[1] Univ Siena, Dept Med Surg & Neurosci, Neurol & Clin Neurophysiol Sect, SiBIN Lab,Brain Invest & Neuromodulat Lab, I-53100 Siena, Italy
[2] Univ Siena, Human Physiol Sect, Dept Med Surg & Neurosci, I-53100 Siena, Italy
[3] Univ Siena, Dept Informat Engn & Math, Siena Robot & Syst Lab, I-53100 Siena, Italy
[4] Harvard Med Sch, Beth Israel Med Ctr, Berenson Allen Ctr Noninvas Brain Stimulat, Boston, MA USA