A somatosensory and premotor network for the cortical mapping of actions: a 1Hz rTMS investigation
Poster Presentation

Nadia Bolognini
Dipartimento di Psicologia, Università di Milano-Bicocca

Alessio Avenanti
Dipartimento di Psicologia, Università degli studi di Roma “La Sapienza”

Angelo Maravita
Dipartimento di Psicologia, Università di Milano-Bicocca

Salvatore M Aglioti
Dipartimento di Psicologia, Università degli studi di Roma “La Sapienza”

     Abstract ID Number: 92
     Full text: Not available
     Last modified: March 17, 2006
     Presentation date: 06/18/2006 4:00 PM in Hamilton Building, Foyer
     (View Schedule)

Abstract
Transcranial Magnetic Stimulation studies indicate that observing another person’s action can selectively facilitate the corticospinal motor representation of the muscles involved in the observed movement. This phenomenon is functionally akin to the “mirror” activation of premotor neurons in the monkey. Cortico-cortical projections from the inferior frontal gyrus (IFG) to the primary motor cortex (M1) seem to play a major role in enhancing cortico-spinal excitability during action observation. Nonetheless, there is evidence suggesting an involvement of somatosensory areas in mirror motor functions. Here we explore the effects of disruption of motor and somatosensory activity on motor mirror responses. MEPs to focal single-pulse TMS over M1 during the observation of bio-mechanically possible and impossible movements were recorded in a baseline condition and after repetitive TMS over S1, M1 and IFG. Both in the baseline and after M1 disruption, we found a significant MEP facilitation, specific for the muscle involved in the observed movement and comparable for possible and impossible movements. By contrast, interference with IFG and S1 selectively reduced MEPs for possible movements and impossible movements respectively. These results suggest that a complex somatosensory and premotor network is necessary for the cortical mapping of different aspects of observed actions.