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PloS One 2021Mental fatigue is a common problem associated with neurological disorders. Until now, there has not been a method to assess mental fatigue on a continuous scale....
Mental fatigue is a common problem associated with neurological disorders. Until now, there has not been a method to assess mental fatigue on a continuous scale. Camera-based eye-typing is commonly used for communication by people with severe neurological disorders. We designed a working memory-based eye-typing experiment with 18 healthy participants, and obtained eye-tracking and typing performance data in addition to their subjective scores on perceived effort for every sentence typed and mental fatigue, to create a model of mental fatigue for eye-typing. The features of the model were the eye-based blink frequency, eye height and baseline-related pupil diameter. We predicted subjective ratings of mental fatigue on a six-point Likert scale, using random forest regression, with 22% lower mean absolute error than using simulations. When additionally including task difficulty (i.e. the difficulty of the sentences typed) as a feature, the variance explained by the model increased by 9%. This indicates that task difficulty plays an important role in modelling mental fatigue. The results demonstrate the feasibility of objective and non-intrusive measurement of fatigue on a continuous scale.
Topics: Adult; Blinking; Computer Simulation; Eye-Tracking Technology; Female; Humans; Machine Learning; Male; Memory, Short-Term; Mental Fatigue; Models, Statistical; Pupil; Task Performance and Analysis
PubMed: 33617541
DOI: 10.1371/journal.pone.0246739 -
PeerJ 2023Mental fatigue has shown to be one of the root causes of decreased productivity and overall cognitive performance, by decreasing an individual's ability to inhibit... (Review)
Review
Mental fatigue has shown to be one of the root causes of decreased productivity and overall cognitive performance, by decreasing an individual's ability to inhibit responses, process information and concentrate. The effects of mental fatigue have led to occupational errors and motorway accidents. Early detection of mental fatigue can prevent the escalation of symptoms that may lead to chronic fatigue syndrome and other disorders. To date, in clinical settings, the assessment of mental fatigue and stress is done through self-reported questionnaires. The validity of these questionnaires is questionable, as they are highly subjective measurement tools and are not immune to response biases. This review examines the wider presence of mental fatigue in the general population and critically compares its various detection techniques (., self-reporting questionnaires, heart rate variability, salivary cortisol levels, electroencephalogram, and saccadic eye movements). The ability of these detection tools to assess inhibition responses (which are sensitive enough to be manifested in a fatigue state) is specifically evaluated for a reliable marker in identifying mentally fatigued individuals. In laboratory settings, antisaccade tasks have been long used to assess inhibitory control and this technique can potentially serve as the most promising assessment tool to objectively detect mental fatigue. However, more studies need to be conducted in the future to validate and correlate this assessment with other existing measures of mental fatigue detection. This review is intended for, but not limited to, mental health professionals, digital health scientists, vision researchers, and behavioral scientists.
Topics: Humans; Electroencephalography; Fatigue Syndrome, Chronic; Health Personnel; Heart Rate; Mental Fatigue
PubMed: 37637168
DOI: 10.7717/peerj.15744 -
The Permanente Journal Dec 2020
Topics: Burnout, Professional; Burnout, Psychological; Child; Child Abuse; Compassion Fatigue; Humans
PubMed: 33482966
DOI: 10.7812/TPP/20.011.1 -
PloS One 2022Intermittent fasting (IF) is an alternating pattern of restricting eating. This study evaluated mental and physical fatigue secondary to IF (daily 18-hour fast,...
Intermittent fasting (IF) is an alternating pattern of restricting eating. This study evaluated mental and physical fatigue secondary to IF (daily 18-hour fast, 7-days-a-week) in the high-fat diet (HFD)-induced male obese Sprague Dawley rats. Fifty-four rats were randomly assigned to a HFD (n = 28) or a standard diet (SD; n = 26). After six weeks, the HFD rats were divided into one of four groups: obese HFD ad libitum (OB-HFD-AL), obese HFD-IF (OB-HFD-IF), obese SD-AL (OB-SD-AL), and obese SD-IF (OB-SD-IF). Similarly, non-obese controls were grouped into HFD-AL (C-HFD-AL), non-obese HFD-IF (C-HFD-IF), non-obese SD-AL (C-SD-AL), and non-obese SD-IF (C-SD-IF). After 2 weeks of IF, mental and physical fatigue were measured using open field (OF) and novel object recognition (NOR) tests. Rats on IF gained weight at a slower pace (p<0.05) and had lower glucose levels (p<0.01) compared to the AL group. In non-obese rats, ketone levels were higher in the IF-HFD group than IF-SD (p<0.05) and AL-SD (p<0.01) animals. Obese rats exhibited elevated blood ketone levels in IF-SD conditions versus AL-SD rats (p<0.01). AL-HFD rats had higher ketone levels than AL-SD animals in both obese and non-obese groups (p<0.05). In conclusion, rats with higher blood ketone levels, whether they were on IF or AL, traveled a greater distance during OF suggesting a lack of physical fatigue. There was no significant difference between IF and AL during NOR indicating a lack of mental fatigue. Thus, IF results in reduced body weight and blood glucose levels but does not induce physical or mental fatigue.
