Mental Fatigue

This randomized, double-blind, placebo-controlled, parallel-group trial will evaluate the effects of 14 days of taurine-caffeine supplementation with or without phosphatidylserine on neurocognitive fatigue resistance, visual search efficiency, and football-specific tactical decision-making in professional male football players. Sixty-two male outfield football players from two professional clubs will be randomized to placebo, taurine plus caffeine, or taurine plus caffeine plus phosphatidylserine. Laboratory and field-based outcomes will be assessed at baseline and after the supplementation period.

As people grow older, it is common to experience a drop in physical stamina and memory functions. This can make recovering from daily physical and mental fatigue more difficult, which directly impacts an individual's independent daily life and overall quality of life. "Cognitive reserve" is a term that describes the brain's built-in resilience. Built over a lifetime through education, work, and social activities, a higher cognitive reserve acts like a buffer, helping the brain adapt to stress and aging. While research shows that a high cognitive reserve protects against conditions like dementia, we still do not fully understand how it helps older adults bounce back from normal, everyday physical and mental exhaustion. The goal of this study is to investigate how cognitive reserve levels influence how individuals aged 65 and older perceive their recovery after experiencing physical and mental fatigue. What the Study Involves The researchers will evaluate participants aged 65 and older to measure their baseline cognitive reserve levels. The study will look closely at how these levels affect the participants': Ability to cope with daily physical and mental fatigue. Need for rest and rest patterns. Time and ability to return to normal daily activities. Overall perception of their mental and physical recovery. Expected Outcome By understanding this relationship, the study aims to fill a gap in medical literature and help healthcare providers design better, more personalized rehabilitation and lifestyle support programs to improve the quality of life for older adults.

This observational, prospective, within-subject study will examine how the volume and timing of physiotherapy and psychology classes and exams at LUDES Institute influence mental fatigue, sleepiness, motivation, executive function, and physical performance in university students. Approximately 30 students aged 18 years or older will complete repeated assessments at baseline (no formal academic activities), during a regular theoretical class, and, when feasible, during an exam session. At each time point, participants will undergo non-invasive measurements including self-reported mental fatigue (visual analogue scale), sleepiness (Karolinska Sleepiness Scale), motivation (Motivational States Scale), cognitive performance (Encephalapp Stroop task), and handgrip strength and endurance with perceived exertion ratings, alongside sleep diaries and wrist actigraphy. The primary endpoint is the pre-to post-session change in mental fatigue and cognitive performance, with secondary endpoints capturing sleep and circadian metrics, physical performance, motivation, and exam grades. Mixed-effects models will be used to test how class/exam duration, time of day, sleep quantity and quality, and chronotype relate to psychobiological responses, with the goal of informing evidence-based scheduling and workload policies in health-profession education.

This randomized crossover study investigates the effects of mental fatigue on postural control and spinal reflex excitability in healthy physically active adults aged 18-35 years. Participants will complete two experimental conditions: a mentally fatiguing Stroop task and a control condition involving passive documentary watching, separated by at least 48 hours. Postural control will be assessed using force plate measures of center of pressure displacement during bipedal and unipedal stance, with and without concurrent cognitive dual-tasking. In parallel, spinal reflex excitability will be evaluated using H-reflex recordings from the triceps surae muscles across sitting and standing postures. The primary aim is to determine whether mental fatigue increases postural sway, particularly in more challenging balance conditions such as single-leg stance. The secondary aim is to examine whether mental fatigue alters the normal modulation of spinal reflex excitability across progressively demanding postural tasks. Additional biomechanical and neuromuscular measures, including EMG activity and hip kinematics, will be recorded to provide insight into underlying control mechanisms. The study will include approximately 26 participants, with each serving as their own control. Data will contribute to understanding how cognitive fatigue influences balance control and spinal-level neuromuscular regulation.

Mental fatigue (MF) is known to impair cognitive performance and may negatively affect physical performance. While its effects on lower-extremity functional performance have been investigated, little is known about the influence of MF on upper-extremity physical performance tests commonly used in sports and rehabilitation settings. This randomized crossover study will investigate the effects of experimentally induced mental fatigue on upper-extremity physical performance in 16 healthy physically active adults. Participants will complete both a mental fatigue condition, involving a prolonged Stroop task, and a control condition consisting of watching an emotionally neutral documentary. Before and after each condition, participants will perform the Upper Quarter Y Balance Test, Reactive Upper Quarter Y Balance Test, Closed Kinetic Chain Upper Extremity Stability Test, and Seated Single-Arm Shot Put Test. Subjective mental fatigue, cognitive performance, motivation, and perceived exertion will also be assessed. The findings will improve understanding of whether mental fatigue influences upper-extremity physical performance test outcomes and may assist clinicians and researchers in interpreting these assessments in sports medicine and rehabilitation contexts.

