Mental Fatigue State Research Articles

Mental fatigue does not affect static balance under both single and dual task conditions in young adults

The ability to control balance and prevent falls while carrying out daily life activities may require a predominantly controlled (cognitive) or automatic processing depending on the balance challenge, age, or other factors. Consequently, this process may be affected by mental fatigue which has been shown to impair cognitive abilities. Controlling static balance in young adults is a relatively easy task that may proceed automatically with minimal cognitive input making it insusceptible to mental fatigue. To investigate this hypothesis, static single and dual task (while concurrently counting backward by seven) balance was assessed in 60 young adults (25.2 ± 2.4 years) before and after 45 min of Stroop task (mental fatigue condition) and watching documentary (control), presented in a randomized counterbalanced order on separate days. Moreover, because mental fatigue can occur due to task underload or overload, participants carried out two different Stroop tasks (i.e., all congruent, and mainly incongruent trials) on separate days in the mental fatigue condition. Results of the study revealed a significantly higher feeling of mental fatigue after the mental fatigue conditions compared to control (p < 0.001). Similarly, the performance on congruent Stroop trials decreases with time indicating objective mental fatigue (p < 0.01). However, there was no difference in balance or concurrent task performance under both single and dual task assessments between the three conditions (p > 0.05) indicating lack of effect of mental fatigue on static balance in this population. Therefore, future studies investigating this phenomenon in occupational or sport settings in similar population should consider using more challenging balance tasks.

Individualized Mental Fatigue Does Not Impact Neuromuscular Function and Exercise Performance.

Recent studies have questioned previous empirical evidence that mental fatigue negatively impacts physical performance. The purpose of this study is 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. In a pre-registered (https://osf.io/xc8nr/), randomized, within-participant design experiment, twenty-two 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 (BF10 > 6) or the null hypothesis (BF10 < 1/6) were conducted. The individualized mental effort task resulted in a higher subjective feeling of mental fatigue in the mental fatigue condition: 0.50 (95%CI 0.39 - 0.62) AU compared to control: 0.19 (95%CI 0.06 - 0.339) AU. However, exercise performance was similar in both conditions (control; 410 (95%CI 357 - 463) vs. mental fatigue 422 (95%CI 367 - 477) seconds, BF10 = 0.15). Likewise, mental fatigue did not impair knee extensor maximal force generating capacity (BF10 = 0.928) and did not change the extent of fatigability or its origin after the cycling exercise. 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.

Acute effects of mental recovery strategies in simulated air rifle competitions.

The present study aimed to assess the perception and change of mental and physical fatigue and to examine acute effects of mental recovery strategies in air rifle athletes across simulated competition days with two consecutive competition bouts. We conducted a randomized counterbalanced crossover study. 22 development air rifle athletes (Mage = 17.77 ± 4.0) of a regional squad participate in the study. The Short Recovery and Stress Scale (SRSS), perception of mental fatigue, physical fatigue, concentration and motivation as well as differential Ratings of Perceived Exertion (RPE) were used to assess recovery-stress states and fatigue states. During a recovery break, participants underwent two mental recovery strategies (powernap, systematic breathing) or a control condition. Total shooting scores were recorded for both competition bouts. Study results revealed a significant increase of post ratings for mental (p < .001) and physical fatigue (p < .001) for both competition bouts. The correlation coefficient between change in mental and physical fatigue for both competitions revealed a shared variance of 7.9% and 18.6%, respectively. No significant group-based acute effects of the use of mental recovery strategies on shooting performance, and psychological and perceptual measures were found. On an individual level, results illustrated statistical relevant improvements of shooting performance after powernapping or systematic breathing. Mental and physical fatigue increased and accumulated across a simulated air rifle competition and mental fatigue emerged as a separate construct from physical fatigue. The use of strategies to accelerate mental recovery on an individual level (e.g., powernap, systematic breathing) may be a first step to manage a state of mental fatigue, but further studies on mental recovery strategies in an applied setting are needed.

