Movement Intention After Parietal Cortex Stimulation in Humans

• Published in: Science (American Association for the Advancement of Science) Vol. 324; no. 5928; pp. 811 - 813
• Main Authors: Desmurget, Michel, Reilly, Karen T, Richard, Nathalie, Szathmari, Alexandru, Mottolese, Carmine, Sirigu, Angela
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 08.05.2009; The American Association for the Advancement of Science
• Subjects: Anatomy; Behavioral neuroscience; Biological and medical sciences; brain; Brain Mapping; Cognition & reasoning; cortex; Desire; Electric Stimulation; Electrical stimulation; electrical treatment; Electricity; Electromyography; Extremities - physiology; Frontal Lobe - physiology; Fundamental and applied biological sciences. Psychology; Humans; Intention; Itching; lips; Medical research; Mental stimulation; Motor ability; Motor cortex; Motor Cortex - physiology; Mouth - physiology; Movement; Neurology; Parietal Lobe - physiology; patients; Physiological stimulation; surgery; Tumors; Vertebrates: nervous system and sense organs; Volition; Human; Lip; Motor pathway; Electrical stimulus; Central nervous system; Parietal cortex; Stimulation; Premotor cortex; Hand; Encephalon; Foot
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1169896

Parietal and premotor cortex regions are serious contenders for bringing motor intentions and motor responses into awareness. We used electrical stimulation in seven patients undergoing awake brain surgery. Stimulating the right inferior parietal regions triggered a strong intention and desire to move the contralateral hand, arm, or foot, whereas stimulating the left inferior parietal region provoked the intention to move the lips and to talk. When stimulation intensity was increased in parietal areas, participants believed they had really performed these movements, although no electromyographic activity was detected. Stimulation of the premotor region triggered overt mouth and contralateral limb movements. Yet, patients firmly denied that they had moved. Conscious intention and motor awareness thus arise from increased parietal activity before movement execution.