This study aims to understand how different types of fatigue affect balance and reaction time, proprioception, and fine motor in healthy young adults. Fatigue is a common experience in daily life and can arise from physical activity or prolonged mental effort. The study seeks to determine whether fatigue of the upper body, lower body, or mental fatigue from cognitively demanding tasks can negatively affect balance and reaction time, proprioception, and fine motor abilities. To examine this, participants will undergo controlled fatigue protocols designed to tire specific parts of the body or the mind. the Upper body fatigue will be induced through repeated maximal push-up sets performed until the participant can no longer maintain proper form. Lower body fatigue will be created through repeated maximal 1-minute squat jump sets, with participants touching a low box to ensure standardized depth and proper movement. Mental fatigue will be induced using a 20-minute computer-based cognitive task that alternates between the 2-back working memory task and the numerical Stroop task. These tasks are designed to require continuous attention, mental effort, and inhibitory control. Each type of fatigue will be induced independently, and participants' performance will be measured before and after each fatigue protocol. Following fatigue induction, participants will complete a series of tests designed to assess balance and reaction time, proprioception, and fine motor abilities. This includes both static and dynamic postural tasks, as well as reaction time and proprioceptive accuracy assessments. By evaluating these measures before and after fatigue, the study will determine how different forms of physical and mental fatigue impact postural stability, sensory processing, and precise motor control. The study addresses the question: "Do upper body fatigue, lower body fatigue, or mental fatigue reduce balance and reaction time, proprioception, and fine motor performance in healthy young adults?" The hypothesis is that each form of fatigue upper body, lower body, or mental-will meaningfully impair balance and reaction time, proprioception, and fine motor performance compared to non-fatigued conditions.

This study is designed as an open label, single arm, decentralized clinical study in which first responders will receive transcutaneous auricular neurostimulation (tAN), which targets the auricular branch of the vagus nerve (ABVN) via the mastoid and the auriculotemporal nerve (ATN) anterior to the tragus. Participants will be enrolled in the study over the course of eight weeks (56 days). Participants will respond to daily and weekly questionnaires regarding mood, stress, sleep, energy/fatigue, and burnout. Each week, participants will complete consolidated online questionnaires (intended to last no longer than 15 minutes) comprised of the Perceived Stress Short-Form (PSS-4), Well-Being Index (WHO-5), Mini-Z Burnout (5-item), PROMS Sleep Disturbance (PROMIS-SD), GAD-7 (every 2 weeks), and Perceived Stress (PSS-10; monthly). The PSS-10 will replace the PSS-4 on Days 0, 28, and 56. No tAN treatment will be delivered during the Baseline Period (days between Study Introduction and Day 0). Participants will complete the weekly set of questionnaires ("Weekly Questionnaires") on Day 0. Participants will be recommended to complete the daily set of questionnaires ("Daily Questionnaires ") on the other days of the Baseline Period. On Days 1 - 28, participants will self-administer one session of one to two hours of tAN therapy each day. Participants will be recommended to complete the daily tAN session post-shift prior to sleep. Weekly Questionnaires will be completed by participants on Study Days 0, 7, 14, 21, 28, 35, 42, 49, and 56. Participants will be recommended to complete Daily Questionnaires on all other study days, up to Day 28. Daily Questionnaires will not be required to be completed by participants. Daily tAN sessions and Daily Questionnaires will cease after Day 28. Participants will complete a Study Satisfaction Questionnaire with the Weekly Questionnaires on Day 56. Following Day 56, participants will schedule a Study Exit Interview with the Research Coordinator.

Mental fatigue (MF) negatively affects both cognitive and physical performance, increasing the risk of errors in high-stakes environments such as sports and surgery. Traditional methods to assess MF rely on subjective self-report scales, which are prone to bias, or on complex brain measurements (e.g. EEG) that are impractical outside laboratory settings. This study aims to develop a real-time, objective monitoring method for MF using wearable physiological sensors. The study will recruit healthy, trained runners (18-35 years old) who will complete both an MF-inducing cognitive task (Stroop test) and a control condition (watching a documentary) in a randomized, counterbalanced, crossover design. Heart rate variability, respiration rate, and pupil metrics will be continuously recorded using wearable devices. Machine learning models will be used to predict MF-level as well as the effect of MF on physical performance (5-km time trial on a treadmill) using the physiological data as input.