Mental Fatigue: The Cost of Cognitive Loading on Weight Lifting, Resistance Training, and Cycling Performance.

Mental fatigue (MF) can impair physical performance in sport. We tested the hypothesis that cognitive load alone, and intermixed with standard resistance training, would induce MF, increase rating of perceived exertion (RPE), alter perception of weight lifting and training, and impair cycling time-trial performance. This 2-part study employed a within-participant design. In part 1, after establishing leg-extension 1-repetition maximum(1RM), 16 participants lifted and briefly held weights at 20%, 40%, 60%, and 80% of 1RM. RPE and electromyography (EMG) were measured for each lift. During the testing sessions, participants completed cognitive tasks (MF condition) or watched neutral videos (control condition) for 90minutes before lifting the weights. In part 2, they completed submaximal resistance training comprising 6 weight training exercises followed by a 20-minute cycling time trial. In the MF condition, they completed cognitive tasks before and between weight training exercises. In the control condition, they watched neutral videos. Mood (Brunel Mood Scale), workload (National Aeronautics and Space Administration Task Load Index), MF-visual analogue scale (MF-VAS), RPE, psychomotor vigilance, distance cycled, power output, heart rate, and blood lactate were measured. In part 1, the cognitive task increased lift-induced RPE (P = .011), increased MF-VAS (P = .002), and altered mood (P < .001) compared with control. EMG did not differ between conditions. In part 2, the cognitive tasks increased RPE (P < .001), MF-VAS (P < .001), and mental workload (P < .001), but reduced cycling time-trial power (P = .032) and distance (P = .023) compared with control. Heart rate and blood lactate did not differ between conditions. A state of MF induced by cognitive load, alone or intermixed with physical load, increased RPE during weight lifting and training and impaired subsequent cycling performance.

Identifying mental fatigue of construction workers using EEG and deep learning

Construction workers frequently experience mental fatigue owing to the high cognitive load of their tasks in a dynamic, complex environment, diminishing their cognitive ability and mobility and necessitating monitoring to ensure safety. Traditional fatigue evaluations rely on the subjective judgment of site managers and workers; this study developed a wireless device to objectively monitor the mental fatigue of construction workers using electroencephalogram (EEG) signals. The EEG signals of 16 construction workers were recorded while they performed a continuous physical–cognitive task, and the resulting EEG time–frequency–energy data were processed by a continuous wavelet transform and convolutional neural network to identify mental fatigue states without requiring manual feature extraction. The cognitive fatigue state classifications provided by the proposed framework were shown to match the self-reported fatigue states with 88.85% accuracy. This method can therefore facilitate real-time, continuously updating fatigue identification to support safety management on construction sites.

Mental Fatigue Impairs Second Serve Accuracy in Tennis Players

ABSTRACT Purpose: The aim of this 2-week randomized, counterbalance and crossover study was to investigate the effect of acute mental fatigue (MF) on tennis serve performance and accuracy in tennis players. Methods: Ten male tennis players (18 ± 4 years, 1.80 ± 0.08 m; 71 ± 13 kg) were randomized to either the MF group (N = 5) that underwent an acute MF protocol or to a control (CON) group (N = 5). The MF condition consisted in a 30-min modified Stroop color word task performed before on-court serve speed test. A visual analogue scale (VAS) was used to assess the perceptions of MF and motivation toward the upcoming technical tests. Results: Reduction over baseline score of Stroop test was noted in accuracy (N < .001), but not in reaction time (N = .968) in the MF group. Increments in perceived workload were detected (N < .001) in MF group compared to CON. No differences for first and second serve speed from deuce and advantage side were observed. Increment of percentage of failed second serves from the deuce side (N = .043) in MF were detected. Conclusions: An acute MF protocol reduced tennis serve accuracy from deuce side in male tennis players. Players should avoid cognitive efforts before training sessions and matches to prevent negative effects of their technical performance.

