OXYGENATION OF THE LEFT AND THE RIGHT PREFRONTAL CORTEX IN A SIMPLE TASK OF EQUAL TIME INTERVAL

Abstract

The purpose of this study was to clarify the synchronization function of external and spontaneous rhythm and exercise in the left prefrontal cortex (Left-PFC) and the right prefrontal cortex (Right-PFC) in humans. This study examined whether there is functional difference in rhythm movement synchronization in Left-PFC and Right-PFC, or whether the synchronism with exercise differs depending on rhythm such as external rhythm and spontaneous rhythm. Subjects performed a finger tapping exercise with the right index finger with seven rhythms which consisted of six external rhythms (1 Hz to 6 Hz) and spontaneous rhythm (2.4 ± 0.3 Hz). During synchronization of rhythm and exercise, the increased amount of oxygenated hemoglobin (Oxy-Hb) in Right-PFC showed a significant increase in all rhythms (p < 0.01). The amount of Oxy-Hb in Left-PFC also showed a significant increase (p < 0.05) in all rhythms. The Oxy-Hb increase in Right-PFC was significantly higher (p < 0.01) than the Oxy-Hb increase in Left-PFC in all rhythms. Therefore, it is suggested that regardless of the difference between external and/or spontaneous rhythm, Right-PFC plays a major role with respect to the synchronization function of rhythm and movement.