Chronic work stress and decreased vagal tone impairs decision making and reaction time in jockeys

The effects of work on cognitive functions: a systematic review

Introduction

Cognitive functions play a crucial role in individual's life since they represent the mental abilities necessary to perform any activity. During working life, having healthy cognitive functioning is essential for the proper performance of work, but it is especially crucial for preserving cognitive abilities and thus ensuring healthy cognitive aging after retirement. The aim of this paper was to systematically review the scientific literature related to the effects of work on cognitive functions to assess which work-related factors most adversely affect them.

Method

We queried the PubMed and Scopus electronic databases, in February 2023, according to the PRISMA guidelines (PROSPERO ID number = CRD42023439172), and articles were included if they met all the inclusion criteria and survived a quality assessment. From an initial pool of 61,781 papers, we retained a final sample of 64 articles, which were divided into 5 categories based on work-related factors: shift work (n = 39), sedentary work (n = 7), occupational stress (n = 12), prolonged working hours (n = 3), and expertise (n = 3).

Results

The results showed that shift work, occupational stress, and, probably, prolonged working hours have detrimental effects on cognitive functioning; instead, results related to sedentary work and expertise on cognitive functions are inconclusive and extremely miscellaneous.

Discussion

Therefore, workplace health and well-being promotion should consider reducing or rescheduling night shift, the creation of less demanding and more resourceful work environments and the use of micro-breaks to preserve workers' cognitive functioning both before and after retirement.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023439172, identifier CRD42023439172.

Used like Pawns or Treated like Kings? How Narratives around Racehorse Welfare in the 2023 Grand National May Affect Public Acceptance: An Informed Commentary

The 2023 Grand National steeplechase race was delayed when protesters from the animal rights group, 'Animal Rising', gained access to the course just prior to the race. The international media spotlight was focused on what is already a high-profile event and the social licence of both this race and racing in general was scrutinised. Both at the time and for several days afterwards, the general public was exposed to two different narratives from pro- and anti-racing communities. This paper discusses these perspectives and the potential impact on the general public's relationship with racing. Whilst well-meaning and aiming to promote racing, much of the racing industry's commentary inadvertently risked damaging its reputation due to a poor understanding of social licence principles. We explore the reasons for these two groups' alternative perspectives on welfare and suggest considerations for change. Ultimately, if 'the people's race' is to maintain its social licence, the racing community needs to both understand and embrace the concept. Welcoming independent opinions, engaging with different viewpoints, accepting that change is inevitable and, most importantly, being proactive in making changes to prioritise equine welfare will all help racing to move towards greater public acceptance.

Evaluating High and Low Heart Rate Variability Response and Neurocognitive Performance in Workers: An Exploratory Study

Heart rate variability (HRV) has the potential to be a predicting factor of cognitive performance. The present research aimed to explore the differences in neurocognitive performance of workers with high HRV and low HRV. A total of 48 white-collar workers and 53 blue-collar workers were assessed. An electrocardiogram was used to obtain HRV data, whereby a 10 min baseline and an active (neuropsychological task) recording were taken. Median splits were performed on data to obtain high- and low-HRV groups. The Cambridge Neuropsychological Test Automated Battery, specifically, the spatial working memory, attention-switching task, rapid visual processing, and spatial span were used. Higher HRV (RMSSD and HF) was linked to better neurocognitive performance measures. Interestingly, the blue- and white-collar groups exhibited different correlations and, in some cases, showed an inverse relationship with the same variables. The differences observed in the present study demonstrate the importance of assessing task-dependent HRV parameters.

Sustainability and the Thoroughbred Breeding and Racing Industries: An Enhanced One Welfare Perspective

As society debates the use of animals in sport, entertainment, and leisure, there is an increasing focus on the welfare, social, and ecological impacts of such activities on the animals, human participants, people close to them, and the physical environment. This article introduces the "Enhanced One Welfare Framework" to reveal significant costs and benefits associated with Thoroughbred breeding and racing globally. In addition, relative to calls to ban horseracing and similar activities as part of sustainability approaches that focus chiefly on animals, the "Enhanced One Welfare Framework" is better positioned politically to guide discussions that renegotiate the conditions under which horses are used for sport and the impact racing has on humans and the planet. In 2020, the International Federation of Horseracing Authorities issued its minimum horse welfare standards based on the Five Domains model, positioning lifelong horse welfare as "fundamentally important to the viability and sustainability of the industry". In this article, we critique the One Welfare framework's historic lack of focus on sport and enhance it by including sport, leisure, and entertainment and framing it within the Five Domains model. We offer a novel extension of the Five Domains model beyond animal welfare to consider human welfare and the physical environmental impacts of the sport, leisure, and entertainment industries and propose innovations that may help thoroughbred breeding and racing assure a sustainable future.

