The present study investigated the effects of acute stress on emotional decision making using a typical counterfactual decision making task. Acute stress amplified both experience and anticipation of regret, consistent with the dual process frame that stress tilts decision-making toward more emotional and intuitive processing.

A Meta-Analytic Review of Sex Differences on Delay of Gratification and Temporal Discounting Tasks in ADHD and Typically Developing Samples

Objective: To examine whether males and females with ADHD differ in their preferences for delayed rewards, since there is some evidence that suggests a sex difference with typically developing (TD) samples. Method: We used meta-analyses to examine sex differences on delay of gratification and temporal discounting tasks in both TD and ADHD samples. We identified 28 papers with 52 effect sizes for children and adults, and calculated the average effect size for sex comparisons within TD and ADHD samples. Results: The estimated mean difference between TD males and TD females was negligible, but males with ADHD were more likely to choose the larger delayed rewards than females with ADHD. Meta-regressions indicated that task type, age, and reward type did not significantly predict sex differences. Conclusion: These findings suggest that females referred for ADHD may make less adaptive choices by preferring smaller immediate rewards over larger delayed rewards more often than males with ADHD. Implications of our findings are discussed.

Effects of Dynamic Resilience on the Reactivity of Vagally Mediated Heart Rate Variability

Dynamic resilience is a novel concept that aims to quantify how individuals are coping while operating in dynamic and complex task environments. A recently developed dynamic resilience measure, derived through autoregressive modeling, offers an avenue toward dynamic resilience classification that may yield valuable information about working personnel for industries such as defense and elite sport. However, this measure classifies dynamic resilience based upon in-task performance rather than self-regulating cognitive structures; thereby, lacking any supported self-regulating cognitive links to the dynamic resilience framework. Vagally mediated heart rate variability (vmHRV) parameters are potential physiological measures that may offer an opportunity to link self-regulating cognitive structures to dynamic resilience given their supported connection to the self-regulation of stress. This study examines if dynamic resilience classifications reveal significant differences in vagal reactivity between higher, moderate and lower dynamic resilience groups, as participants engage in a dynamic, decision-making task. An amended Three Rs paradigm was implemented that examined vagal reactivity across six concurrent vmHRV reactivity segments consisting of lower and higher task load. Overall, the results supported significant differences between higher and moderate dynamic resilience groups' vagal reactivity but rejected significant differences between the lower dynamic resilience group. Additionally, differences in vagal reactivity across vmHRV reactivity segments within an amended Three Rs paradigm were partially supported. Together, these findings offer support toward linking dynamic resilience to temporal self-regulating cognitive structures that play a role in mediating physiological adaptations during task engagement.

Representation of the observer's predicted outcome value in mirror and nonmirror neurons of macaque F5 ventral premotor cortex

In the search for the function of mirror neurons, a previous study reported that F5 mirror neuron responses are modulated by the value that the observing monkey associates with the grasped object. Yet we do not know whether mirror neurons are modulated by the expected reward value for the observer or also by other variables, which are causally dependent on value (e.g., motivation, attention directed at the observed action, arousal). To clarify this, we trained two rhesus macaques to observe a grasping action on an object kept constant, followed by four fully predictable outcomes of different values (2 outcomes with positive and 2 with negative emotional valence). We found a consistent order in population activity of both mirror and nonmirror neurons that matches the order of the value of this predicted outcome but that does not match the order of the above-mentioned value-dependent variables. These variables were inferred from the probability not to abort a trial, saccade latency, modulation of eye position during action observation, heart rate, and pupil size. Moreover, we found subpopulations of neurons tuned to each of the four predicted outcome values. Multidimensional scaling revealed equal normalized distances of 0.25 between the two positive and between the two negative outcomes suggesting the representation of a relative value, scaled to the task setting. We conclude that F5 mirror neurons and nonmirror neurons represent the observer's predicted outcome value, which in the case of mirror neurons may be transferred to the observed object or action.NEW & NOTEWORTHY Both the populations of F5 mirror neurons and nonmirror neurons represent the predicted value of an outcome resulting from the observation of a grasping action. Value-dependent motivation, arousal, and attention directed at the observed action do not provide a better explanation for this representation. The population activity's metric suggests an optimal scaling of value representation to task setting.

