1 research outputs found
Decoding visual roughness perception: an fMRI study
The neural substrates of tactile roughness perception have been investigated by many neuroimaging
studies, while relatively little effort has been devoted to the investigation of neural representations of
visually perceived roughness. In this human fMRI study, we looked for neural activity patterns that
could be attributed to five different roughness intensity levels when the stimuli were perceived visually,
i.e., in absence of any tactile sensation. During functional image acquisition, participants viewed
video clips displaying a right index fingertip actively exploring the sandpapers that had been used for
the behavioural experiment. A whole brain multivariate pattern analysis found four brain regions in
which visual roughness intensities could be decoded: the bilateral posterior parietal cortex (PPC), the
primary somatosensory cortex (S1) extending to the primary motor cortex (M1) in the right hemisphere,
and the inferior occipital gyrus (IOG). In a follow-up analysis, we tested for correlations
between the decoding accuracies and the tactile roughness discriminability obtained from a preceding
behavioural experiment. We could not find any correlation between both although, during scanning,
participants were asked to recall the tactilely perceived roughness of the sandpapers. We presume
that a better paradigm is needed to reveal any potential visuo-tactile convergence. However, the present
study identified brain regions that may subserve the discrimination of different intensities of visual
roughness. This finding may contribute to elucidate the neural mechanisms related to the visual
roughness perception in the human brain.© 2018 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
Group