Neurobiological Basis of Brain Blood Oxygenation Responses Correlated with Cognitive Stroop Task Performance Before and After an Acute Bout of Aerobic Exercise

Abstract

Cardiovascular activities may increase the brain blood flow improving neural activities leading to improved cognition. Consequently, the effects of an acute bout of moderate intensity aerobic exercise on cortical brain blood oxygenation and its correlation with cognitive color-word Stroop task performance were tested. The Stroop tasks were congruent (color matches word) and incongruent (color does not match word). Prefrontal (PFC) and motor cortex (MC) blood flow was recorded by fNIRS (functional Near-Infrared Spectroscopy) while the human subjects performed the Stroop tasks before and after 30 minutes of exercise or equivalent time of rest (controlling for practice effect of repeating the Stroop task multiple times). It was predicted that PFC blood flow increase after exercise will correlate with increased Stroop interference and decreased cognitive flexibility after an acute bout of aerobic exercise at 70% of maximal Heart Rate (HR). We observed that Stroop interference in aerobic exercise and practice alone (rest) were not significantly (p>0.6) different indicating that exercise did not improve cognition above the learning effect. Increase in blood flow (both neurovascular and neurometabolic coupling) in previously deactivated PFC channels was positively correlated (p<0.05) to increased Stroop interference (worse cognitive speed and accuracy) after an acute bout of aerobic exercise.HighlightsDoes moderate intensity aerobic exercise improve cognition?Does prefrontal cortex oxygenation correlate with cognition changes after exercise?