According to a study published in NeuroImage, childhood exercise prior to entering junior high school predicts better response inhibition in later life. This association is moderated by changes in neuronal activity – including increased cortical thickness and efficiency, as well as strengthened inter-hemispheric connectivity.
Inhibitory control is a component of cognitive control, referring to the ability to control attention, behavior, as well as thoughts and emotions in order to override strong internal predispositions, irrelevant stimuli, and external distractions. Response inhibition in particular has an essential role in overriding impulsive reactions for the purpose of improving health behaviors. Exercise interventions have been shown to alter brain structure and functions in regions that are implicated in cognitive control; these neural systems fully develop by age 16. Thus, it could be the case that during childhood and adolescence, exercise could have a more substantial influence on response inhibition and its implicated neural systems, compared to other periods in life.
A total of 214 participants were recruited from suburban Tokyo and its surrounding areas. Participants completed a questionnaire regarding their exercise participation during childhood and adulthood, including the starting age, period, frequency, and duration of all exercise. This data was obtained and categorized in accordance with developmental stages (i.e., childhood, early adolescence, later adolescent, and adulthood). Participants also completed a questionnaire examining current physical activity (e.g., household and yard work, sedentary activity).
Response inhibition was examined using the Go/No-go task, whereby participants are prompted to respond to frequent stimuli with a probability of 80%, and to withhold responding to rare stimuli with a probability of 20%. Information pertaining to potential confounding variables were also collected (e.g., education, number of siblings). MRI data was acquired at the Tamagawa University Brain Science Institute.
Toru Ishihara and colleagues found that childhood exercise was positively associated with response inhibition in later life, with this association being moderated by decreased structural and functional connectivity in the frontoparietal, cingulo-opercular and default mode networks, as well as increased inter-hemispheric structural networks. This association was also moderated by greater cortical thickness and lesser dendritic arborization and density in these networks.
Importantly, the association between childhood exercise and later-life response inhibition was unique to early childhood exercise (less than 12 years old), and was not observed for individuals who participated in exercise after age 12. The researchers argue that these findings suggest exercise in early life could contribute to improved cognitive function and brain health in the long-term.
The researchers note a few limitations. Given the study was conducted using a historical cohort design, causal inferences cannot be drawn from the observed positive relationship between childhood exercise and later-life inhibitory control. They suggest an alternative explanation may be that individuals with better response inhibition happened to engage in exercise more regularly.
Another limitation is that exercise participation data was obtained using self-report questionnaires, as such, accuracy was largely dependent on participants’ ability to recall this information accurately. Lastly, the researchers are unable to disentangle the extent to which the observed benefits of childhood exercise were associated with the physical activity, as opposed to other features of structured programs, such as routines and cognitive challenges.
The study, “Childhood exercise predicts response inhibition in later life via changes in brain connectivity and structure”, was authored by Toru Ishihara, Atsushi Miyazaki, Hiroki Tanaka, Takayuki Fujii, Muneyoshi Takahashi, Kuniyuki Nishina, Kei Kanari, Haruto Takagishi, and Tetsuya Matsuda.
