Prefrontal Cortex Activity Predicts Mental Fatigue in Young and Elderly Men During a 2 h “Go/NoGo” Task

Background: Although the effects of mental fatigue on cognitive–motor function and psychological state in young adults are well-documented, its effects in the elderly are not completely understood. The aim of this study was to estimate the effect of prolonged cognitive load on the indicators of psychological, cognitive, and motor functions.Methods: Fifteen young and 15 elderly men were asked to perform a 2 h “Go/NoGo” task. Psychological state (mood and motivation), cognitive (prefrontal cortex activity and cognitive performance), and motor (motor cortex excitability and grip strength) functions were measured before and after the task. During the 2 h task, both groups had a significantly similar increase in the number of “Incorrect NoGo” errors. Only in young men reaction time (RT) of “Incorrect NoGo” and intraindividual variability of RT of “Incorrect NoGo” significantly increased during task. After the task, handgrip strength decreased for the young men, whereas latency of motor evoked potentials prolonged both groups. Nevertheless, both groups indicated that they felt fatigue after the 2 h task; we observed that mental demand increased, whereas intrinsic motivation and mood decreased only in young men. Prolonged task decreased the switching/rest ratio of oxygenated hemoglobin for the young and the elderly men; however, greater for elderly than young men. Interestingly, the more the prefrontal cortex was activated before the 2 h task during the switching task, the fewer of “Incorrect NoGo” errors made by the young men and the greater the number of errors made by the elderly men.Conclusion: Because of the greater mental load and (possibly) greater activation of prefrontal cortex during the 2 h “Go/NoGo” task, there was greater mental and neuromuscular performance fatigue in young men than in elderly men

Cold stress induced sex-specific physiological responses

It has been suggested that one of the factors that affects response to thermal stress is sex. Women experience a faster core cooling rate than men during cold water immersion, however it is not clear if faster core cooling would induce differences at neuroendocrine response, motor and cognitive performance between men and women. Furthermore, it was established that when core temperature was above 36˚C there were no differences in physiological adjustments strategies to cold stress in men and women, however it is not clear if more extreme core cooling induces differences in responses between men and women. Thus, the aim of the research was to identify if there were any sex-specific differences in neuroendocrine response, physiological adjustments to cold stress strategies, cognitive performance, and motor performance due to whole body immersion at cold water-induced stress. The present study indicated that despite the similar level of cold stress in men and women, men exhibited greater neuroendocrine response of the hypothalamic-pituitary-adrenal (cortisol) axis and sympathetic-adrenomedulary (epinephrine) axis, greater perturbations in cognitive function, decrease in brief maximal voluntary contraction (MVC) and sustained 2-min MVC fatigability. Besides, physiological adjustments to cold stress also differed; women were more reliant on insulative response, and men were more reliant on metabolic response, particularly shivering. Thus, whole body cooling-induced sex-specific differences in physiological responses

Changes in gait after severe traumatic brain injury during post-acute rehabilitation

Research object: gait dynamic after severe traumatic brain injury during post-acute rebailitation. Traumatic brain injury (TBI) is one of the major health problems throughout the world, which undergo more than 2 million people every year (Preikšaitis ir Ročka, 2007). In recent years particular attention increased on gait after TBI. Changes in gait after TBI are very important for evaluation, clinical reasoning and for intervention programs (Williams et al., 2009). Most studies analyze walking function during acute phase (William et al., 2007), but there is lack of information during post-acute period. The aim of the research was to determine gait changes during post-acute TBI rehabilitation. Research goals: 1. To observe spatiotemporal and kinematic gait changes. 2. To observe kinetic gait changes. 3. To observe muscles electrical activity amplitude changes. 4. To observe legs reaction time, movement speed and accuracy changes. Male (21 years old) participated in the research after 2 years severe TBI. Studies show that subjects with chronic and stable motor dysfunctions improve only during specialized and intensive programs (Kunkel et al., 1999; Fasoli et al., 2003). Our participant undergone 5 weeks intensive rehabilitation program composed of 15 physiotherapy, 12 motor control and 10 yoga procedures. Physiotherapy was composed of stretching, coordination, balance and weight-bearing exercises. During motor control participant performed „accuracy“ task which helps to improve legs reaction time, movement speed and accuracy. Yoga was performed to built core stability, train flexibility and diminish muscle tone. Gait changes were observed during 3D gait analysis. Force plate was placed in the middle of walkway. Electromyographic and DPA-1 dynamic movement parameters analysis was also performed. Research hypothesis: intensive rehabilitation improves gait changes after severe TBI during post-acute period. After research several conclusions were made: 1. After rehabilitation shortened stance and swing phase’s time, lengthened step, increased velocity and cadence, changed lower extremities joint angles and center of mass amplitude (p < 0.05). 2. After rehabilitation improved bilateral weight-bearing during gait (p < 0.05). Initial contact force was stronger compared to push-off (p < 0.05). 3. After rehabilitation reduced maximal electrical amplitude of soleus muscles and rectus femoris during stance phase (p < 0.05). 4. After rehabilitation shortened legs reaction time and improved movement accuracy (p < 0.05), but no changes were observed during maximal speed