Vulnerability to stress: Personality facet of vulnerability is associated with cardiovascular adaptation to recurring stress

It is increasingly suggested that personality traits are critical to understanding patterns of cardiovascular stress adaptation. However, studies have focused on higher-order traits with no research having examined underlying facet effects to repeated stress. The examination of facets provides a more granular examination, which has the potential to identify specific personality components that are relevant within the context of psychophysiological stress adaptation. This study objective was to determine if the underlying facets which encapsulate the dimension of emotional stability, are associated with cardiovascular adaptation to recurring stress. Continuous cardiovascular monitoring and psychometric measures were collated from 79 healthy young male and female adults, across a protocol of recurring active stress tasks. Multiple regression analysis revealed that the facet of vulnerability was associated with systolic and diastolic blood pressure adaptation across the protocol. More specifically, vulnerability was negatively associated with adaptation to recurring stress, such that those highest in vulnerability displayed a sensitization to the recurring stressor. No significant effects emerged for any other facet. Importantly, this research adds to the existing literature examining stress adaptation and has implications for future research on the relevance of examining facet effects. This study is the first to implicate the personality facet of vulnerability which encapsulates an individual's tendency to feel unable to cope with stress and becoming hopeless when faced with emergency situations, in the context of cardiovascular stress adaptation. Taken together, this study suggests that the facet of vulnerability is a critical component to consider in the context of cardiovascular stress adaptation.

The impact of Yohimbine-induced arousal on facets of behavioural impulsivity

RATIONALE

State-dependent changes in physiological arousal may influence impulsive behaviours.

OBJECTIVES

To examine the relationship between arousal and impulsivity, we assessed the effects of yohimbine (an α₂-adrenergic receptor antagonist, which increases physiological arousal via noradrenaline release) on performance on established laboratory-based impulsivity measures in healthy volunteers.

METHODS

Forty-three participants received a single dose of either yohimbine hydrochloride or placebo before completing a battery of impulsivity measures. Blood pressure and heart rate were monitored throughout the study.

RESULTS

Participants in the yohimbine group showed higher blood pressure and better response inhibition in the Stop Signal Task, relative to the placebo group. Additionally, individual changes in blood pressure were associated with performance on Delay Discounting and Information Sampling tasks: raised blood pressure following drug ingestion was associated with more far-sighted decisions in the Delay Discounting Task (lower temporal impulsivity) yet reduced information gathering in the Information Sampling Task (increased reflection impulsivity).

CONCLUSIONS

These results support the notion that impulsive behaviour is dependent upon state physiological arousal; however, distinct facets of impulsivity are differentially affected by physiological changes.

How do care staff in residential aged care facilities conceptualise their non-verbal interactions with residents with dementia and what relevance has this for how residents' preferences and capacity for decision-making are understood?

This paper considers the significance of how staff in residential aged care facilities interpret the non-verbal communication and behaviour of residents vis-a-vis their assessments of residents' preferences and ability to participate in decision-making. It highlights the risks associated with staff members' failure to interpret residents' non-verbal communication and behaviour with reference to residents' backgrounds and prior experiences. It also considers how non-verbal communication implemented by staff may impact residents' emotional state and, as a consequence, decision-making abilities. Drawing on interview data with aged care staff from Queensland and Victoria, it demonstrates that care staff in residential facilities appear to rely heavily on non-verbal signals in assessing the decision-making capacity and preferences of residents with dementia. It also indicates that many staff fail to consider residents' non-verbal communication and behaviour with due consideration of residents' individual histories.