Gender and Workplace Stress Affect the Association Between Concussion History and Depression Symptoms in Professional Jockeys

Objective

Professional jockeys experience high rates of concussion, workplace stress, and poor mental health. The present cross-sectional study, for the first time, concurrently assessed the potential interplay between concussion history and workplace stress with current depression symptoms.

Method

Seventy-two professional flat-track jockeys (male = 49, female = 23) were grouped based on self-reported concussion history (CG; n = 56) and those who did not report a concussion history (NCG; total n = 16). Analyses featured both between (CG vs NCG) and within group (CG only) assessment on self-reported measures of workplace stress and depression symptoms (affect, daily functioning).

Results

Jockeys in the CG had more symptoms of negative affect than the NCG. This association, however, was nonsignificant after covarying for age, gender, and workplace stress. Higher workplace stress (p = .005) and gender (p = .001) were associated with poorer daily functioning after controlling for concussion history (CG vs. NCG) and age. Gender moderated the association between concussion group and poorer daily functioning (β = −18.739, t (71) = −2.924, p = .005), with the difference between CG and NCG significant for females, but not males (β = 33.648, t (71) = 3.420, p = .001).

Conclusions

The findings provide preliminary evidence that previously concussed females may be more likely to report poorer daily functioning than males with a history of concussion, and that workplace stress may reduce the association between a history of concussion and depression symptoms. Prospective studies are required to validate and extend these findings.

Resting-state heart rate variability (HRV) mediates the association between perceived chronic stress and ambiguity avoidance

Chronic stress is associated with profound behavioral and physiological alterations, including intolerance to uncertainty and reduced resting-state heart-rate-variability (HRV). Critically, uncertainty may arise in situations with known probabilities (risk) or unknown probabilities (ambiguity). Whether associations between chronic stress and decision-making under uncertainty are dependent on the specific type of uncertain decisions, and whether physiological alterations play a role in these putative associations is not yet clear. Here, ninety-two healthy adults that exhibit various levels of perceived chronic stress underwent resting-state HRV recording before completing a behavioral task that involves decision-making under either risk or ambiguity. Computational modelling quantified participants' behavioral attitudes of approach and avoidance separately for risk and ambiguity. Results indicate, as expected, that perceived chronic stress is positively associated with intolerance to uncertainty and negatively associated with resting-state HRV. Contrary to expectations, behavioral attitudes towards risk and ambiguity were not directly associated with perceived chronic stress, yet HRV fully mediated the association between chronic stress and ambiguity avoidance. Taken together and given the direction of the associations, elevated HRV despite chronic stress may foster adaptive behavior in the form of avoiding ambiguous situations, and hence contribute to reduced exposure to uncertainty and to lower levels of allostatic load.

Salivary hormone concentrations and technical-tactical performance indicators in beach volleyball: Preliminary evidence

The present study aimed to investigate (i) differences in salivary testosterone and cortisol concentrations before, during, and after simulated beach volleyball match, depending on match outcome (winning vs. losing); (ii) the relationship between technical-tactical performance indicators in beach volleyball and salivary hormonal concentrations (i.e., testosterone, cortisol). We hypothesized (i) salivary testosterone concentrations would be greater in winners and salivary cortisol would be lower; (ii) testosterone would associate with positive technical-tactical performance and cortisol would associate with negative technical-tactical performance. Sixteen athletes participated in the study and were grouped according to the result of a simulated game (winners: n = 8; losers: n = 8). Salivary hormone concentration of testosterone and cortisol were measured by enzyme-linked immunosorbent assay (pre-match, post first set, and post-match), and the coefficient of performance and efficiency were used as technical-tactical performance indicators. Regarding testosterone, there was a large effect size for match outcome after the first set (i.e., Winner vs. Losers) and a moderate effect size for the time in winners (pre-match vs. post-match). Regarding cortisol, there was a moderate effect size of time in losers only (pre-match vs. post-match). Moreover, cortisol pre-match was negatively correlated with the offensive performance (attack performance coefficient: r = −0.541; p = 0.030; attack efficiency: r = −0.568; p = 0.022). In conclusion, the effect of match outcome on testosterone and cortisol levels was moderate in winners and losers, respectively. Moreover, resting cortisol concentration appears to be related to a diminished attack technical-tactical performance. However, larger confirmatory studies are required to confirm these data to corroborate winning increases testosterone levels and/or reduces cortisol in a sporting setting.

