ABSTRACT
We investigated the relationship between daily physical activity level and response inhibition control aspect of cognitive function in older adults using event-related potentials. Twenty-eight Japanese older adults (70.6 ± 3.8 years) participated in the present study. Daily physical activity (PA) was measured using an accelerometer, including step count and the intensity of PA. Participants were divided on the basis of their step count into “Higher PA group” (more than 10,000 steps/day, n = 14) and “Lower PA group”(less than 10,000 steps/day, n = 14). Cognitive function was evaluated by performance, NoGo-N2, and NoGo-P3 while they performed a Go/NoGo task. The results indicated that the Higher PA group exhibited shorter reaction time on Go trials, relative to the Lower PA group. NoGo-P3 amplitude was larger in the Higher PA group compared to the Lower PA group, but NoGo-P3 latency did not differ between groups. PA was positively correlated with NoGo-P3 amplitude. NoGo-N2 component was not related to PA. Thus, PA was more sensitive to monitoring of the outcome of response inhibition rather than pre-motor inhibition in Go/NoGo task. These findings suggest that daily PA is associated with preservation of age-related declines in response inhibition control.
ABSTRACT
The interactive effects of exercise intensity and physical activity level on the brain and cognition of young adults were investigated using the electromyographic reaction time (EMG-RT), the P3, and the NoGo P3, as well as the contingent negative variation (CNV) of event-related brain potentials. Participants (n＝26 : 24.0 ± 0.7 years) were divided on the basis of their regular physical activity level into active and inactive groups. Then, they performed a Go/NoGo reaction time task in the no exercise, control condition ; as well as after light, moderate, and hard cycling exercises. Results indicated that increases in P3 and NoGo P3 amplitude following moderate exercise were larger in the inactive group, suggesting that inactive individuals were more sensitive to exercise intensity than active individuals. Active individuals might be better able to sustain their attention during the Go/NoGo reaction time task, despite the exercise intensity. These findings are suggestive of a differential effect of exercise intensity on cognitive function that might be dependent on the level of regular physical activity. The effects of exercise intensity on EMG-RTs were observed across groups. However, the P3 latency was not affected by exercise intensity. These contradictory results are possible related to the nature of the cognitive task, such as its difficulty. Moreover, increases in CNV amplitudes following moderate exercise were larger than in other exercise conditions across groups, suggesting that motor preparation process is also facilitated by moderate, acute exercise. These findings provide additional evidence for the beneficial effects of acute aerobic exercise on the brain and cognition of young adults.