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2019

Neural mechanisms of vibrotactile categorization


Abstract

The grouping of sensory stimuli into categories is fundamental to cognition. Previous research in the visual and auditory systems supports a two-stage processing hierarchy that underlies perceptual categorization: (a) a “bottom-up” perceptual stage in sensory cortices where neurons show selectivity for stimulus features and (b) a “top-down” second stage in higher level cortical areas that categorizes the stimulus-selective input from the first stage. In order to test the hypothesis that the two-stage model applies to the somatosensory system, 14 human participants were trained to categorize vibrotactile stimuli presented to their right forearm. Then, during an fMRI scan, participants actively categorized the stimuli. Representational similarity analysis revealed stimulus selectivity in areas including the left precentral and postcentral gyri, the supramarginal gyrus, and the posterior middle temporal gyrus. Crucially, we identified a single category-selective region in the left ventral precentral gyrus. Furthermore, an estimation of directed functional connectivity delivered evidence for robust top-down connectivity from the second to first stage. These results support the validity of the two-stage model of perceptual categorization for the somatosensory system, suggesting common computational principles and a unified theory of perceptual categorization across the visual, auditory, and somatosensory systems.

Citation

article: Malone_2019 doi: 10.1002/hbm.24581 url: https://doi.org/10.1002/hbm.24581 year: 2019 month: mar publisher: Wiley author: Malone Patrick S. and Eberhardt Silvio P. and Wimmer Klaus and Sprouse Courtney and Klein Richard and Glomb Katharina and Scholl Clara A. and Bokeria Levan and Cho Philip and Deco Gustavo and Jiang Xiong and Bernstein Lynne E. and Riesenhuber Maximilian title: Neural mechanisms of vibrotactile categorization journal: Human Brain Mapping

Citation

article: Malone_2019 doi: 10.1002/hbm.24581 url: https://doi.org/10.1002/hbm.24581 year: 2019 month: mar publisher: Wiley author: Malone Patrick S. and Eberhardt Silvio P. and Wimmer Klaus and Sprouse Courtney and Klein Richard and Glomb Katharina and Scholl Clara A. and Bokeria Levan and Cho Philip and Deco Gustavo and Jiang Xiong and Bernstein Lynne E. and Riesenhuber Maximilian title: Neural mechanisms of vibrotactile categorization journal: Human Brain Mapping