Occupational stress in industry setting in Benin 2019: A cross-sectional study

Background

Occupational stress is a psychosocial risk in the workplace. Working conditions in industrial settings may lead to occupational stress. In Benin, however, there is little epidemiological data on occupational stress in industrial settings. We aimed to determine the prevalence and factors associated with occupational stress in industrial settings in Benin in 2019.

Methods

This was a prospective, cross-sectional study conducted from January 31 to April 11, 2019, among 15 cotton ginning plants. Sampling was exhaustive for permanent workers and stratified in clusters by shift for occasional cotton gin workers. Data were collected through Karasek and Siegrist questionnaires. Data analysis was performed using R software. Binary multivariable logistic regression was performed. The significance level was p < 0.05.

Results

Of 1883 workers included, 90.8% were male. The median age was 38 years (IQR: 28 years to 49 years). The prevalence of occupational stress was 77.7% (95% CI: 75.8–79.6). Psychological demand was high in 93.0% of workers and 83.9% had low decision latitude. Among the workers, 16.3% had low social support and 89.9% had a low recognition score at work. Factors associated with occupational stress were: being an occasional vs. permanent worker (aOR 6.43, 95% CI 4.18 to 9.88); age less than 38 years (aOR 0.55, 95% CI 0.41 to 0.76); high intensity physical activity at work (aOR 1.33, 95% CI 1.03 to 1.73); working in production vs. administration (aOR 1.59, 95% CI 1.03 to 2.45); spending fewer than 4 years at the current work location (aOR 1.60, 95% CI 1.05 to 2.44); and scoring low for recognition at work (aOR 1.53, 95% CI 1.04 to 2.23). Noise exposure and being a shift worker were significant in univariable analysis, but not multivariable analysis.

Conclusion

Occupational stress is very common among workers in industrial settings. The implementation and evaluation of preventive measures against these risk factors is necessary.

Within subject rise in serum TNFα to IL-10 ratio is associated with poorer attention, decision-making and working memory in jockeys

Jockeys work in high-risk environments that rely heavily on attention- and decision-making to perform well and safely. Workplace stress literature has often overlooked the impact of stress on cognition, and designs that include physiological measures are rare. This study assessed the prospective concurrent relationships between workplace stress, depression symptoms and low-grade inflammation with cognitive performance among professional jockeys. Professional jockeys (N = 35, M_age = 32.29) provided information on workplace stress and depression symptoms, with serum levels of inflammatory cytokines (IL-6, IL-10, TNFα) and cytokine balance (IL-6: IL-10, TNFα: IL-10) quantified with SIMOA, and cognitive performance with CogSport computer-based testing battery. These measures were repeated after a twelve-month interval. Increased workplace stress between testing intervals was associated to an increased cytokine imbalance (β = 0.447, p = .015) after controlling for age and gender. Increases in cytokine imbalance occurred in unison with decreases in attention (β = 0.516, p = .002), decision-making (β = 0.452, p = .009) and working memory (β = 0.492, p = .004). These preliminary findings suggest the underlying mechanisms linking workplace stress and reduced cognitive performance may be influenced by measures of low-grade inflammation and specifically a cytokine imbalance. Our findings suggest a measure of cytokine balance may explain the heterogenous findings in previous studies that have focussed solely on the association of workplace stress with pro-inflammatory cytokines. Future work is needed however, to provide a broader evidence-base for our claims to better inform designs to intervene in the higher workplace stress-poorer cognition relationship.

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Increases in workplace stress are associated with increased cytokine imbalance.

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Increased cytokine imbalance is associated with reduced cognitive performance.

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Workplace stress better predicts cytokine imbalance than individual cytokines.

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Cytokine imbalance better predicts cognition than individual cytokines.

Objective assessment of mental stress in individuals with different levels of effort reward imbalance or overcommitment using heart rate variability: a systematic review

BACKGROUND

Workloads are increasing and could cause mental stress, e.g., in the form of subjective effort reward imbalance (ERI) and overcommitment (OC). The heart rate variability (HRV) is a valid method for objective monitoring of workload. The aim of this project is to systematically evaluate the literature on HRV as an objective indicator for mental stress in individuals with different levels of ERI or OC.