Autonomic Nervous Pattern Recognition of Students’ Learning States in Real Classroom Situation

The current work applied machine learning methods to analyze students’ group and individual learning states in the real classroom environment. The purpose is to provide insights into the learning process for teachers and students, so that they can manage the learning process effectively. We extracted three couples of learning states in real classroom learning, i.e., information input/processing and retrieval/processing states, cognitive load matching and mismatching states, and mental fatigue and nonfatigue states. The recognition of the above three couples of learning states was regarded as five binary classification problems. We collected electrocardiogram (ECG) data from 45 college students during their classes of circuit analysis and calculated the peaks of two consecutive R waves (RR) interval series from the ECG data. For each binary classification problem, RR interval features and classifiers were compared to find the critical feature subsets and suitable classifiers for the recognition of learning states. The generalization accuracies of the machine learning models were in the range of 58.41%–82.35% on the validation sets independent of classifier training and feature selection. The results show that it is feasible to monitor students’ learning states through machine learning methods.

THE IMPACT OF CONSUMER FATIGUE FROM MAKING DECISION ON THE FORMATION OF BRAND LOYALTY

Purpose. The purpose of the article is the formation of theoretical, methodological and practical foundations for the implementation of marketing tools to assess the impact of consumer fatigue from making everyday decisions on brand loyalty and purchasing behaviour in stores. Methodology of research. The theoretical and methodological basis of the article was formed by the provisions of behavioural economics, neuro-marketing, and branding. The study is based on the dialectical method of learning the influence of consumer fatigue from decision-making on brand loyalty. General scientific and special methods are used within the limits of the mentioned approach, in particular: comparison – to determine the advantages and disadvantages of different groups of marketing tools; questionnaire survey – for a pilot study of the criteria for making a decision on the purchase of goods by consumers in stores; mathematical modelling – for evaluating the data obtained during the experiment and determining the tendencies of choosing the company's product or brand by consumers during fatigue; analysis and synthesis – to form a mechanism for the implementation of neuro-marketing tools by companies; induction and deduction – to interpret conclusions based on research results. Findings. The phenomenon of consumer decision fatigue resulting from repeated choice-making is explored, leading to mental exhaustion and impaired behaviour control, affecting brand loyalty. A concept is formulated for the application of neuro-marketing tools to understand consumer behaviour in retail stores, which engages all human sensory organs, including audio influence, visualization, tactile stimulation, scent influence, and taste stimulation. Pilot study of the purchasing behaviour of consumers in a state of physical or mental fatigue and without it was conducted. It has been established that closer to the evening, consumer fatigue from decision-making is observed, as during the day people may be under the influence of stressful factors, depleting emotional and cognitive resources. The factors that are important in making a decision regarding the choice of a product of a certain brand are singled out. The hypothesis regarding the influence of consumer fatigue from decision-making on the formation of brand loyalty was confirmed. Originality. The concept is formulated of using neuromarketing tools for a better understanding of consumer behavior in stores, a more detailed analysis of the decision-making process and their purchasing behavior, the formation of habits and loyalty to company brands, consumer reactions to product packaging and labeling in a state of fatigue. Practical value. The results of the pilot study will help create more effective marketing campaigns using a personalized approach to consumers and simplified communication. Key words: consumer behaviour, decision fatigue, marketing, shopping in stores, brand loyalty, neuro-marketing.

Measuring and Computing Cognitive Statuses of Construction Workers Based on Electroencephalogram: A Critical Review

Construction workers’ cognitive statuses affecting their safety and productivity are essential for successful construction management. Electroencephalogram (EEG) provides a potential objective tool for measuring and computing the cognitive status of construction workers. This study aims to answer how to adopt EEG for measuring and computing construction workers’ cognitive statuses through a critical review. The literature search and selection process included 21 eligible articles. The content analysis was then conducted from three aspects of investigated cognitive statuses, experiment design, and data analysis. The investigated cognitive statuses include vigilance, mental fatigue, mental stress, attention, mental workload, and emotional state. The experiment design is reviewed from the perspective of participant selection, device selection and electrode deployment, task design, and label selection. The data analysis involves EEG signal preprocessing, feature extraction, and cognitive status computation. Five major limitations of the existing studies have been identified, and five future research directions are proposed to address these limitations. This review provides guidance for researchers to use EEG for measuring and computing various cognitive statuses of construction workers. It also provides valuable suggestions for future research and on-site construction management.

