Adaptive control during reaching movements in humans

Details

Supervisors

Crevecoeur, Frédéric ; Lefèvre, Philippe

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil biomédical

Abstract

Understanding how the Central Nervous System (CNS) manages unexpected perturbations during movement is a big challenge in motor control. We explored here the hypothesis that the CNS updates its internal model of dynamics on-line following the principles of adaptive control. We explored this hypothesis in reaching movements where velocity-dependent force fields were randomly and unexpectedly applied. We discovered that real-time corrections for perturbation improved across trials. By exploring muscle activity through surface recordings, we found that the changes in EMG activity consistent with the improved on-line control occurred on average 375 ms after the beginning of the movement. This change could not be systematically explained by the kinematics of the movement, reflecting distinct internal processings of sensory feedback. The original contribution of this manuscript is to show based on muscle recordings that the nervous system may alter its internal representation of movement dynamics within an ongoing movement, in less than ~400ms.