Fatigue influence on inhibitory control: Cardiovascular and performance findings elucidate the role of restraint intensity

Origins and consequences of cognitive fatigue

Everybody knows intuitively what mental fatigue is. However, we poorly understand why fatigue emerges with time spent on demanding cognitive work and how such 'cognitive fatigue' impacts neural processing and behavioral guidance. Here, we review experimental investigations that induced cognitive fatigue and recorded its potential markers, including self-report, behavioral performance, economic choice, physiological and neural activity. We then review theoretical models of cognitive fatigue, classically divided into biological and motivational accounts. To explain key observations and reconcile debated theories, we finally propose a conceptual model (dubbed MetaMotiF), in which cognitive fatigue would emerge for biological reasons and yet affect motivational processes that regulate the behavior. More precisely, fatigue would arise from metabolic alterations in cognitive control brain regions, following their excessive mobilization. In turn, these metabolic alterations would increase the cost of cognitive control, which would shift decisions towards actions that require little effort and yield immediate rewards.

Approaches to inducing mental fatigue: A systematic review and meta-analysis of (neuro)physiologic indices

Mental fatigue is a transient psychophysiological state characterized by impaired cognition and behavior across a range of dynamic contexts. Despite increasing interest in this phenomenon, its (neuro)physiologic representations remain unclear. This systematic review aimed to quantify the range of (neuro)physiologic outcomes and methodologies used to investigate mental fatigue in laboratory-based settings. Across the 72 studies meeting our inclusion criteria, we identified 30 unique physiologic, four visual outcomes, and the application of several neuroimaging techniques investigating neuronal function. Mental fatigue increased heart rate, systolic and diastolic blood pressure, mean arterial pressure, low frequency, and root mean square of successive differences (RMSSD), and reduced standard deviation of normal-to-normal intervals (SDNN) (all P ≤ 0.04) when compared with controls. Applying electroencephalography to investigate delta, theta, and alpha bandwidths may provide useful insights into this phenomenon, and functional near-infra-red spectroscopy to right-lateralized frontoparietal regions would be helpful to investigate cortical activity change in response to mental fatigue. More data are needed across a range of methodological contexts in order to further determine the (neuro)physiological manifestations of mental fatigue. However, this review provides direction to researchers and will assist them in navigating and considering the range of options available.

Affective Influences on the Intensity of Mental Effort: 25 Years of Programmatic Research

This article highlights the systematic impact of experienced and implicit affect on the intensity of mental effort. The key argument is that both consciously experienced affect and implicitly activated affect knowledge can influence responses in the cardiovascular system reflecting effort intensity by informing individuals about task demand-the key variable determining resource mobilization. According to the motivational intensity theory, effort rises with experienced demand as long as success is possible and the necessary effort is justified. Twenty-five years of programmatic research have provided clear evidence that both consciously experienced affect and implicitly activated affect knowledge systematically influence the intensity of effort. Importantly, affect's impact on effort is moderated by task context variables, like objective task difficulty, incentive, and other general boundary conditions.

Boosting arousal and cognitive performance through alternating posture: Insights from a multi-method laboratory study

This study investigated the role of arousal and effort costs in the cognitive benefits of alternating between sitting and standing postures using a sit-stand desk, while measuring executive functions, self-reports, physiology, and neural activity in a 2-h laboratory session aimed to induce mental fatigue. Two sessions were conducted with a one-week gap, during which participants alternated between sitting and standing postures each 20-min block in one session and remained seated in the other. In each block, inhibition, switching, and updating were assessed. We examined effects of time-on-task, acute (local) effects of standing versus sitting posture, and cumulative (global) effects of a standing posture that generalize to the subsequent block in which participants sit. Results (N = 43) confirmed that time-on-task increased mental fatigue and decreased arousal. Standing (versus sitting) led to acute increases in arousal levels, including self-reports, alpha oscillations, and cardiac responses. Standing also decreased physiological and perceived effort costs. Standing enhanced processing speed in the flanker task, attributable to shortened nondecision time and speeded evidence accumulation processes. No significant effects were observed on higher-level executive functions. Alternating postures also increased heart rate variability cumulatively over time. Exploratory mediation analyses indicated that the positive impact of acute posture on enhanced drift rate was mediated by self-reported arousal, whereas decreased nondecision time was mediated by reductions in alpha power. In conclusion, alternating between sitting and standing postures can enhance arousal, decrease effort costs, and improve specific cognitive and physiological outcomes.