The effects of mental fatigue on effort allocation: Modeling and estimation.

Mental fatigue is usually accompanied by drops in task performance and reduced willingness for further exertion. A value-based theoretical account may help to explain such negative effects. In this view, mental fatigue influences perceived costs and rewards of exerting effort. However, no formal mathematical framework has yet been proposed to model and quantitatively estimate the effects of mental fatigue on subjective evaluations of effort expenditure, under possibly imperfect self-perceptions of internal fatigue states. We proposed a mathematical framework to model human cognitive effort allocations, assuming mental fatigue states are partially observable with semi-Markov dynamics. We modeled effort allocation decisions as a means to the goal of maximizing cumulative subjective values over a given time horizon. We developed an estimation method to identify subjective values and the hidden dynamics of mental fatigue, which can in future work be applied to self-reports, psychophysiological indices, and behavioral outcomes associated with fatigue. The modeling and estimation method was tested using a simulated n-back task under a free-choice paradigm, with model parameters fine-tuned from past studies. The proposed approach was able to recapitulate task performance and task engagement patterns observed under mental fatigue. This work advances a reward/cost trade-off account for explaining the exertion of mental effort and suggests new avenues for both theoretically and empirically relevant understandings of how cognitive operations are affected by mental fatigue. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Feasibility study of personalized speed adaptation method based on mental state for teleoperated robots.

The teleoperated robotic system can support humans to complete tasks in high-risk, high-precision and difficult special environments. Because this kind of special working environment is easy to cause stress, high mental workload, fatigue and other mental states of the operator, which will reduce the quality of operation and even cause safety accidents, so the mental state of the people in this system has received extensive attention. However, the existence of individual differences and mental state diversity is often ignored, so that most of the existing adjustment strategy is out of a match between mental state and adaptive decision, which cannot effectively improve operational quality and safety. Therefore, a personalized speed adaptation (PSA) method based on policy gradient reinforcement learning was proposed in this paper. It can use electroencephalogram and electro-oculogram to accurately perceive the operator’s mental state, and adjust the speed of the robot individually according to the mental state of different operators, in order to perform teleoperation tasks efficiently and safely. The experimental results showed that the PSA method learns the mapping between the mental state and the robot’s speed regulation action by means of rewards and punishments, and can adjust the speed of the robot individually according to the mental state of different operators, thereby improving the operating quality of the system. And the feasibility and superiority of this method were proved. It is worth noting that the PSA method was validated on 6 real subjects rather than a simulation model. To the best of our knowledge, the PSA method is the first implementation of online reinforcement learning control of teleoperated robots involving human subjects.

Physical and Mental Fatigue Reduce Psychomotor Vigilance in Professional Football Players.

Professional football players experience both physical and mental fatigue (MF). The main aims of this randomized crossover study were to investigate the effect of MF on repeated-sprint ability (RSA) and the effects of both physical fatigue and MF on psychomotor vigilance. Seventeen male professional football players performed 10 maximal 20-m shuttle sprints interspaced by incomplete recovery (RSA test). Running speed, heart rate, brain oxygenation, and rating of perceived exertion were monitored during each sprint. The RSA test was preceded by either a 30-minute Stroop task to induce MF or by watching a documentary for 30minutes (control [CON]) in a randomized counterbalanced order. Participants performed a psychomotor vigilance test at baseline, after the cognitive task (MF or CON), and after the RSA test. Heart rate and rating of perceived exertion significantly increased, while running speed and brain oxygenation significantly decreased over the repeated sprints (P < .001) with no significant differences between conditions. Response speed during the psychomotor vigilance test significantly declined after the Stroop task but not after CON (P = .001). Response speed during the psychomotor vigilance test declined after the RSA test in both conditions (P < .001) and remained lower in the MF condition compared to CON (P = .012). MF does not reduce RSA. However, the results of this study suggest that physical fatigue and MF have negative and cumulative effects on psychomotor vigilance. Therefore, strategies to reduce both physical fatigue and MF should be implemented in professional football players.