Telomere length in alcohol dependence: A role for impulsive choice and childhood maltreatment

Telomere shortening, a marker of cellular aging, has been considered to be linked with psychosocial stress as well as with chronic alcohol consumption, possibly mediated by oxidative stress and inflammatory response. Recent findings suggested that early life adversity on telomere dynamics may be related to impulsive choice. To further our understanding of the association of impulsive choice and childhood trauma on telomere length, we examined whether delayed discounting and childhood trauma or their interaction is related to leukocyte telomere length, while controlling for multiple potential confounding variables, in patients with alcohol dependence who are considered to have higher impulsive choice and shorter telomere length. We recruited 253 male patients with chronic alcohol dependence. All participants performed the delay discounting task, and the area under curve was used as a measure of delay discounting. Steeper delay discounting represents more impulsive choices. The modified Parent-Child Conflict Tactics Scale was used to measure childhood maltreatment. In addition, confounding factors, including socio-demographic characteristics, the Alcohol Use Disorders Identification Test, the Buss-Perry Aggression Questionnaire, the Resilience Quotient, the Beck Depression Inventory, and the Beck Anxiety Inventory, were also assessed. Hierarchical regression analyses showed a significant main effect of delay discounting (β=0.161, t=2.640, p=0.009), and an interaction effect between delay discounting and childhood maltreatment on leukocyte telomere length (β=0.173, t=2.138, p=0.034). In subsequent analyses stratified by childhood maltreatment, patients with alcohol dependence and high childhood trauma showed a significant relationship between delay discounting and leukocyte telomere length (β=0.279, t=3.183, p=0.002), while those with low trauma showed no association between them. Our findings suggest that higher impulsive choice is associated with shorter telomere length, and childhood trauma may exert a moderating effect in the relationship between impulsive choice and telomere length.

Child Problems as a Moderator of Relations Between Maternal Impulsivity and Family Environment in a High-Risk Sample

OBJECTIVE

Previous studies have suggested that maternal characteristics are related to family environment; however, the relation between maternal impulsivity, in particular, and family environment is not well understood. As such, we examined direct relations between maternal impulsivity and family environment, as well as whether the relation between maternal impulsivity and family environment was moderated by child problems for sons and daughters. We hypothesized that child problems would moderate the association between maternal impulsivity and family environment. We also explored whether these associations differ for boys and girls.

METHOD

Data from the initial visit of a longitudinal study was used for the current study. Participants included 297 youth (137 boys; 160 girls) of 10 to 12 years of age (M = 10.99, SD = .84) and their mothers. The majority of the sample had a family history of substance use disorder (n = 236).

RESULTS

Hierarchical linear regressions showed that for sons there was a significant interaction between maternal impulsivity and child problems on family environment. Maternal impulsivity was positively related to family environment problems among sons with few emotional and behavioral problems, but there was no significant correlation among sons with high problem levels. Among daughters, there was no significant interaction between maternal impulsivity and child emotional and behavioral problems on family environment.

CONCLUSIONS

The results suggest that the association between maternal impulsivity and family environment may depend on problem level and child gender. Thus, addressing maternal impulsivity in therapy may benefit some families.

Stress-Induced Executive Dysfunction in GDNF-Deficient Mice, A Mouse Model of Parkinsonism

Maladaptive reactivity to stress is linked to improper decision making, impulsivity, and discounting of delayed rewards. Chronic unpredictable stress (CUS) alters dopaminergic function, re-shapes dopaminergic circuits in key areas involved in decision making, and impairs prefrontal-cortex dependent response inhibition and working memory. Glial-derived neurotrophic factor (GDNF) is essential for regulating dopamine (DA) release in the basal ganglia and for the survival of dopaminergic neurons; GDNF-deficient mice are considered an animal model for aging-related Parkinsonism. Recently, GDNF expression in the striatum has been linked to resilience to stress. Here we investigated the effects of CUS on decision making in GDNF-heterozygous (HET) mice and their wild-type littermate controls (WT). Before CUS no differences in temporal discounting (TD) were found between genotypes. However, following CUS GDNF HET mice, having a partial reduction of GDNF levels, showed increased impulsive choice indexed by a reduction in percent Larger-Later (LL) choices in the TD paradigm, and a reduction in area under the TD curve. Moreover, stressed GDNF HET mice, but not their WT controls, showed decreased neuronal activation (number of cFos positive neurons) in the orbitofrontal cortex (OFC), nucleus accumbens (NA) core, and NA shell, suggestive of a maladaptive response to stress. Interestingly, area under the TD curve positively correlated with cFos activation in the NA core, and NA shell, but not with orbitofrontal activity. These results provide further evidence of the differential involvement of the OFC, NA core, and NA shell in impulsive choice, and identify GDNF-deficient mice as a double-hit (gene × environment) model of stress-related executive dysfunction, particularly relevant to substance abuse and Parkinson’s disease (PD).

