A Study on Neuronal Ensemble Network Properties during Acceleration of Arm Reaching Movements

Abstract

For execution of complicate movements, coordinated plan of muscle movement is necessary. This implies that involvement of high order brain function is expected in initiation stages of movement rather than in later stages. Several studies of the graph theory have shown that the higher order brain area forms efficient network characterized by the high clustering coefficient and lower mean path length. However, no study has compared network properties of motor cortical areas between initial and later movement stages. In this study, we have investigated neuronal connectivity varying with acceleration or deceleration of reaching movements. Analyses based on the graph theory revealed that the node degree increased and the shortest path length decreased when hand movement accelerated, and vice versa. Our results imply that a neuronal network of the primary motor area forms a more efficient network for the initiation of movements.