Listening to 15 Hz Binaural Beats Enhances the Connectivity of Functional Brain Networks in the Mental Fatigue State-An EEG Study.

Introduction: It is clear that mental fatigue can have many negative impacts on individuals, such as impairing cognitive function or affecting performance. The aim of this study was to investigate the role of sound interventions in combating mental fatigue. Method: The subjects were assessed on various scales, a psychomotor vigilance task (PVT) task, and a 3 min resting-state electroencephalogram (EEG), followed by a 20 min mental fatigue–inducing task (Time Load Dual Back, TloadDback), during which subjects in different condition groups listened to either 15 Hz binaural beats, 40 Hz binaural beats, relaxing music, or a 240 Hz pure tone. After the mental fatigue–inducing task, subjects were again assessed on various scales, a PVT task, and a 3 min resting-state EEG. Results: After the fatigue-inducing task, there was no significant difference between the four groups on the scales or the PVT task performance. In TloadDback, the accuracy rate of the 40 Hz binaural beats group and the relaxing music group decreased in the middle stage of the task, while the 15 Hz binaural beats group and the 240 Hz pure tone group remained unchanged in all stages of the task. The EEG results showed that after fatigue inducement, the average path length of the 15 Hz binaural beats group decreased, and local efficiency showed an increasing tendency, indicating enhanced brain network connectivity. Meanwhile, the 240 Hz pure tone group showed enhanced functional connectivity, suggesting a state of mental fatigue in the group. Conclusions: The results of this study show that listening to 15 Hz binaural beats is a proven intervention for mental fatigue that can contribute to maintaining working memory function, enhancing brain topological structure, and alleviating the decline in brain function that occurs in a mentally fatigued state. As such, these results are of great scientific and practical value.

The effect of mental and muscle fatigue on spatial working memory

Introduction: Fatigue is a gradual and cumulative process. This mindset is related to the lack of motivation to make any effort, as well as decreased efficiency, attentiveness, and, eventually, malfunction. Aim: The present study aims to investigate how mental and muscle fatigue affects spatial working memory. Method: The research method was quasi-experimental and was performed using the pretestposttest design. The participants in this study were 20 to 30 year old male students of Shahid Beheshti University of Tehran in 2021, of whom, 14 subjects were selected by convincing method as the sample using the G-Power approach and previous investigations. The Mental Fatigue Self-Assessment Scale, Corsi Block software, Stroop software, and the Monark Bike Ergometer were utilized. In addition, the repeated measurement analysis of variance test in SPSS-23 was used to analyze the data. Results: The results indicated that mental fatigue condition had a significant effect on working memory (P=0.002); and has reduced the efficiency of working memory. But muscle fatigue conditions had no significant effect on assessing working memory, and in these conditions there was a better performance in working memory (P=0.065). Conclusion: The findings of this study emphasize the importance of mental fatigue in reducing working memory performance, even though this type of fatigue is related to cognitive and cerebral functioning. Accordingly, the findings are in line with a top-down approach, as well as cognitive perspectives such as generalized motor program theory.

Mental Fatigue Prior to Aerobic Exercise Reduces Exercise Pleasure and Negatively Affects Implicit Attitudes Toward Future Exercise.