METHODS

A systematic literature review examining HRV of employees in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement for reporting systematic reviews was performed. Electronic databases used were PubMed, Ovid, Cochrane Libary, Scopus and Web of Science, PsyInfo, Psyndex, and Livio. Only articles from 2005 to 2021 were included. Inclusion criteria were case-control studies, intervention studies, cross-sectional studies, or longitudinal studies with different levels of ERI and/or OC, >10 participants in each group, measurement of 24h HRV by using Holter ECG or chest belt, and full-text in English or German language. The methodological quality was evaluated by using a modified STARD for HRV.

RESULTS

Five studies matched the inclusion criteria by using HRV (24-h ECG) with a different HRV analysis at day and night. It showed an adaptation of HRV with higher ERI or OC with reduced parasympathetic HRV parameters, but the studies were not comparable.

CONCLUSIONS

There is a need for occupational health studies that examine strains and stress of different employees with predominantly mental stress. The well-established parasympathetic mediated HRV parameters seem to be suitable parameters to objectify the stress.

Feasibility of Volitional Reaction Time Tests in Athletes: A Systematic Review

This systematic review aimed to synthesize the current evidence on the feasibility of volitional reaction time (RT) tests to evaluate the information processing abilities of athletes. Four databases were searched, and, finally, 38 studies exploring the reliability, validity, or sensitivity of RT tests were included. Seven studies explored the reliability, which ranged from poor to excellent, while only three studies explored the validity of RT tests. The most important downside of the majority of the implemented RT tests is their nonspecific nature (i.e., stimulus and response did not resemble the sports actions). Sports scientists should focus on developing RT tests that are specific for each sport and refine the testing procedures to obtain accurate, reproducible, and sensitive measurements of RT.

Gender moderates the association between chronic academic stress with top-down and bottom-up attention

Research on the relationship between chronic stress and cognition is limited by a lack of concurrent measurement of state-anxiety, physiological arousal, and gender. For the first time, we assessed the impact of these factors on top-down/conscious (simple and choice reaction time) and bottom-up/reflexive (saccadic reaction time) measures of attention using CONVIRT virtual-reality cognitive tests. Participants (N = 163) completed measures of academic stress (effort-reward imbalance; ERI) and state-anxiety while heart-rate variability was recorded continuously throughout the experiment. Gender moderated the association between academic stress with the top-down measures (b = -0.002, t = -2.023, p = .045; b = -0.063, t = -3.080, p = .002) and higher academic stress was associated with poorer/slower reaction times only for male participants. For bottom-up attention, heart rate variability moderated the relationship between academic stress and saccadic reaction time (b = 0.092, t = 1.991, p = .048), and only female participants who were more stressed (i.e., ERI ≥ 1) and displayed stronger sympathetic dominance had slower reaction times. Our findings align with emerging evidence that chronic stress is related to hyperarousal in women and cognitive decrements in men. Our findings suggest that higher ERI and sympathetic dominance during cognitive testing was associated with poorer bottom-up attention in women, whereas for men, academic stress was related with poorer top-down attention irrespective of sympathovagal balance.

Physical activities of jockeys during a working week

Horse racing and training is a physically demanding sport. The aims of this study were to quantify the physical activities of jockeys during a working week and to investigate self-reported fall and injury incidence rates of jockeys at work. A daily workload diary examining workday and physical activities was emailed to all jockeys licensed to ride in a race in New Zealand in 2020. Sixty-three jockeys (25 apprentices, 33 professional and 5 amateur riders) began the diary, representing 38% of the licensed population of jockeys in New Zealand. Jockeys worked a median of 44 (interquartile range (IQR) 33-57) hours, 6-days per week. A median of 7 (IQR 6-9) horses were ridden per day, comprising 58% of work time, with 11 (IQR 7-15) hours per week spent at training pace. Elite jockeys (high performance in the premiership table) spent more time riding in races (1.1, IQR 0.7-1.2 hours per week) than non-elite jockeys (0.0, 0.0-0.4, P=0.01), with 29% (IQR 0-54%) of their weekly rides as race rides. Extra physical training was conducted by 72% of jockeys, which consisted mainly of low intensity exercise such as pleasure riding (56%) and walking (43%). Falls during morning exercise work were recorded by 87% of respondents, 40% of which had sustained an injury in the previous 12 months. Jockeys who participated in extra physical training had higher fall incidence rates per 1000 horses ridden in morning exercise work (3.5, 95% confidence interval (CI) 3.1-3.9, P=0.002) but lower fall incidence rate in race riding (2.1, 95% CI 1.5-2.8, P<0.001) than jockeys who did no extra training (2.5, 95% CI 2.0-3.0 and 5.9, 95% CI 3.8-9.0). Elite jockeys experience a level of specific race exercise which is lacking in the other jockeys.