Blunted cardiac stress reactors exhibit relatively high levels of behavioural impulsivity

Blunted physiological reactions to acute psychological stress are associated with a range of adverse health and behavioural outcomes. This study examined whether extreme stress reactors differ in their behavioural impulsivity. Individuals showing blunted (N=23) and exaggerated (N=23) cardiovascular reactions to stress were selected by screening a healthy student population (N=276). Behavioural impulsivity was measured via inhibitory control and motor impulsivity tasks. Blunted reactors exhibited greater impulsivity than exaggerated reactors on both stop-signal, F(1,41)=4.99, p=0.03, ηp(2)=0.108, and circle drawing, F(1,43)=4.00, p=0.05, η p(2)=0.085, tasks. Individuals showing blunted cardiovascular stress reactions are characterized by greater impulsivity which may contribute to their increased susceptibility to outcomes such as obesity and addiction.

A Computational Analysis of Aberrant Delay Discounting in Psychiatric Disorders

Impatience for reward is a facet of many psychiatric disorders. We draw attention to a growing literature finding greater discounting of delayed reward, an important aspect of impatience, across a range of psychiatric disorders. We propose these findings are best understood by considering the goals and motivation for discounting future reward. We characterize these as arising from either the opportunity costs of waiting or the uncertainty associated with delayed reward. We link specific instances of higher discounting in psychiatric disorder to heightened subjective estimates of either of these factors. We propose these costs are learned and represented based either on a flexible cognitive model of the world, an accumulation of previous experience, or through evolutionary specification. Any of these can be considered suboptimal for the individual if the resulting behavior results in impairments in personal and social functioning and/or in distress. By considering the neurochemical and neuroanatomical implementation of these processes, we illustrate how this approach can in principle unite social, psychological and biological conceptions of impulsive choice.

Differential cardiovascular and hypothalamic pituitary response to amphetamine in male pathological gamblers versus healthy controls

Cardiovascular and hypothalamic pituitary axis (HPA) disturbances have been observed in individuals who are pathological gamblers (PGs). These may partly derive from chronic exposure to gambling. Response to amphetamine (AMPH) may reveal such disturbances while controlling for differential conditioned responses to gambling in PGs vs healthy controls (HCs). This study assessed heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) and plasma cortisol following oral AMPH (0.4 mg/kg) in male PGs (n=12) and HCs (n=11) who underwent a positron emission tomography (PET) scan. The Stop Signal Task enabled assessment of the link between physiological and behavioral dysregulation. Trait moderating effects were explored. The responses of PGs to AMPH differed from those of HCs on every index. PGs displayed persistent elevation in DBP and concomitant reduction in HR (i.e. baroreflex) compared to HCs beyond 90 min post-dose. PGs displayed deficits in cortisol compared to HCs that were partially reversed by AMPH. Impairment on the Stop Signal Task correlated positively with HR in controls, but negatively with HR in PGs, suggesting that strong initial and compensatory cardiac responses to a stimulant may each predict disinhibition. Extraversion predicted greater disinhibition in PGs. Noradrenergic disturbances may contribute to sensitized responses to stimulant challenge and disinhibition in PGs.