We investigated the effects of mental fatigue (MF) on affective responses during an aerobic exercise session at moderate intensity. We submitted 12 insufficiently active adults (50% women; M age = 24.9years, SD = 3.0; M BMI = 24.3kg/m2; SD = 2.6) to two 30-minute pre-exercise conditions: an MF condition (Stroop Color-Word task) and a control condition (watching a documentary) prior to their performance of 20minutes of aerobic treadmill exercise at 40-59% of heart rate reserve. The minimum washout interval between conditions was twodays. Perceived MF and motivation to perform physical exercise were assessed before and after conditions with a visual analog scale of 100mm. We assessed participants' affective and exertion responses with the Feeling Scale, Rating of Perceived Exertion (RPE) and heart rate during every twominutes of physical exercise. Implicit attitudes toward physical exercise were assessed by the Implicit Association Test before the MF and control conditions and after the physical exercise session. The participants in the MF condition reported lower pleasure (M difference = -1.57, 95% CI = -2.64 to -0.50, d = 0.93, p = .008) and higher exertion (RPE) (M difference = 1.16, 95% CI = 0.04 to 2.27, d = 0.66, p = .043) compared to those in the control condition. Participants who experienced MF also reported a more negative implicit attitude toward physical exercise than in the control condition (β = -0.47, 95% CI= -0.73 to -0.21, d = 1.41, p < .001). While these findings should be cross-validated in subsequent research with a larger and more diverse participant sample, there appears to be value in minimizing pre-exercise mental fatigue to avoid negative MF effects on the exercisers' affective experience.

Burnout Syndrome in a Military Tertiary Hospital Staff during the COVID-19 Contingency.

(1) Background: Burnout syndrome (BOS) is defined as a psychological state of physical and mental fatigue associated with work. The COVID-19 pandemic greatly impacted the physical and mental wellbeing of health professionals. The objective of this work was to determine the impact on personnel, monitoring the frequency of BOS throughout the pandemic. (2) Methods: The Maslach Burnout Inventory (MBI) was self-applied in four periods of the pandemic according to sociodemographic and employment characteristics. In this study, all hospital personnel were included; the association of BOS with sex, age, type of participant (civilian or military), military rank and profession was analyzed. (3) Results: The frequency of BOS was 2.4% (start of the pandemic), 7.9% (peak of the first wave), 3.7% (end of the first wave) and 3.6% (peak of the third wave). Emotional exhaustion (EE) was the most affected factor, and the groups most affected were men under 30 years of age, civilians, chiefs and doctors, especially undergraduate medical doctors and specialty resident doctors, and nursing personnel were less affected. (4) Conclusions: The low BOS levels show that the containment measures and military training implemented by the hospital authorities were effective, although the chief personnel were more affected in the first wave. It is probable that this combination allowed the containment of BOS, which was not observed in civilians.

Assessment of the mental fatigue state of an operator influenced by electromagnetic noise radiation

Objectives. The problem of determining the mental fatigue of the operator, which is processing the confidential information under the influence of electromagnetic noise radiation, is solved. The relevance of the problem is associated with the need to process the confidential information by the operator located in the limited space of a mobile technical system.Methods. The methods of spectral analysis theory of the results, received in the process of experimental studies the electroencephalograms, are used.Results. The results of experimental studies were obtained based on the processing and analysis of electroencephalograms recorded in standard leads Fp1, Fp2, F3, F4, C3, C4, P3, P4, O1, O2, F7, F8, T3, T4, T5, T6. The following quantitative parameters have been analyzed: power spectral density of delta-, theta-, alpha-, beta-, gamma-rhythms under the influence of electromagnetic noise radiation.Conclusion. The presence of mental fatigue of the operator is based on a comparative analysis of the obtained results and the data described in the scientific literature related to the occurrence of chronic mental fatigue; the fatigue caused by the military performing simulation tasks; mental fatigue caused by performing an RVP test.

Mental Fatigue-Associated Decrease in Table Tennis Performance: Is There an Electrophysiological Signature?