Topics: Rats; Male; Animals; Fasting; Rats, Sprague-Dawley; Obesity; Diet, High-Fat; Ketones; Mental Fatigue
PubMed: 36322540
DOI: 10.1371/journal.pone.0275684 -
Scientific Reports Jun 2022Mental fatigue is a common phenomenon in modern people, especially after a long period of mental work. Individuals frequently have to make critical decisions when in a...
Mental fatigue is a common phenomenon in modern people, especially after a long period of mental work. Individuals frequently have to make critical decisions when in a mentally fatigued state. As an important and complex cognitive function, risk decision-making might be influenced by mental fatigue, which is consequent with increased distraction and poor information processing. However, how mental fatigue shapes individuals' decision-making remains relatively unclear. The purpose of this study was to examine the effect of mental fatigue on risk decision-making performance and risk-preference in a simple gambling task, using both behavioral methods and event-related potential techniques. Forty young adults were divided into a mental fatigue group and a no-fatigue group and participated in the experiments. Results showed that individuals with mental fatigue tended to be more risk-averse than those without fatigue when facing risk options. The P300 amplitudes were smaller and FRN amplitudes were larger in the mental fatigue group than in the no-fatigue group. These findings provide insight into a relationship between mental fatigue and risk decision-making, from the perspective of the neurological mechanism.
Topics: Decision Making; Electroencephalography; Evoked Potentials; Feedback; Gambling; Humans; Mental Fatigue; Young Adult
PubMed: 35739292
DOI: 10.1038/s41598-022-14682-0 -
International Journal of Sports... Feb 2022
Topics: Humans; Mental Fatigue; Sports
PubMed: 34942596
DOI: 10.1123/ijspp.2021-0524 -
Physiological Reports Jul 2021Obesity, often caused by a diet high in calories and low physical activity, may induce physical fatigue, as experienced via decreased locomotor activity and mental...
Obesity, often caused by a diet high in calories and low physical activity, may induce physical fatigue, as experienced via decreased locomotor activity and mental fatigue such as impaired cognition. This study aims to evaluate glucose and ketone levels secondary to high-fat diet (HFD) exposure and signs of physical and mental fatigue. Fifty-four 7-week-old male Sprague Dawley rats (Rattus norvegicus) were assigned to either an HFD (n = 28) or a standard diet (SD; n = 26) for a 6-week period during which body weight, blood glucose, and ketones were measured twice per week. An open field (OF) paradigm was used to measure locomotor activity, while novel object recognition (NOR) test was used as an indicator of cognition. Animals in the HFD group weighed more than SD rats (8.4 g; p < 0.05) starting at Day 11, blood glucose levels were higher in the HFD group versus SD rats (3.9 mg/dl; p < 0.05) beginning in Week 5, and ketones were lower for the HFD versus the SD group throughout the study (0.34 mmol/L on average; p < 0.05). Although there was no significant difference in locomotor activity between the HFD and SD groups (p = 0.12), regardless of diet, higher ketone levels were associated with increased NOR time and ratio between the familiar and novel objects (p < 0.01). Thus, this study provides evidence that an increased level of ketones is associated with greater cognitive performance and a lesser probability of experiencing mental fatigue.
Topics: Animals; Blood Glucose; Dietary Fats; Ketones; Male; Mental Fatigue; Obesity; Open Field Test; Rats; Rats, Sprague-Dawley
PubMed: 34197701
DOI: 10.14814/phy2.14930 -
Medicine and Science in Sports and... Oct 2023Recent studies have questioned previous empirical evidence that mental fatigue negatively impacts physical performance. The purpose of this study was to investigate the... (Randomized Controlled Trial)
Randomized Controlled Trial
INTRODUCTION
Recent studies have questioned previous empirical evidence that mental fatigue negatively impacts physical performance. The purpose of this study was to investigate the critical role of individual differences in mental fatigue susceptibility by analyzing the neurophysiological and physical responses to an individualized mental fatigue task.
METHODS
In a preregistered ( https://osf.io/xc8nr/ ), randomized, within-participant design experiment, 22 recreational athletes completed a time to failure test at 80% of their peak power output under mental fatigue (individual mental effort) or control (low mental effort). Before and after the cognitive tasks, subjective feeling of mental fatigue, neuromuscular function of the knee extensors, and corticospinal excitability were measured. Sequential Bayesian analysis until it reached strong evidence in favor of the alternative hypothesis (BF 10 > 6) or the null hypothesis (BF 10 < 1/6) were conducted.
