Physical activity affects cognitive function in view of prefrontal cortex activation

Abstract

Previous studies have revealed that physical activity can affect brain function and cognitive decline. Additionally, we confirmed that brain activation in the prefrontal cortex (PFC) during a cognitive task was correlated with cognitive function. Based on these findings, we hypothesized that brain activation also affects cognitive function, which increases due to stimulation from physical activity. The purpose of this study was to verify causal relationships between physical activity, PFC activation, and cognitive function using the statistical method of path analyses in a multi-model approach. Forty-six healthy volunteers (10 males, mean age: 76.1, standard deviation: 6.8) participated in this study. Informed consent was obtained from all participants prior to enrollment. This study was approved by the Ethics Committee of Seirei Christopher University (approval No. 10067). We assessed physical activity via participants' self-reports, determined PFC activation during a dual task using near-infrared spectroscopy, and measured cognitive function with the Trail-Making Test Part B. To determine the causal relationship between physical activity, PFC activation, and cognitive function, path analyses were conducted using AMOS 16 structural equation modeling. The structural equation model was a good fit (root mean square error of approximation = 0.001). Several significant direct paths were identified: (1) from physical activity to PFC activation (b = 0.37), and (2) from PFC activation to cognitive function (b = 0.32). This study statistically revealed the causal relationships between physical activity, PFC activation, and cognitive function. Path analyses indicated that physical activity affected cognitive function via PFC activation.