抄録
Although it is said that daily exercise habit improves cognitive function, direct evidence on the effect remains unknown. We hypothesized whether 1) ergometer exercise with a moderate intensity could improve cognitive function, and 2) neuronal activation in the frontal cortex played a role in improving cognitive function. To test the hypotheses, we asked 18 subjects to perform a Stroop color-word test (SCWT) before and 5 min after exercise for 15 min at 0% (without exercise), 20%, 40%, and 60% of the maximum exercise. The total time and the number of errors in the SWCT were recorded as an index of cognitive function. To estimate cerebral blood flow in the frontal brain, oxygenated hemoglobin concentration (O2Hb) was continuously monitored with near-infrared spectroscopy. The total time for SCWT was not influenced by 0% and 20% exercise but shortened by 40% and 60% exercise. The number of errors was not altered by any intensity of exercise. When measuring O2Hb during 40% exercise, we found a gradual and sustained increase in O2Hb, which lasted for more than 5 min following exercise. O2Hb gradually increased in the SCWT and peaked 40-50 s after SCWT onset. Its relative increase of O2Hb by SCWT was the same before and after exercise. These results indicate that 1) dynamic exercise with a moderate intensity improves cognitive function and 2) the changes of cerebral oxygen metabolism in the frontal cortex may be in association with improved cognitive function. [J Physiol Sci. 2007;57 Suppl:S166]