RESULTS
The individualized mental effort task resulted in a higher subjective feeling of mental fatigue in the mental fatigue condition (0.50 (95% confidence interval (CI), 0.39-0.62)) arbitrary units compared with control (0.19 (95% CI, 0.06-0.339)) arbitrary unit. However, exercise performance was similar in both conditions (control: 410 (95% CI, 357-463) s vs mental fatigue: 422 (95% CI, 367-477) s, BF 10 = 0.15). Likewise, mental fatigue did not impair knee extensor maximal force-generating capacity (BF 10 = 0.928) and did not change the extent of fatigability or its origin after the cycling exercise.
CONCLUSIONS
There is no evidence that mental fatigue adversely affects neuromuscular function or physical exercise; even if mental fatigue is individualized, computerized tasks seem not to affect physical performance.
Topics: Humans; Bayes Theorem; Exercise; Knee; Mental Fatigue; Muscle Fatigue
PubMed: 37227196
DOI: 10.1249/MSS.0000000000003221 -
European Thyroid Journal Jul 2023Mental fatigue, depression, anxiety, and cognitive complaints are common in Graves' disease (GD). Our aims were to assess the relationship between these variables in...
OBJECTIVE
Mental fatigue, depression, anxiety, and cognitive complaints are common in Graves' disease (GD). Our aims were to assess the relationship between these variables in patients with GD during both hyperthyroidism and a long stable euthyroidism.
METHODS
A prospective longitudinal case-control study where 65 premenopausal women diagnosed with GD and 65 matched controls were assessed twice with 15 months in between. The first visit for patients was in overt hyperthyroidism and the second after treatment.
RESULTS
During the hyperthyroid phase, mental fatigue, depression, and anxiety were significantly increased for GD patients compared to controls (all P < 0.001). Among GD patients, 89% reported mental fatigue and among controls 14%. No difference in cognitive tests was found. After 15 months, significant improvements for GD patients after treatment were found for the items of mental fatigue, depression, and anxiety (all P < 0.001), but these were unchanged in controls. GD patients reported residual mental fatigue (38%), 23% without depression, and 15% mental fatigue combined with depression. Self-reported cognitive complaints were pronounced while cognitive tests did not reveal any deficiencies.
CONCLUSION
Mental fatigue and emotional distress are common in the hyperthyroid phase. These improve with treatment but are still more common in GD patients after 15 months of therapy than in controls. The residual mental fatigue is shown to be a phenomenon distinct from depression in this study. This indicates the importance of assessing mental fatigue in GD patients and underlines the need for rehabilitation and healthcare support as fatigue will have consequences for work ability.
Topics: Humans; Female; Case-Control Studies; Prospective Studies; Depression; Graves Disease; Hyperthyroidism; Cognition; Mental Fatigue
PubMed: 37224080
DOI: 10.1530/ETJ-23-0040 -
Biological Psychology Oct 2023To investigate the effects of sustained mental activity on perceptions of mental fatigue, cognitive performance, and autonomic response in patients with clinical burnout...
OBJECTIVE
To investigate the effects of sustained mental activity on perceptions of mental fatigue, cognitive performance, and autonomic response in patients with clinical burnout as compared to a healthy control group.
METHODS
Patients with clinical burnout (n = 30) and healthy control participants (n = 30) completed a 3-hour test session, in which they were administered a set of cognitive tests before and after an effortful cognitive task with concurrent sound exposure. Perceptions of mental fatigue and task demands (mental effort and concentration difficulties) were assessed repeatedly over the course of the test session. Heart rate variability was recorded to index autonomic response.
RESULTS
In comparison with controls, perceived mental fatigue increased earlier in the session for the clinical burnout group and did not recover following a short rest period. Throughout the session, patients rated the tasks as more demanding and showed less improvement on measures of attention and processing speed, inhibition and working memory. While autonomic responses were initially comparable, there was a unique decrease in high-frequency heart rate variability in the clinical burnout group after extended testing and exposure.
CONCLUSION
Patients with clinical burnout are affected differently than healthy controls by sustained mental activity, as reflected by ratings of perceived mental fatigue, aspects of cognitive performance and autonomic response. Further investigation into the role of autonomic regulation in relation to cognitive symptoms in clinical burnout is warranted.
Topics: Humans; Attention; Burnout, Professional; Memory, Short-Term; Mental Fatigue; Cognition
PubMed: 37598882
DOI: 10.1016/j.biopsycho.2023.108661