Observational Learning in Stroke Patients

In normal subjects, the learning of new hand movements initially relies on the automatic ability to elaborate a motor plan from the simple observation of movements performed by others. The improvement of motor performance during practice also relies on a correct visuomotor processing of visual feedback and it has been demonstrated that the repeated observation of a gesture, named observational training is sufficient to induce motor learning. However, it is not known if stroke patients process visuomotor information in the same manner as normal subjects. Objectives: The purpose of this protocol is to determine the pattern of brain activations related to motor learning induced by observational training in stroke patients as compared to normal volunteers. We hypothesize that observational motor learning in stroke patients will rely on an increased activity in premotor cortex as compared to normal volunteers. Study population: This protocol will include chronic stroke patients with subcortical lesions and good motor recovery from an initial upper-limb paresis, and a control population of age and gender matched normal volunteers. Design: We will conduct a functional MRI (fMRI) experiment assessing observational training of finger sequences. Three conditions of finger sequences will be compared: 1) a sequence visually trained during the fMRI session, 2) a non-trained sequence (control 1), and 3) a sequence visually trained before the fMRI session (control 2). The fMRI session will be split into 3 separate runs. The first run will assess brain activity related to the motor performance of the 3 finger sequences. The second run will explore the brain activity during observational training of the sequence. The third run will re-assess the brain activity related to the motor performance of the 3 finger sequences. Outcome measures: The endpoint measure of the experiment will be an increase in the number of activated voxels in premotor cortex during the motor learning induced by observational training in the stroke patients as compared to normal volunteers.