Cardinali, L. 1, 2 , Brozzoli, C. 3 , Luauté, J. . 1, 4 , Roy, A. C. 2, 5 & Farnè, A. 1, 2
1 IMPACT, Neuroscience Research Center, Lyon, France
2 Université Claude Bernard-Lyon1, Lyon, France
3 Department of Neuroscience, Brain, Body & Self Laboratory, Karolinska Institutet, Stockholm, Sweden
4 Hospices Civils de Lyon, Service de Rééducation Neurologique, Lyon, France
5 L2C2, Institut des Sciences Cognitives, Bron, France
We investigated the plasticity of the body representation for action (Body Schema, BS) by studying tool-use in a deafferented patient, C.D., with a peripheral deafferentation of the right arm. We asked C.D. to grasp an object with both her right (deafferented) or left hand and a mechanical grab. We then analysed her kinematics. We found that double peaks of acceleration and velocity characterized the kinematic of the deafferented hand. The same kinematic profile was present when the same hand was controlling the tool. Moreover, the patient showed a relatively fast process of learning in using the tool, since the kinematics evolved during the training. This pattern was not present for the left hand as there was no difference between first and last block of movements, in line with what we showed in a previous study in normal subjects, who did not show motor learning in using the same tool. Finally, in the post-training, the deafferented hand showed a normal kinematic profile that was still present 6 months later. In conclusion, to use a grabber that normally does not imply motor learning, C.D. shows a process of motor learning that is likely guided by visual information and affects subsequent free-hand movements