Vision-based estimation of fatigue and engagement in cognitive training sessions

Computerized cognitive training (CCT) is a scalable, well-tolerated intervention that has promise for slowing cognitive decline. The effectiveness of CCT is often affected by a lack of effective engagement. Mental fatigue is a the primary factor for compromising effective engagement in CCT, particularly in older adults at risk for dementia. There is a need for scalable, automated measures that can constantly monitor and reliably detect mental fatigue during CCT. Here, we develop and validate a novel Recurrent Video Transformer (RVT) method for monitoring real-time mental fatigue in older adults with mild cognitive impairment using their video-recorded facial gestures during CCT. The RVT model achieved the highest balanced accuracy (79.58%) and precision (0.82) compared to the prior models for binary and multi-class classification of mental fatigue. We also validated our model by significantly relating to reaction time across CCT tasks (Waldχ2=5.16,p=0.023). By leveraging dynamic temporal information, the RVT model demonstrates the potential to accurately measure real-time mental fatigue, laying the foundation for future CCT research aiming to enhance effective engagement by timely prevention of mental fatigue.

Cognitive conflict does not always mean high effort: Task difficulty's moderating effect on cardiac response

This article presents an experiment (N = 127 university students) testing whether the previously found impact of conflict primes on effort-related cardiac response is moderated by objective task difficulty. Recently, it has been shown that primed cognitive conflict increases cardiac pre-ejection period (PEP) reactivity-an index of effort intensity-during the performance of relatively easy tasks. This effect could be attributed to conflict-related negative affect. Consequently, as it has been shown for other types of negative affect, we expected conflict primes' effect to be task-context dependent and thus to be moderated by objective task difficulty. In a between-persons design, we manipulated conflict via embedded pictures of conflict-related vs. non-conflict-related Stroop items in a memory task. We expected primed conflict to increase effort in a relatively easy version of the task but to lead to disengagement when task difficulty was objectively high. PEP reactivity corroborated our predictions. Rather than always increasing effort, cognitive conflict's effect on resource mobilization was context-dependent and resulted in weak responses in a difficult task.

Predictors of self-regulation fatigue patterns in patients before total knee arthroplasty: A cross-sectional study

BACKGROUND

Patients with total knee arthroplasty encounter stressful events that consume their coping resources, resulting in self-control fatigue. Few studies have focused on this phenomenon.

AIM

To identify subgroups of patients before total knee arthroplasty according to the heterogeneous patterns of self-regulation fatigue and to analyse the predictors of subtypes.

METHODS

A total of 210 patients awaiting total knee arthroplasty were enrolled. Data of demographic characteristics, clinical characteristics, psychological and social factors were collected. Latent profile analysis was employed to define the subgroups. Predictors of patterns were identified using multinomial logistic regression.

RESULTS

Three latent classes were identified: the low, medium, and high self-regulation fatigue classes. For the high self-regulation fatigue class, lower levels of hope, social support, self-efficacy and education were major predictors.

CONCLUSION

These predictors of patients with different levels of self-regulation fatigue provide evidence for the identification of vulnerable populations and lay a foundation for targeted interventions.

A Novel Physical Fatigue Assessment Method Utilizing Heart Rate Variability and Pulse Arrival Time towards Personalized Feedback with Wearable Sensors

This paper proposes a novel method for physical fatigue assessment that can be applied in wearable systems, by utilizing a set of real-time measurable cardiovascular parameters. Daylength measurements, including a morning test set, physical exercise during the day, and an afternoon test set were conducted on 16 healthy subjects (8 female and 8 male). To analyze cardiovascular parameters for physical fatigue assessment, electrocardiography, pulse wave and blood pressure were measured during the test sets. The fatigue assessment questionnaire score, reaction time, countermovement jump height and hand grip strength were also measured and used as reference parameters. This study demonstrates that (i) the compiled test battery can selectively assess the rested vs. physically-fatigued states; (ii) the obtained linear support-vector machine, trained using the heart rate variability based parameter (F-score 0.842, accuracy 0.813) and pulse arrival time based parameter (F-score 0.875, accuracy 0.875) shows a promising ability to classify between the physically mildly fatigued and significantly fatigued states. Despite the somewhat limited study group size, the results of the study are unique and provide a significant advancement on the existing physical fatigue assessment methods towards a personalized and continuous real-time fatigue monitoring system with wearable sensors.