Associations between chronic work stress and plasma chromogranin A/catestatin among healthy workers

OBJECTIVES

Plasma chromogranin A (CgA) may play a critical role on linking work stress to health outcomes. The aim of our study was to investigate the associations between work stress and plasma CgA levels in healthy workers without chronic diseases.

METHODS

The study included 260 healthy workers from EHOP study. Work stressors were assessed by the Chinese version of the 23-item ERI-Q questionnaire. Plasma CgA and catestatin levels were measured by ELISA kits. The demographic characteristics were collected from medical records.

RESULTS

Among the final 260 subjects including 173 males (66.5%) and 87 females (33.5%), the average age was 37.6 ± 10.6 years old. Effort, overcommitment, and ERI were positively associated with plasma CgA level, respectively (r = 0.267, 0.319, and 0.304, all p < .001), while reward was negatively associated with CgA level (r = -0.237, p < .001). The workers with high effort, overcommitment, or ERI had significantly higher plasma CgA levels, while the workers with high rewards had significantly lower plasma CgA levels. The workers with both high overcommitment and high ERI had highest plasma CgA levels. In the linear regression analysis, after adjustment for confounders, effort, overcommitment, and ERI were respectively positively related to plasma CgA, while reward negatively related to plasma CgA. The associations between work stress and plasma catestatin was not significant. The ratio of CgA and catestatin was associated with work stress.

CONCLUSIONS

Work stress is associated with plasma CgA which may be play a crucial role on the pathway from chronic work stress to cardiovascular diseases.

The effects of acute and chronic stress on choice consistency

Important decisions are often made under some degree of stress. It is now well-established that acute stress affects preferences and priorities in our decisions. However, it is hard to make a general case on the net impact of stress on decision-making quality in a normative sense as evidence for or against a direct effect of stress on decision-making quality is sparse. Here, we used the revealed preference framework of choice consistency to investigate decision-making quality without the assumption of an objectively correct choice. Specifically, we tested whether acute stress influences choice consistency in a time dependent fashion. A sample of 144 participants solved a food choice task before, immediately after and in the aftermath of the Trier Social Stress Test (TSST) or a matched control procedure. We confirmed the effectiveness of our stress manipulation via an array of subjective and physiological stress measures. Using Bayesian statistics, we found strong evidence against an effect of acute stress on choice consistency. However, we found exploratory evidence for a negative association of self-reported chronic stress and choice consistency. We discuss our results in the context of previous findings of stress effects on choice consistency and preference changes.

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.

Review of physical fitness, physiological demands and performance characteristics of jockeys

This narrative review collates data from different equestrian disciplines, both amateur and professional, to describe the physiological demands, muscle activity and synchronicity of movement involved in jockeys riding in a race and to identify limitations within our current knowledge. A literature search was conducted in Web of Science, Google Scholar, PubMed and Scopus using search terms related to jockeys, equestrian riders and their physiological demands, muscle use, movement dynamics and experience. Abstracts, theses and non-peer reviewed articles were excluded from the analysis. Jockeys work at close to their physiological capacity during a race. The quasi-isometric maintenance of the jockey position requires muscular strength and endurance, specifically from the legs and the core, both to maintain their position and adapt to the movement of the horse. Synchronous movement between horse and rider requires a coordinated activation pattern of the rider’s core muscles, resulting in less work done by the horse to carry the rider, possibly leading to a competitive advantage in race riding. Reports of chronic fatigue in jockeys demonstrate poor quantification of workload and recovery. The lack of quantitative workload metrics for jockeys’ limits calculation of a threshold required to reach race riding competency and development of sport-specific training programmes. Until the sport-specific demands of race riding are quantified, the development of evidence-based sport specific and potentially performance enhancing jockey strength and conditioning programmes cannot be realised.

