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Updated: Aug 24, 2026

Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation
Published on: February 23, 2020
Foot, face and hand representation in the human supplementary motor area
Hanna Chainay1, Alexandre Krainik, Marie-Laure Tanguy
1Department of Neuroradiology, INSERM U610, Hôpital de la Salpêtrière, 47 Boulevard de l'Hôpital, 75651 Paris CEDEX, France.
Abstract:
The ability to localize the limb representation in the supplementary motor area (SMA) would be useful in planning surgical ablation of medial frontal lobe tumours. We investigated the relationship between the anatomy of the SMA and the functional representation of fingers, toes, and lips using fMRI in healthy volunteers. There was a significant difference between the location of the different body parts in the SMA, with a rostro-caudal location of the face, hand and foot areas. Limb representation was located in an area spanning < 1 cm rostral and 1 cm caudal to the paracentral sulcus. These results support the somatotopic organization of the human SMA and suggest that the paracentral sulcus represents a landmark for body representation.
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