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Updated: Jul 7, 2026

Visualization of Cortical Modules in Flattened Mammalian Cortices
Published on: January 22, 2018
Segmentally arranged somatotopy within the face representation of human primary somatosensory cortex
Eric A Moulton1, Gautam Pendse, Susie Morris
1PAIN Group, Brain Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA. emoulton@mclean.harvard.edu
Abstract:
Though somatotypic representation within the face in human primary somatosensory cortex (S1) to innocuous stimuli is controversial; previous work suggests that painful heat is represented based on an "onion-skin" or segmental pattern on the face. The aim of this study was to determine if face somatotopy for brush stimuli in S1 also follows this segmental representation model. Twelve healthy subjects (nine men: three women) underwent functional magnetic resonance imaging to measure blood oxygen level dependent signals during brush (1 Hz, 15 s) applied to their faces. Separate functional scans were collected for brush stimuli repetitively applied to each of five separate stimulation sites on the right side of the face. These sites were arranged in a vertical, horizontal, and circular manner encompassing the three divisions of the trigeminal nerve. To minimize inter-individual morphological differences in the post-central gyrus across subjects, cortical surface-based registration was implemented before group statistical image analysis. Based on activation foci, somatotopic activation in the post-central gyrus was detected for brush, consistent with the segmental face representation model.
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