Racing to a staffing solution: an investigation into the current staffing crisis within the UK horseracing industry

The British Horseracing Industry has been experiencing a labour shortage since the 1970’s and despite recent improvements reported in staff retainment, the industry still reports high staff turnover. We investigated staffing challenges experienced by UK horseracing employers and employees, to formulate strategic targets to address any issues identified. Thirty UK trainers and staff (12 staff, 9 senior staff, 9 trainers) participated in semi-structured inductive focus groups lasting on average 39±9 min. Questions explored staff background in racing, perceptions of the current staff challenges, retention and recommendations for improvement. Thematic analysis revealed four higher order themes; (1) lack of skills, (2) differences in perceived work ethic, (3) job conditions, and (4) media portrayal. This study concluded that there are dedicated staff working in the industry, but significant skills gaps, high workloads, poor work-life balance and a lack of training and career progression negatively influence retention in the horseracing industry.

Brain-derived Neurotropic Factor val66met is a Strong Predictor of Decision Making and Attention Performance on the CONVIRT Virtual Reality Cognitive Battery

The val66met polymorphism of the brain-derived neurotrophic factor gene has been associated with changes in components of executive functioning such as decision making; however, this relationship remains unclear. Val66met-related changes in attention and visual processing speed may explain potential changes in decision making. Furthermore, chronic stress disrupts executive functions and alters autonomic activity. Because the relationship between val66met and cognition has not been investigated in the context of chronic stress or stress-related autonomic changes, in this study 55 healthy university students completed self-report measures of chronic stress and mental health. Participants then completed a virtual reality cognitive test battery (CONVIRT) measuring decision making, attention, and visual processing reaction times. To measure autonomic activity, saliva alpha amylase and heart rate variability (HRV) were assessed at baseline and after CONVIRT testing. Saliva samples were used to identify val66met genotype. Regression analyses demonstrated that val66met was the strongest predictor of decision making and attention, but not visual processing, where valine/methionine (Val/met) participants had faster reaction times than Val/val participants. Val/met participants also had higher perceived chronic stress and heightened increases in sympathetic activity, but not parasympathetic activity. Neither stress nor autonomic activity moderated the effect of val66met on decision making or attention. This study is the first to investigate the role of val66met in decision making, attention, and visual processing while taking into account chronic stress and autonomic activity. This multifactorial approach revealed that carriers of the Val/met genotype may have better decision making and attention than Val/val carriers.

Assessing the Long-Term Impact of Concussion upon Cognition: A 5-Year Prospective Investigation

OBJECTIVE

Jockeys have high rates of concussion, with 5% of jockeys receiving at least one concussion annually. The impact of acute concussion upon cognition is well understood, but less is known about the long-term effects of concussion upon cognition. Our aim was to assess the impact of concussion upon jockeys who had provided pre-concussion assessments of cognition using a prospective design.

METHOD

In this study, over a 5-year period, we assessed the cognitive performance of jockeys with ≥1 medically diagnosed concussion (MDC; n = 17, months since concussion, M = 29.18), against those who had not been concussed (NC; n = 41). Jockeys who had not been concussed in the preceding 6 months completed four computer-based cognitive assessments from the CogSport battery.

RESULTS

Unlike the majority of the small existing literature, there was no difference (p ≥ .05) between the MDC and NC groups after controlling for age and baseline performance. Additionally, we used a measure of reliable change to assess for clinically meaningful decrements from baseline in each test and composite score 5 years later. None of the jockeys in the MDC group recorded significant decrements on any CogSport measure from baseline (z > -1.65).

CONCLUSIONS

The findings suggest that the presence of concussion does not result in persistent decrements in cognitive performance and that when findings are considered collectively, assessing factors beyond medically diagnosed concussion (e.g., chronic stress, undiagnosed concussion) may improve the interpretation of our current findings.

Development of a new virtual reality test of cognition: assessing the test-retest reliability, convergent and ecological validity of CONVIRT

Background

Technological advances provide an opportunity to refine tools that assess central nervous system performance. This study aimed to assess the test-retest reliability and convergent and ecological validity of a newly developed, virtual-reality, concussion assessment tool, ‘CONVIRT’, which uses eye-tracking technology to assess visual processing speed, and manual reaction time (pushing a button on a riding crop) to assess attention and decision-making. CONVIRT was developed for horse jockeys, as of all sportspersons, they are most at risk of concussion.

Methods

Participants (N = 165), were assessed with CONVIRT, which uses virtual reality to give the user the experience of riding a horse during a horserace. Participants were also assessed with standard Cogstate computer-based concussion measures in-between two completions of the CONVIRT battery. The physiological arousal induced by the test batteries were assessed via measures of heart rate and heart rate variability (LF/HF ratio).

