Motor impairment evoked by direct electrical stimulation of human parietal cortex during object manipulation

Luca Fornia, Marco Rossi, Marco Rabuffetti, Andrea Bellacicca, Luca Viganò, Luciano Simone, Henrietta Howells, Guglielmo Puglisi, Antonella Leonetti, Vincenzo Callipo, Lorenzo Bello, Gabriella Cerri

Research output: Contribution to journalArticlepeer-review


In primates, the parietal cortex plays a crucial role in hand-object manipulation. However, its involvement in object manipulation and related hand-muscle control has never been investigated in humans with a direct and focal electrophysiological approach. To this aim, during awake surgery for brain tumors, we studied the impact of direct electrical stimulation (DES) of parietal lobe on hand-muscles during a hand-manipulation task (HMt). Results showed that DES applied to fingers-representation of postcentral gyrus (PCG) and anterior intraparietal cortex (aIPC) impaired HMt execution. Different types of EMG-interference patterns were observed ranging from a partial (task-clumsy) or complete (task-arrest) impairment of muscles activity. Within PCG both patterns coexisted along a medio (arrest)–lateral (clumsy) distribution, while aIPC hosted preferentially the task-arrest. The interference patterns were mainly associated to muscles suppression, more pronounced in aIPC with respect to PCG. Moreover, within PCG were observed patterns with different level of muscle recruitment, not reported in the aIPC. Overall, EMG-interference patterns and their probabilistic distribution suggested the presence of different functional parietal sectors, possibly playing different roles in hand-muscle control during manipulation. We hypothesized that task-arrest, compared to clumsy patterns, might suggest the existence of parietal sectors more closely implicated in shaping the motor output.

Original languageEnglish
Article number118839
Publication statusE-pub ahead of print - Dec 25 2021


  • EMG
  • hand-manipulation
  • Human Parietal cortex
  • intraoperative stimulation
  • motor control

ASJC Scopus subject areas

  • Neurology
  • Cognitive Neuroscience


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