S1 represents multisensory contexts and somatotopic locations within and outside the bounds of the cortical homunculus
Isabelle A. Rosenthal,
Luke Bashford,
Spencer Kellis,
Kelsie Pejsa,
Brian Lee,
Charles Liu,
Richard A. Andersen
Affiliations
Isabelle A. Rosenthal
Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA; Corresponding author
Luke Bashford
Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA
Spencer Kellis
Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA; Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA 90033, USA
Kelsie Pejsa
Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA
Brian Lee
Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA 90033, USA
Charles Liu
Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; Rancho Los Amigos National Rehabilitation Center, Downey, CA 90242, USA
Richard A. Andersen
Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA
Summary: Recent literature suggests that tactile events are represented in the primary somatosensory cortex (S1) beyond its long-established topography; in addition, the extent to which S1 is modulated by vision remains unclear. To better characterize S1, human electrophysiological data were recorded during touches to the forearm or finger. Conditions included visually observed physical touches, physical touches without vision, and visual touches without physical contact. Two major findings emerge from this dataset. First, vision strongly modulates S1 area 1, but only if there is a physical element to the touch, suggesting that passive touch observation is insufficient to elicit neural responses. Second, despite recording in a putative arm area of S1, neural activity represents both arm and finger stimuli during physical touches. Arm touches are encoded more strongly and specifically, supporting the idea that S1 encodes tactile events primarily through its topographic organization but also more generally, encompassing other areas of the body.