Cold stress induced sex-specific physiological responses

It has been suggested that one of the factors that affects response to thermal stress is sex. Women experience a faster core cooling rate than men during cold water immersion, however it is not clear if faster core cooling would induce differences at neuroendocrine response, motor and cognitive performance between men and women. Furthermore, it was established that when core temperature was above 36˚C there were no differences in physiological adjustments strategies to cold stress in men and women, however it is not clear if more extreme core cooling induces differences in responses between men and women. Thus, the aim of the research was to identify if there were any sex-specific differences in neuroendocrine response, physiological adjustments to cold stress strategies, cognitive performance, and motor performance due to whole body immersion at cold water-induced stress. The present study indicated that despite the similar level of cold stress in men and women, men exhibited greater neuroendocrine response of the hypothalamic-pituitary-adrenal (cortisol) axis and sympathetic-adrenomedulary (epinephrine) axis, greater perturbations in cognitive function, decrease in brief maximal voluntary contraction (MVC) and sustained 2-min MVC fatigability. Besides, physiological adjustments to cold stress also differed; women were more reliant on insulative response, and men were more reliant on metabolic response, particularly shivering. Thus, whole body cooling-induced sex-specific differences in physiological responses

A single bout of aerobic exercise impact to consolidation of bilateral movements in older adults.

Background. Aging is associated with a decline in motor coordination and learning efficiency. A single bout of exercise is used to improve learning of unilateral movements in older adults; however, the effect on learning of bilateral move-ments remains unclear.Aim. To determine the effect of a single bout of aerobic exercise on learning of bilateral movements in older adults.Methods. The study included 20 older adults and they were assigned to a control (n = 10; age: 64.5 ± 3.1 years) or experimental (n = 10; age: 63.6 ± 2.1 years) group. Participants in the experimental group performed a single 20-min-ute bout of moderate-intensity (50-70 %) aerobic exercise. Participants in the control group were asked to rest for 20 minutes. Changes in the learning of asymmetric and symmetric bilateral movements and motor consolidation 7 days after learning were evaluated using a Purdue Pegboard Test. Participants were asked to perform symmetrical and asymmetrical movements with both arms. Learning motivation was assessed immediately after learning using a Visual Analogue Scale.Results.Aerobic exercise improved motor consolidation (p < 0.05), whereas bilateral motor learning remained un-changed. Meanwhile, in the control group, the motor skill consolidation after a week did not change compared to the baseline value. Learning motivation did not differ between groups.Conclusions. A single 20-minute bout of moderate-intensity aerobic exercise can be used as an effective method to improve the consolidation of bilateral asymmetric and symmetric movements in long-term memory in older adults. ų abiem rankomis, įtvirtinimą ilgalaikėje atmintyje. Raktažodžiai: motorinė atmintis, motorinis įgūdis, pratimas, senjorai

The effects of the Nirvana Fitness exercise programme on perceived stress and cognition

Background. Mind and body exercise programmes, such as Tai Chi, Yoga and Pilates, can be successfully applied for stress reduction and cognitive function enhancement, however Nirvana Fitness training effects on perceived stress and cognition remain equivocal. The aim. To determine the effects of Nirvana Fitness training on perceived stress and cognition. Methods. The study included 20 women. They were randomly assigned to a control (n=10) or experimental (n=10) group. Participants in the experimental group participated in the Nirvana Fitness exercise programme, which consisted of a 50-minute class twice a week for 8 weeks. Participants in the control group were asked to maintain their daily routines. Changes in perceived stress and cognitive performance were evaluated. Results. The Nirvana Fitness exercise programme significantly decreased (p<0.05) perceived stress and improved (p<0.05) inhibitory control and cognitive flexibility, whereas spatial and working memory remained unchanged. Conclusion. The Nirvana Fitness programme can be used as an effective method to decrease stress and improve attention in women

Effect of different kinesiotaping techniques on nonspecific chronic low back pain.

