title: Seeing touch is correlated with content-specific activity in primary somatosensory cortex.
abstract: There is increasing evidence to suggest that primary sensory cortices can become active in the absence of external stimulation in their respective modalities. This occurs, for example, when stimuli processed via one sensory modality imply features characteristic of a different modality; for instance, visual stimuli that imply touch have been observed to activate the primary somatosensory cortex (SI). In the present study, we addressed the question of whether such cross-modal activations are content specific. To this end, we investigated neural activity in the primary somatosensory cortex of subjects who observed human hands engaged in the haptic exploration of different everyday objects. Using multivariate pattern analysis of functional magnetic resonance imaging data, we were able to predict, based exclusively on the activity pattern in SI, which of several objects a subject saw being explored. Along with previous studies that found similar evidence for other modalities, our results suggest that primary sensory cortices represent information relevant for their modality even when this information enters the brain via a different sensory system.
authors.affiliation: Brain and Creativity Institute, University of Southern California, 3641 Watt Way, Suite 126, Los Angeles, CA 90089-2520, USA. kaspar.meyer@usc.edu
authors.forename: Kaspar
authors.initials: K
authors.lastname: Meyer
authors.forename: Jonas T
authors.initials: JT
authors.lastname: Kaplan
authors.forename: Ryan
authors.initials: R
authors.lastname: Essex
authors.forename: Hanna
authors.initials: H
authors.lastname: Damasio
authors.forename: Antonio
authors.initials: A
authors.lastname: Damasio
mesh_terms: D000704:Analysis of Variance; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009040:Motion Pictures; D010775:Photic Stimulation; D011434:Proprioception / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*