To what extent do our free-living physical activity (PA) levels impact our cognition? For example, if we engage in more intense PA from one week to the next, does this have a corresponding influence on cognitive performance? Across three studies, young adults completed a validated self-report questionnaire (the International Physical Activity Questionnaire, or IPAQ) assessing their involvement in PA at low, moderate, and vigorous intensities over the past week, as well as computer-based measures of executive control and attentional function. In Experiment 1 we found no significant effect of PA intensity on any of our measures of executive control. In a pair of follow-up control studies we examined whether these null findings could be attributed to testing fatigue and task complexity (Experiment 2), or low cognitive demands of the task (Experiment 3). Despite simplifying the task, reducing testing time, and increasing the cognitive load of the task, we still found no significant impact of weekly PA intensity on our measures of executive control. Taken together, our results show that self-reported PA over the past week, at any intensity level, does not appear to have a substantive impact on executive control.

Physical activity (PA) promotes neurogenesis and has neuroprotective effects on the brain, bolstering the structural and functional resources necessary for improved cognitive functioning. Intraindividual variability (IIV) in cognitive performance is linked to neuropsychological structure and functional ability. Despite evidence of the neurogenerative and neuroprotective effects of PA, limited investigation into the link between PA and IIV has been conducted. Across three studies we investigate the effect of PA on IIV in reaction time (RT) on three modified Flanker Tasks. The International PA Questionnaire was used to evaluate PA while the Attention Network Test (ANT) and two additional modified Flanker Tasks were used to assess executive control and attentional performance. RT coefficients of variation (RTCV) were calculated for each participant by dividing the standard deviation by the mean RT for each stimuli condition. Analysis revealed that basic RT was not associated with PA nor was PA predictive of IIV on the modified Flanker Tasks. However, three consistent findings emerged from analysis of the ANT. First, RTCV and moderate PA were positively related, such that more self-reported moderate PA was associated with greater IIV. Conversely, RTCV and vigorous PA were negatively related. Finally, when controlling for the effects of PA on IIV in young adults, variability decreases as age increases. In sum, PA is predictive of IIV on attentional and executive control tasks in young adults, though only at particular intensities and on certain tasks, indicating that task type and cognitive load are important determinants of the relationship between PA and cognitive performance. These findings are consistent with prior literature that suggests that the role of PA in young adults is reliant on specific interventions and measures in order to detect effects more readily found in adolescent and aging populations.

In the original article, there was an error. The descriptive definition for the coefficient of variation was incorrectly provided. In the original manuscript the definition was given as the mean reaction time divided by the standard deviation. This was an error as the coefficient of variation was calculated as the standard deviation divided by the mean.A correction has been made to the Materials and Methods section, subsection Coefficient of Variation, paragraph 1:"The RT coefficient of variation (RTCV) was selected as the primary measure of individual variability and was the dependent variable in data analysis. The RTCV is calculated by dividing the standard deviation of a participant's RT by their mean RT for each measure. For example, in Experiment 3, the standard deviation of the RT for all of one participant's incompatiblecongruent trials would be divided by the mean RT of the corresponding trials. The resulting value is a standardized score that can be compared across measures. A RTCV was calculated for each participant for each cognitive measurement."The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

No abstract