The proposed project will evaluate the synergistic effects of a nutritional formulation, 'Think Tank' on cognitive performance following exposure to a psychological and physical stressor. Adopting a double-blind repeated measures cross-over design, middle-aged females (40-60 years) will be recruited to take part in a two-stage research study that will examine whether the formulation enhances cognitive performance and subjective well-being following the challenge of a stressor, compared to placebo. Cognitive assessments will examine the impact of the nutritional formulation on working memory, sustained attention, cognitive flexibility and inhibitory control. The study will also assess physiological (heart rate, blood pressure and cortisol) and subjective (well-being, anxiety, positive and negative mood, stress) markers of stress reactivity. The study will also explore levels sleep quality, mental and physical fatigue, effort, productivity, and perceived impact of the intervention.

Mental fatigue occurs in many diseases and the reasons are mostly unknown. The investigators hypothesize that remaining mental fatigue after restored hyperthyroidism in Graves' disease is an autoimmune complication. The aim of this study is to explore immunological markers possibly associated with mental fatigue in Graves' disease, which the investigators plan to validate in another study (ImmunoGraves wp 2). Using a cross-sectional study design, mental fatigue is scored using a questionnaire to find 60 patients with and 60 without mental fatigue 15-60 months after diagnosis of Graves disease. The patients and 60 thyroid healthy controls without mental fatigue are assessed for thyroid hormones, quality of life, anxiety and depression, self-evaluated stress, coping strategies, eye symptoms and background variables. SciLifeLab in Stockholm, the national facility for autoimmune profiling, has pre-set large arrays including 42000 human proteins. Serum and cerebrospinal fluid will be separately pooled and analysed for a subgroup of patients with or without mental fatigue and for a subgroup of the control group. Proteins that preferably bind to antibodies in sera and/or cerebrospinal fluid from Graves' patients with mental fatigue in comparison to non-mental fatigue patients, will be screened against the Human Protein Atlas and the Allen brain map to identify those proteins that are expressed in the brain. Antibodies at higher concentration in the mental fatigue pools compared to the group without mental fatigue will be selected for further analyses on an individual level in the whole cohort together with antibodies targeting g-protein coupled receptors, thyroid autoantibodies, cytokines and biomarkers indicating organic and structural nerve damage.

This study aims to evaluate the effects of music intervention on golf-specific skill performance under mental fatigue. It is a randomised, controlled, double-blind design. The study consists of three main phases: familiarisation with the experimental procedure, baseline testing, and the formal experiment. During the formal experiment, participants will be randomly assigned to one of the following three groups: (MF-Mu Group) Participants undergo a mental fatigue induction task followed by a music intervention; (MF-nMu Group) Participants undergo a mental fatigue induction task but do not receive a music intervention; (CON Group) Participants neither undergo a mental fatigue induction task nor receive a music intervention. The total intervention duration is 45 minutes, consisting of 30 minutes of mental fatigue induction and 15 minutes of music intervention. In conditions where mental fatigue induction or music intervention is not conducted, participants will remain in the same experimental environment and rest quietly for the same duration to control for external confounding factors and ensure experimental consistency. Immediately after the intervention, participants will complete golf skill testing, with the testing site located within a 2 minutes walking distance from the intervention area. Performance outcomes include driving performance, iron shot performance, chipping performance, and putting performance.

Mental fatigue occurs in many diseases and the reasons are mostly unknown. The investigators hypothesize that remaining mental fatigue after restored euthyroidism in Graves' disease is an autoimmune complication. This is a confirmatory study of the biomarkers from ImmunoGraves WP1 in which immunological markers with possible association with mental fatigue in Graves' disease are explored. In ImmunoGraves WP2, 310 patients with Graves' disease are assessed for symptoms of mental fatigue, quality of life, anxiety and depression, self-evaluated stress, coping strategies, personality traits, eye symptoms and background variables. Participants are examined in hyperthyroidism at inclusion, within three weeks from diagnosis, and in euthyroidism after 15 months. Serum and cerebrospinal fluid (in a subsample of participants) is collected at both visits and will be evaluated for the immunological markers identified in WP1 as well as for thyroid hormones, thyroid autoantibodies and biomarkers indicating organic and structural nerve damage. Significant predictors for mental fatigue will be identified by logistic regression. To assess functional changes in the brain, magnetoencephalography will be performed in a subset of patients and in healthy controls at inclusion and after 15 to 18 months. Combined with magneto resonance imaging (MRI), magnetoencephalography gives information on neuronal activation during attention testing.