Effects of action observation on physical training after stroke.

Abstract

In healthy humans, observation of another individual performing a motor training task (action observation [AO]) facilitates, in the observer, the effects of physical training (PT) on motor memory formation. It is not known whether this facilitatory process, of potential value for neurorehabilitation, occurs after stroke. Eight chronic stroke patients completed this crossover-randomized investigation. A transcranial magnetic stimulation protocol that tests formation of motor memories was used to determine the effects of PT alone and in combination with AO in 2 different forms: congruent (PT+AO(congruent)) and incongruent (PT+AO(incongruent)) to the practiced task. The magnitude of motor memory formation was larger with PT+AO(congruent) than with PT alone or PT+AO(incongruent). This effect was associated with a differential corticomotor excitability change in the muscles acting as agonist and antagonist of the trained/observed movements. These results indicate that congruent AO in association with physical training can enhance the effects of motor training after stroke.