Two-Dimensional Population Receptive Field Mapping of Human Primary Somatosensory Cortex

Asghar, Michael; Sanchez-Panchuelo, Rosa; Schluppeck, Denis; Francis, Susan

Abstract

Functional magnetic resonance imaging can provide detailed maps of how sensory space is mapped in the human brain. Here, we use a novel 16 stimulator setup (a 4 × 4 grid) to measure two-dimensional sensory maps of between and within-digit (D2–D4) space using high spatial-resolution (1.25 mm isotropic) imaging at 7 Tesla together with population receptive field (pRF) mapping in 10 participants. Using a 2D Gaussian pRF model, we capture maps of the coverage of digits D2–D5 across Brodmann areas and estimate pRF size and shape. In addition, we compare results to previous studies that used fewer stimulators by constraining pRF models to a 1D Gaussian Between Digit or 1D Gaussian Within Digit model. We show that pRFs across somatosensory areas tend to have a strong preference to cover the within-digit axis. We show an increase in pRF size moving from D2–D5. We quantify pRF shapes in Brodmann area (BA) 3b, 3a, 1, 2 and show differences in pRF size in Brodmann areas 3a-2, with larger estimates for BA2. Generally, the 2D Gaussian pRF model better represents pRF coverage maps generated by our data, which itself is produced from a 2D stimulation grid.

• Journal Article Type: Article
• Acceptance Date: Aug 9, 2023
• Online Publication Date: Aug 27, 2023
• Publication Date: 2023-11
• Deposit Date: Aug 15, 2023
• Publicly Available Date: Aug 28, 2024
• Journal: Brain Topography
• Print ISSN: 0896-0267
• Electronic ISSN: 1573-6792
• Publisher: Springer Science and Business Media LLC
• Peer Reviewed: Peer Reviewed
• Volume: 36
• Pages: 816-834
• DOI: https://doi.org/10.1007/s10548-023-01000-8
• Keywords: Population receptive fields; 7T fMRI; Primary somatosensory cortex; Primary motor cortex; Somatotopy
• Public URL: https://nottingham-repository.worktribe.com/output/24399338
• Publisher URL: https://link.springer.com/article/10.1007/s10548-023-01000-8