The behavioral economics of substance use disorders: reinforcement pathologies and their repair

The field of behavioral economics has made important inroads into the understanding of substance use disorders through the concept of reinforcer pathology. Reinforcer pathology refers to the joint effects of (a) the persistently high valuation of a reinforcer, broadly defined to include tangible commodities and experiences, and/or (b) the excessive preference for the immediate acquisition or consumption of a commodity despite long-term negative outcomes. From this perspective, reinforcer pathology results from the recursive interactions of endogenous person-level variables and exogenous environment-level factors. The current review describes the basic principles of behavioral economics that are central to reinforcer pathology, the processes that engender reinforcer pathology, and the approaches and procedures that can repair reinforcement pathologies. The overall goal of this review is to present a new understanding of substance use disorders as viewed by recent advances in behavioral economics.

Rated and measured impulsivity in children is associated with diminished cardiac reactions to acute psychological stress

This study examined the association between impulsivity and heart rate reactions to a brief psychological stress in pre-adolescent children. Impulsivity was assessed by two response inhibition tasks and maternal self-report. Heart rate was measured at rest and in response to a mental arithmetic challenge. Children high in impulsivity showed blunted cardiac stress reactions. This result resonates with previous findings that blunted stress reactivity is characteristic of a range of problematic behaviours often associated with impulsivity.

The biological effects of acute psychosocial stress on delay discounting

Organisms prefer to receive rewards sooner rather than later because they excessively discount the subjective value of future rewards, a phenomenon called delay discounting. Recent studies have reported an association between cortisol-which is secreted by the hypothalamic-pituitary-adrenal (HPA) axis-and delay discounting. However, no study has examined whether acutely induced psychosocial stress modulates delay discounting. Thus, the present study examined the effect of acute psychosocial stress and its hormonal and inflammatory correlates on the rate of delay discounting. To accomplish this purpose, we assessed the participants' discounting rates using the questionnaire version with inter-temporal choice before and after an acute psychosocial stress task (the Trier Social Stress Test; TSST). The results demonstrated that TSST increased rates of delay discounting in only cortisol responders (not in non-responders), indicating the possible influence of the pathway from the HPA axis to the dopaminergic systems under acute stress. Furthermore, the findings of correlation analysis indicated a U-shaped relationship between baseline level of C-reactive protein and delay discounting rate, suggesting a complex relationship between inflammatory markers and delay discounting rate.

The neurobiological effects of stress on adolescent decision making

Relative to other developmental periods, adolescence is characterized by risky decision making, increased perceived stress and heightened reactivity to acute stress. It is also during this time that individuals undergo significant neurodevelopment in brain regions that process decision making and stress. In this review, we summarize what is currently known about stress during adolescence, how it impacts risky decision-making, and how acute stress may exert neurobiological effects on circuitry that subserves decision-making in the developing brain. We conclude by suggesting future research directions that may help the field gain traction on this important, but relatively understudied, question.

Acute stress induces selective alterations in cost/benefit decision-making

Acute stress can exert beneficial or detrimental effects on different forms of cognition. In the present study, we assessed the effects of acute restraint stress on different forms of cost/benefit decision-making, and some of the hormonal and neurochemical mechanisms that may underlie these effects. Effort-based decision-making was assessed where rats chose between a low effort/reward (1 press=2 pellets) or high effort/reward option (4 pellets), with the effort requirement increasing over 4 blocks of trials (2, 5, 10, and 20 lever presses). Restraint stress for 1 h decreased preference for the more costly reward and induced longer choice latencies. Control experiments revealed that the effects on decision-making were not mediated by general reductions in motivation or preference for larger rewards. In contrast, acute stress did not affect delay-discounting, when rats chose between a small/immediate vs larger/delayed reward. The effects of stress on decision-making were not mimicked by treatment with physiological doses of corticosterone (1-3 mg/kg). Blockade of dopamine receptors with flupenthixol (0.25 mg/kg) before restraint did not attenuate stress-induced effects on effort-related choice, but abolished effects on choice latencies. These data suggest that acute stress interferes somewhat selectively with cost/benefit evaluations concerning effort costs. These effects do not appear to be mediated solely by enhanced glucocorticoid activity, whereas dopaminergic activation may contribute to increased deliberation times induced by stress. These findings may provide insight into impairments in decision-making and anergia associated with stress-related disorders, such as depression.