Background. Kinesiological taping (KinT) is proposed as one of the techniques that can alleviate back pain. However, no studies have been conducted to demonstrate the most effective kinesiology taping technique for women with chronic non-specific low back pain. Aim. To determine the effects of star-shaped, “H-shaped”, and placebo kinesiology taping methods on non-specific chronic back pain, trunk mobility, static endurance of trunk muscles, and functional status in women with non-specific low back pain. Methods. Fifteen women aged 18-36 years, experiencing chronic, non-specific back pain, participated in the study. Three different taping methods were chosen: H-shaped, star-shaped, and placebo taping. The lower back of each subject was taped using all three kinesiology taping (KinT) techniques with a one-week break between different taping cycles. Subjects’ back pain, torso mobility, back muscle static endurance, and functional status were assessed using the Roland-Morris questionnaire. Results. Participants’ baseline assessments did not differ before applying different KinT techniques. Back pain intensity significantly reduced (p<0.05), and mobility and endurance of back extensor muscles increased (p<0.05) with star and H-shaped kinesio tape, but the effect of the techniques at 24 hours did not differ from each other after tape removal. Although there was no difference between taping methods after 24 hours, H-shaped taping had a greater effect than Z-shaped taping on mobility after 48 hours of taping (p<0.05). Meanwhile, functional disability decreased with all three taping methods (p<0.05) but did not differ between different taping methods. Conclusions. Star-and H-shaped KinT techniques had short-term significant positive effects on chronic non-specific back pain, lumbar mobility, static endurance of the trunk muscles, and functional status of subjects. Placebo (sham) KinT technique only reduced subjectively-assessed functional disability

Sex-related differences in attention and memory

Background and objectives: The sex differences and similarities in cognitive abilities is a continuing topic of major interest. Besides, the influences of trends over time and possible effects of sex steroid and assessment time on cognition have expanded the necessity to reevaluate differences between men and women. Therefore, the aim of this study was to compare cognitive performance between men and women in a strongly controlled experiment. Materials and methods: In total, 28 men and 25 women were investigated. Variables of body temperature and heart rate were assessed. A cognitive test battery was used to assess attention (visual search, unpredictable task switching as well as complex visual search and predictable task switching tests) and memory (forced visual memory, forward digit span and free recall test). Results: The differences in heart rate and body temperatures between men and women were not significant. There were no differences in the mean values of attention and memory abilities between men and women. Coefficients of variation of unpredictable task switching response and forward digit span were lower (P < 0.05) in men. Coefficients of variation positively correlated (P < 0.05) with attention task incorrect response and negatively correlated (P < 0.05) with correct answers in the memory task. Conclusions: Current study showed no sex differences in the mean values of cognition, whereas higher intra-individual variability of short-term memory and attention switching was identified in women, indicating that their performance was lower on these cognitive abilities

Exploring the effect of prolonged fasting on kynurenine pathway metabolites and stress markers in healthy male individuals /

BACKGROUND/OBJECTIVES: Prolonged fasting triggers a stress response within the human body. Our objective was to investigate the impact of prolonged fasting, in conjunction with stress, on kynurenine pathway metabolites. SUBJECTS/METHODS: Healthy males were divided into fasting group (zero-calorie-restriction) for 6 days (FAST, n = 14), and control group (CON, n = 10). Blood and saliva samples were collected at baseline, Day 2, Day 4, Day 6 during fasting period, and 1 week after resuming regular diet. Plasma levels of kynurenine pathway metabolites were measured using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Plasma and salivary samples were analyzed for stress markers. RESULTS: A pronounced activation of the kynurenine pathway in individuals on FAST trial was revealed. Concentrations of picolinic acid (PIC), kynurenic acid (KYNA) and 3-hydroxykynurenine (3-HK) were significantly increased, with peak levels observed on Day 6 (P < 0.0001). Conversely, concentrations of tryptophan (TRP) and quinolinic acid (QUIN) decreased (P < 0.0001), while kynurenine (KYN) and nicotinamide (NAM) levels remained stable. Cortisol and noradrenaline concentrations remained unchanged. However, adrenaline levels significantly increased on Day 4 within FAST compared to CON (P = 0.005). Notably, all deviations in kynurenine pathway metabolite levels returned to baseline values upon resuming regular diet following the 6-day fasting regimen, even when weight and BMI parameters were not restored. CONCLUSIONS: Extended fasting over 6 days induces the kynurenine pathway and has minimal effects on stress markers. Restoration of metabolite concentrations upon regular feeding implies rapid adaptation of the kynurenine pathway synthetic enzymes to maintain homeostasis when faced with perturbations