2008 Volume 6 Pages 230-237
It is well known that visual feedback of exerted force enhances muscle force during maximal voluntary contraction (MVC). Based on the previous reports on the force exertion tasks and the other tasks using the visual feedback paradigm, we hypothesized that the prefrontal cortex (PFC) is related to the enhancement of voluntary contraction force. The purpose of this study was to test the hypothesis and to identify the detail active regions in the PFC that correlates with the muscle force enhancement with visual feedback of exerted force, using near-infrared spectroscopy (NIRS). The cerebral blood flow of 11 male subjects was measured by NIRS during the MVC tasks with visual feedback of exerted torque (VFB) and without visual feedback (nVFB). As a result, both the elbow flexion torque during MVC and cerebral blood flow of the right PFC significantly increased under the VFB condition (p<0.05). In addition, the increased cerebral blood flow of the right PFC was correlated with the torque enhancement (p<0.05). The present results suggest that the right PFC is related to the increase of torque under the VFB condition. Since the PFC has a significant role in motivation, the enhancement of torque with visual feedback may be associated with such a function.