Results

Satisfactory test-retest reliability and convergent validity with Cogstate attention and decision-making subtests and divergent validity in visual processing speed measures were observed. CONVIRT also increased heart rate and LF/HF ratio, which may better approximate participant arousal levels in their workplace.

Conclusions

CONVIRT may be a reliable and valid tool to assess elements of cognition and CNS disruption. The increased ecological validity may also mean better informed ‘return-to-play’ decisions and stronger industry acceptance due to the real-world meaningfulness of the assessment. However, before this can be achieved, the sensitivity of the CONVIRT battery needs to be demonstrated.

Assessing the association of university stress and physiological reactivity with decision-making among students

Compared with age-matched employees, university students report higher levels of chronic stress and this may affect their decision-making. The impact of chronic stress and physiological reactivity upon cognitive function is receiving more attention, but few studies have empirically assessed the associations of these variables concurrently. Our aim was to investigate if chronic student stress, as assessed by effort-reward imbalance (ERI) and overcommitment, and physiological reactivity, were related to decision-making. As measures of physiological reactivity, we collected salivary alpha-amylase (sAA) and continuously recorded heart rate variability (HRV) data from male students (n = 79) at pretest and immediately after some computerized decision-making tasks (simple and choice- reaction times). Our findings suggest that students who are higher in overcommitment and who are more physiologically reactive (sAA and HRV indices) at the pretest stage may be more "at-risk" of poor decision-making than others. If others can replicate our findings in more diverse samples, this will contribute to an evidence base for interventions targeted at reducing overcommitment, ERI, and dysregulated autonomic reactivity to improve decision-making.

Emerging Issues in Occupational Disease: Mental Health in the Aging Working Population and Cognitive Impairment-A Narrative Review

Cognitive impairment has often been reported in scientific literature as a concern derived from chronic exposure to work-related stress. Organizational factors can contribute to the onset of this concern especially in a susceptible population such as elderly workers. The aim of our study was to review the last five years of scientific literature, focusing on experimental and epidemiological studies, possible mechanisms implicated in the onset of cognitive decline due to work-related stress, and the recent organizational strategies to prevent detrimental effects of stress on cognitive processes. A literature search was performed in scientific platforms Medline and Web of Science, by means of specific string search terms, restricting the search to the years of publication 2014-2019. Thirty-three articles were identified and qualitatively evaluated, reporting narratively the main point of interest. At this stage, six articles were excluded because they did not meet the inclusion criteria. Only a few articles considered the population of the elderly workers, often with a short follow-up period. Strategies to manage stress with organizational procedures are scarce. Mechanisms implicated in the development of cognitive impairment due to stress are not fully explained and seem to include a chronical decrease in the inhibitory process of neurological pathways. Further research that focused on strategies to manage stress in elderly workers, with the aim of preventing cognitive impairment processes, is warranted.

Work-Related Stress, Physio-Pathological Mechanisms, and the Influence of Environmental Genetic Factors

Work-related stress is a growing health problem in modern society. The stress response is characterized by numerous neurochemicals, neuroendocrine and immune modifications that involve various neurological systems and circuits, and regulation of the gene expression of the different receptors. In this regard, a lot of research has focused the attention on the role played by the environment in influencing gene expression, which in turn can control the stress response. In particular, genetic factors can moderate the sensitivities of specific types of neural cells or circuits mediating the imprinting of the environment on different biological systems. In this current review, we wish to analyze systematic reviews and recent experimental research on the physio-pathological mechanisms that underline stress-related responses. In particular, we analyze the relationship between genetic and epigenetic factors in the stress response.

The impact of a 21-day ultra-endurance ride on the heart in young, adult and older adult recreational cyclists

BACKGROUND

This study assessed the acute effect of 21 days of challenging exercise on heart structure and function in recreationally active people across a range of age categories.

METHODS

15 recreationally active people completed a 21-day fundraising cycling ride (MADRIDE) over a distance of 3515 km. Twenty-four hour Holter electrocardiography and blood biochemistry analyses were performed before and after the MADRIDE.

