Selective Visuo-Haptic Processing of Shape and Texture

• Type of Material: Article
• Authors: Randall Stilla, Emory University; Krish Sathian, Emory University
• Language: English
• Date: 2008-10
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2007 Wiley‐Liss, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1002%2Fhbm.20456
• Title of Journal or Parent Work: Human Brain Mapping
• ISSN: 1065-9471
• Volume: 29
• Issue: 10
• Start Page: 1123
• End Page: 1138
• Grant/Funding Information: Support to KS from the Veterans Administration is also gratefully acknowledged.; This work was supported by NIH grants R01 EY12440 and K24 EY17332 to KS.
• Keywords: cross-modal; perception; somatosensory cortex; fMRI; visual cortex; bisensory; Multisensory; hand; tactile
• Research Categories: Biology, Neuroscience; Health Sciences, Rehabilitation and Therapy; Psychology, Cognitive

Abstract

Previous functional neuroimaging studies have described shape-selectivity for haptic stimuli in many cerebral cortical regions, of which some are also visually shape-selective. However, the literature is equivocal on the existence of haptic or visuo-haptic texture-selectivity. We report here on a human functional magnetic resonance imaging (fMRI) study in which shape and texture perception were contrasted using haptic stimuli presented to the right hand, and visual stimuli presented centrally. Bilateral selectivity for shape, with overlap between modalities, was found in a dorsal set of parietal areas: the postcentral sulcus and anterior, posterior and ventral parts of the intraparietal sulcus; as well as ventrally in the lateral occipital complex. The magnitude of visually- and haptically-evoked activity was significantly correlated across subjects in the left posterior intraparietal sulcus and right lateral occipital complex, suggesting that these areas specifically house representations of object shape. Haptic shape-selectivity was also found in the left postcentral gyrus, the left lingual gyrus and a number of frontal cortical sites. Haptic texture-selectivity was found in ventral somatosensory areas: the parietal operculum and posterior insula bilaterally, as well as in the right medial occipital cortex, overlapping with a medial occipital cortical region which was texture-selective for visual stimuli. The present report corroborates and elaborates previous suggestions of specialized visuo-haptic processing of texture and shape.