Application of a NIRS Neuroimaging Method to Elucidate Neural Mechanisms of Exercise-cognition Interaction

PURPOSE There is growing attention on a neuroimaging method called near-infrared spectroscopy (NIRS), which enables the monitoring of task-related regional hemodynamic responses in the brain. The basic principles and appropriate experimental conditions should be explained to eliminate potent contaminations caused by exercise itself and to summarize well-organized recent studies focusing on the interaction between exercise and cognition before applying this noninvasive neuroimaging method to various studies in the field of Exercise Science. METHODS A comprehensive search of PubMed, Web of Science, and Google Scholar was performed to obtain recent studies examining the effects of exercise (or physical activity) on the executive functions localized in the prefrontal cortex by adopting the NIRS system. RESULTS NIRS system enables exercise scientists to measure regional brain activity to investigate the effects of exercise on cognition and its neural substrates. Numerous studies have revealed that higher physical activity (or fitness) levels are related to better performance with increased prefrontal cortical activation during a task. Moreover, several longitudinal exercise intervention studies have demonstrated improved executive performance without increased task-related brain activation, particularly among older adults. CONCLUSIONS NIRS neuroimaging studies support the notion that exercise has beneficial effects on executive function, with exercise-elicited functional changes in the prefrontal cortex

ヒトの実行機能は低強度運動で高まるか : fNIRSを用いたニューロイメージング研究

筑波大学 (University of Tsukuba)201

Effects of Limiting the Number of Ball Touches on Physical and Technical Performance of the Junior Football Players during Small-sided Game

PURPOSE We aimed to examine the effects of limiting the number of ball touches on the physical and technical performances of junior football players during small-sided games (SSGs), which are widely used to improve football-specific physical and technical performances. METHODS Nineteen middle-school football players participated in the study and took a pretest for their physical and technical skills to be evaluated before the main experiment. During the SSG, to balance teams according to the players’ levels of physical fitness and skill, we selected players with the highest to lowest total scores and organized them in an ABBA order. Ten players who obtained the highest scores participated in the SSG once a week for 5 weeks under the limitation of a certain number of ball touches (one, two, three, four, or free touches). Players could only play with a set number of touches. Each SSG consisted of 4-min sets with 4-min breaks after each set on a pitch with a goal. RESULTS As the number of possible touches increased, the total distance and average speed of the players increased, and the distance ratio covered by running (over 13 km/h), but not walking or jogging, also increased. Regarding technical factors, as the number of touches a player could make increased, the number of passes decreased, whereas the rates of dribbles and defensive tackles increased. CONCLUSIONS As the number of ball touches increased during the SSG, the young players covered a greater distance with a higher speed, unlike professional players, and the frequency of skills mostly used, such as passing and dribbling during the SSG, showed different results

Aerobic fitness associates with mnemonic discrimination as a mediator of physical activity effects: evidence for memory flexibility in young adults

A physically active lifestyle has beneficial effects on hippocampal memory function. A potential mechanism for this effect is exercise-enhanced hippocampal plasticity, particularly in the dentate gyrus (DG). Within hippocampal memory formation, the DG plays a crucial role in pattern separation, which is the ability to discriminate among similar experiences. Computational models propose a theoretical hypothesis that enhanced DG-mediated pattern separation leads to “memory flexibility”–a selective improvement in the ability to overcome moderate levels of mnemonic interference. Thus, in the current cross-sectional study of healthy young adults, we tested the working hypothesis that aerobic fitness, as a physiological indicator of endurance capacity associated with physical activity, is strongly associated with mnemonic discrimination at moderate interference levels. When divided the sample (n = 75) based on a median split of aerobic fitness, the higher fitness group had better discrimination performance for moderate interference levels compared to the lower fitness group, namely, exhibited memory flexibility. Moreover, aerobic fitness levels were positively associated with discrimination performance for moderate interference levels, as a mediator of physical activity effects. This evidence suggests that aerobic fitness levels are associated with hippocampal DG-related memory, which is consistent with literature showing positive effect of physical exercise on hippocampal memory

Aerobic fitness associates with mnemonic discrimination as a mediator of physical activity effects: evidence for memory flexibility in young adults.

