Primary Motor Cortex Involvement in a Handedness Recognition Task – Evidence from Transcranial Magnetic Stimulation

Motor imagery and motor execution share common neural substrates. While the primary motor cortex is crucial for motor execution, its contribution to motor imagery is still debated. We applied transcranial magnetic stimulation (TMS) to the primary motor hand area (M1-HAND) during a hand recognition task to assess the involvement of M1-HAND in motor imagery of body parts. A schematic picture of the back or palm of a human hand was presented at various stimulus orientations. Subjects were required to indicate whether they thought it was a right or a left hand by pressing a button with their right or left toe as fas…