Mental fatigue (MF) is a psychobiological state negatively impacting both cognitive and physical performance. Although recent research implies that some table tennis (TT) performance outcomes are impaired by MF, open skill sports such as TT require a more detailed overview of MF-related performance decrements. Moreover, research into MF and sport-specific psychomotor performance lacks the inclusion of brain-related measurements to identify MF mechanisms. Eleven experienced TT players participated in this randomized counterbalanced crossover trial. Participants were either required to perform an individualized Stroop task (MF condition) or watch a documentary (control condition). The primary outcomes were reaction time on a sport-specific visuomotor task and EEG activity throughout the trial. The subjective feeling of MF was significantly different between both conditions and confirmed that the MF condition induced the mentally fatigue state of participants (p < 0.001), though no behavioral indicators (i.e., decrease in performance on Stroop and flanker task) of MF. MF worsened reaction time on the visuomotor task, while other secondary measurements remained largely ambiguous. Spectral power (i.e., decreases in upper α band and θ band) was influenced by MF, while ERPs measured during the visuomotor task remained unaltered. The present study confirms that MF negatively impacts table tennis performance, specifically inhibitory stimuli during the visuomotor task. These findings also further augment our understanding of the effects of MF on human performance.

Effects of smartphone use before resistance exercise on inhibitory control, heart rate variability, and countermovement jump

Background The effect of MF induced by exposure time to social media smartphone apps on inhibitory control, heart rate variability (HRV), and high-intensity physical effort following a resistance exercise session might indicate whether strength and conditioning professionals should suggest avoiding smartphone usage before a resistance exercise session. Aim The objective of this study was to analyze the effect of mental fatigue on inhibitory control, HRV, and countermovement jump (CMJ) in trained adults after resistance exercise. Methods A total of 16 trained males (21.4 ± 3.3 years) volunteered in this study. The participants performed resistance exercises with and without mental fatigue. The Stroop Task, countermovement jump, and heart rate variability were evaluated before and after the resistance exercise. The participants used smartphones in the mental fatigue condition, whereas the participants watched TV in the control condition. Results No condition × time interaction was found for the Stroop accuracy (p = 0.87), CMJ (p = 0.68), SDNN (p = 0.15), or pNN50 (p = 0.15) in the heart rate variability. An interaction was found for Stroop response time (p = 0.01) with a higher response time for the mental fatigue condition (p = 0.01). Conclusions Mental fatigue impaired the inhibitory control performance after a resistance exercise session in trained adults.

Mental Fatigue Reduces the Benefits of Self-Controlled Feedback on Learning a Force Production Task.

This study investigated the impact of mental fatigue and self-controlled versus yoked feedback on learning a force production task. We randomly assigned 44 non-athlete male students (Mage = 21.4, SD = 1.4 years) to four groups; (a) MF&SCF = mental fatigue & self-controlled feedback, (b) MF&Y = mental fatigue & yoked, (c) NMF&SCF = no mental fatigue & self-controlled feedback, and (d) NMF&Y = no mental fatigue & yoked). SCF group participants were provided feedback whenever they requested it, while YK group participants received feedback according to a schedule created by their SCF counterparts. To induce mental fatigue, participants performed a Stroop color-word task for one hour. During the acquisition (practice) phase, participants were asked to produce a given percentage of their maximum force (20%) in 12 blocks of six trials. We recorded the participants' absolute error at the end of the acquisition phase, the immediate retention test, the first transfer test, and the second transfer test (after 24 hours and without any further mental fatigue). The acquisition phase data were analyzed in a 2 (feedback) × 2 (mental fatigue) × 12 (block) ANOVA with repeated measures on the last factor, while the retention and transfer data were analyzed in 2 (feedback) × 2 (mental fatigue) ANOVAs. We found that all four groups made significant progress during practice (p < .001), but there were no significant group differences during this phase (p>.05). There was a significant interaction effect of self-controlled feedback and mental fatigue at retention (p = .018) and transfer testing (p < .001). In the mental fatigue condition, participants in the self-controlled group had poorer learning compared to participants in the yoked group; but when not mentally fatigued, participants in the self-controlled group had better learning than those in the yoked group. These findings suggest that mental fatigue reduces typical advantages of self-controlled feedback in motor learning.