Imagining and reading actions: Towards similar motor representations

While action language and motor imagery both engage the motor system, determining whether these two processes indeed share the same motor representations would contribute to better understanding their underlying mechanisms. We conducted two experiments probing the mutual influence of these two processes. In Exp.1, hand-action verbs were presented subliminally, and participants (n = 36) selected the verb they thought they perceived from two alternatives. When congruent actions were imagined prior to this task, accuracy significantly increased, i.e. partic-ipants were better able to "see" the subliminal verbs. In Exp.2, participants (n = 19) imagined hand flexion or extension, while corticospinal excitability was measured via transcranial mag-netic stimulation. Corticospinal excitability was modulated by action verbs subliminally pre-sented prior to imagery. Specifically, the typical increase observed during imagery was suppressed after presentation of incongruent action verbs. This mutual influence of action lan-guage and motor imagery, both at behavioral and neurophysiological levels, suggests overlapping motor representations.