title: The Effect of Task Instruction on Haptic Texture Processing: The Neural Underpinning of Roughness and Spatial Density Perception.
abstract: Perceived roughness is associated with a variety of physical factors and multiple peripheral afferent types. The current study investigated whether this complexity of the mapping between physical and perceptual space is reflected at the cortical level. In an integrative psychophysical and imaging approach, we used dot pattern stimuli for which previous studies reported a simple linear relationship of interdot spacing and perceived spatial density and a more complex function of perceived roughness. Thus, by using both a roughness and a spatial estimation task, the physical and perceived stimulus characteristics could be dissociated, with the spatial density task controlling for the processing of low-level sensory aspects. Multivoxel pattern analysis was used to investigate which brain regions hold information indicative of the level of the perceived texture characteristics. While information about differences in perceived roughness was primarily available in higher-order cortices, that is, the operculo-insular cortex and a ventral visual cortex region, information about perceived spatial density could already be derived from early somatosensory and visual regions. This result indicates that cortical processing reflects the different complexities of the evaluated haptic texture dimensions. Furthermore, this study is to our knowledge the first to show a contribution of the visual cortex to tactile roughness perception.
authors.affiliation: Department of Cognitive Neuroscience, Maastricht University, The Netherlands.|Brain Innovation B.V., Maastricht, The Netherlands.
authors.forename: Judith
authors.initials: J
authors.lastname: Eck
authors.affiliation: Department of Cognitive Neuroscience, Maastricht University, The Netherlands.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Kaas
authors.affiliation: Brain Innovation B.V., Maastricht, The Netherlands.
authors.forename: Joost L
authors.initials: JL
authors.lastname: Mulders
authors.affiliation: Department of Cognitive Neuroscience, Maastricht University, The Netherlands.
authors.forename: Lars
authors.initials: L
authors.lastname: Hausfeld
authors.affiliation: Department of Psychology, University of Cambridge, Cambridge, UK.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Kourtzi
authors.affiliation: Department of Cognitive Neuroscience, Maastricht University, The Netherlands.|Brain Innovation B.V., Maastricht, The Netherlands.|Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands.
authors.forename: Rainer
authors.initials: R
authors.lastname: Goebel
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D013003:Somatosensory Cortex / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: roughness; somatosensory cortex; spatial density; tactile; visual cortex