RESULTS

Incidence of cardiac arrhythmia was higher after MADRIDE (OR: 5.93; 95% CI: 5.68-6.19), with increases in both ventricular arrhythmias (OR: 9.90; 95% CI: 9.27-10.57) and supraventricular arrhythmias (OR: 3.09; 95% CI: 2.91-3.29). Adults (OR: 11.45; 95% CI: 7.41-17.69) and older adults (OR: 10.42 95% CI 9.83-11.05) were approximately 10 times more likely to experience arrhythmias after the MADRIDE. Whereas, young participants experienced 18% less cardiac arrhythmias after MADRIDE (OR: 0.82; 95% CI: 0.75-0.90). Aortic valve max velocity was reduced (MD: -0.12 m/s; 95% CI: -0.19-0.05 m/s) and mitral valve deceleration time was slower (MD: -28.91 m/s; 95% CI: -50.97-6.84 m/s) after MADRIDE. Other structural and functional characteristics along with heart rate variability were not different after MADRIDE.

CONCLUSIONS

Multi-day challenging exercise increased the incidence of both supraventricular and ventricular arrhythmias in active adults and older adults. Increases in arrhythmia rates after MADRIDE occurred without changes in cardiac structure and autonomic control. Further exploration is necessary to identify the causes of exercise-induced cardiac arrhythmia in adult and older adults.

Reduced professional efficacy is associated with a blunted salivary alpha-amylase awakening response

The job demands-resources model (JD-R) has shown an ability to predict worker engagement and exhaustion, yet to our knowledge, research has not been conducted that assesses the JD-R model with physiological indicators of chronic stress and burnout. Using the JD-R model, we assessed if occupational stress and burnout were related to dysregulated cortisol and salivary alpha-amylase awakening responses (sAA-AR). Professional apprentice jockeys comprising of males (n = 14) and females (n = 18) provided morning saliva samples and completed self-report measures relating to job demands and resources, burnout, and perceived mental and physical health. Data was collected at two time points coinciding with naturally occurring 'low' and 'high' stress periods during the racing calendar. The jockeys reported good physical and mental health but had elevated levels of the burnout subtypes cynicism and exhaustion. Regression analyses suggested that those jockeys presenting with reduced professional efficacy in the high stress period produced a 'flattened' sAA-AR indicative of reduced autonomic nervous system (ANS) arousal, which has been associated with burnout. Further, decreases in professional efficacy explained the relationship between increased workplace stress and decreased ANS activity in the high stress period. Our findings suggest that assessments of psychological stress or physiology in isolation are not as useful as looking at both in combination, and extend previous findings on the sAA-AR.

Positive verbal feedback about task performance is related with adaptive physiological responses: An experimental study of the effort-reward imbalance stress model

Effort-reward imbalance in the workplace has been related with poor mental and physical health and a variety of negative organisational outcomes including increased rates of absenteeism, presentism, and job turnover, but the model has rarely been assessed using experimental designs. Female participants (N = 90) were randomly assigned to positive verbal feedback and no verbal feedback conditions. Within a simulated office environment, all participants were under time-pressure to successfully complete computer-based tasks in order to gain remuneration. Positive verbal feedback about task performance was provided to improve the aspect of 'esteem reward' (while keeping effort constant) using a mixed within-between subjects design. Psychological, behavioural (task performance), and physiological (heart rate variability, salivary alpha amylase) measures assessed the impact of the positive verbal feedback. Participants receiving the esteem manipulation did not self-report increased rewards, but performed moderately better on the task, and had more adaptive physiological reactivity in the high reward versus the standard condition. Similar to recent research our findings highlight the importance of concurrent assessments of both self-reports and physiological measures of stress, and suggest that positive verbal feedback about work performance can elicit adaptive physiological responses and may also positively influence task efficacy.

Work Stress and Altered Biomarkers: A Synthesis of Findings Based on the Effort-Reward Imbalance Model

While epidemiological studies provide statistical evidence on associations of exposures such as stressful work with elevated risks of stress-related disorders (e.g., coronary heart disease or depression), additional information on biological pathways and biomarkers underlying these associations is required. In this contribution, we summarize the current state of the art on research findings linking stressful work, in terms of an established theoretical model-effort-reward imbalance-with a broad range of biomarkers. Based on structured electronic literature search and recent available systematic reviews, our synthesis of findings indicates that associations of work stress with heart rate variability, altered blood lipids, and risk of metabolic syndrome are rather consistent and robust. Significant relationships with blood pressure, heart rate, altered immune function and inflammation, cortisol release, and haemostatic biomarkers were also observed, but due to conflicting findings additional data will be needed to reach a firm conclusion. This narrative review of empirical evidence supports the argument that the biomarkers under study can act as mediators of epidemiologically established associations of work stress, as measured by effort-reward imbalance, with incident stress-related disorders.