A physically active lifestyle has beneficial effects on hippocampal memory function. A potential mechanism for this effect is exercise-enhanced hippocampal plasticity, particularly in the dentate gyrus (DG). Within hippocampal memory formation, the DG plays a crucial role in pattern separation, which is the ability to discriminate among similar experiences. Computational models propose a theoretical hypothesis that enhanced DG-mediated pattern separation leads to "memory flexibility"-a selective improvement in the ability to overcome moderate levels of mnemonic interference. Thus, in the current cross-sectional study of healthy young adults, we tested the working hypothesis that aerobic fitness, as a physiological indicator of endurance capacity associated with physical activity, is strongly associated with mnemonic discrimination at moderate interference levels. When divided the sample (n = 75) based on a median split of aerobic fitness, the higher fitness group had better discrimination performance for moderate interference levels compared to the lower fitness group, namely, exhibited memory flexibility. Moreover, aerobic fitness levels were positively associated with discrimination performance for moderate interference levels, as a mediator of physical activity effects. This evidence suggests that aerobic fitness levels are associated with hippocampal DG-related memory, which is consistent with literature showing positive effect of physical exercise on hippocampal memory

Aerobic fitness associates with mnemonic discrimination as a mediator of physical activity effects: evidence for memory flexibility in young adults.

A physically active lifestyle has beneficial effects on hippocampal memory function. A potential mechanism for this effect is exercise-enhanced hippocampal plasticity, particularly in the dentate gyrus (DG). Within hippocampal memory formation, the DG plays a crucial role in pattern separation, which is the ability to discriminate among similar experiences. Computational models propose a theoretical hypothesis that enhanced DG-mediated pattern separation leads to "memory flexibility"-a selective improvement in the ability to overcome moderate levels of mnemonic interference. Thus, in the current cross-sectional study of healthy young adults, we tested the working hypothesis that aerobic fitness, as a physiological indicator of endurance capacity associated with physical activity, is strongly associated with mnemonic discrimination at moderate interference levels. When divided the sample (n = 75) based on a median split of aerobic fitness, the higher fitness group had better discrimination performance for moderate interference levels compared to the lower fitness group, namely, exhibited memory flexibility. Moreover, aerobic fitness levels were positively associated with discrimination performance for moderate interference levels, as a mediator of physical activity effects. This evidence suggests that aerobic fitness levels are associated with hippocampal DG-related memory, which is consistent with literature showing positive effect of physical exercise on hippocampal memory

Mild exercise improves executive function with increasing neural efficiency in the prefrontal cortex of older adults.

This study examined whether a 3-month mild-exercise intervention could improve executive function in healthy middle-aged and older adults in a randomized control trial. Ultimately, a total of 81 middle-aged and older adults were randomly assigned to either an exercise group or a control group. The exercise group received 3 months of mild cycle exercise intervention (3 sessions/week, 30-50 min/session). The control group was asked to behave as usual for the intervention period. Before and after the intervention, participants did color-word matching Stroop tasks (CWST), and Stroop interference (SI)-related reaction time (RT) was assessed as an indicator of executive function. During the CWST, prefrontal activation was monitored using functional near-infrared spectroscopy (fNIRS). SI-related oxy-Hb changes and SI-related neural efficiency (NE) scores were assessed to examine the underlying neural mechanism of the exercise intervention. Although the mild-exercise intervention significantly decreased SI-related RT, there were no significant effects of exercise intervention on SI-related oxy-Hb changes or SI-related NE scores in prefrontal subregions. Lastly, changes in the effects of mild exercise on NE with advancing age were examined. The 81 participants were divided into two subgroups (younger-aged subgroup [YA], older-aged subgroup [OA], based on median age [68 years.]). Interestingly, SI-related RT significantly decreased, and SI-related NE scores in all ROIs of the prefrontal cortex significantly increased only in the OA subgroup. These results reveal that a long-term intervention of very light-intensity exercise has a positive effect on executive function especially in older adults, possibly by increasing neural efficiency in the prefrontal cortex