Abstract Representations of Surface Stickiness
2019년 4월 3일 업데이트됨
Junsuk Kim, Isabelle Bülthoff, and Heinrich H. Bülthoff
“Even when we are wearing gloves, we can easily detect whether a surface that we are touching is sticky or not. How our brain encode the surface texture irrespective of the touch condition conveying the sticky sensation?”
Even when we are wearing gloves, we can easily detect whether a surface that we are touching is sticky or not. However, we know little about the similarities or commonalities between brain activations elicited by direct and indirect touch. In this fMRI study, we investigated which brain regions represent stickiness intensity information obtained by a bare or gloved hand. First, we searched for neural representations mediating stickiness for each touch condition separately and found regions responding to both conditions mainly in the supramarginal gyrus and the secondary somatosensory cortex. Second, we explored whether surface stickiness is encoded in common neural patterns irrespective of how participants touched the sticky stimuli. Using a cross-condition decoding method, we tested whether the stickiness intensities could be decoded from fMRI signals evoked by direct touch using a classifier trained on the responses elicited by indirect touch, and vice versa. Our results revealed shared neural encoding patterns in the bilateral angular gyri and the inferior frontal gyrus, suggesting these areas as candidates for abstract representations of stickiness intensity. Interestingly, we observed that neural encoding patterns of these areas were reflected in participants’ intensity ratings, demonstrating that the brain encodes perceived intensity not physical intensity itself.
Junsuk Kim, Isabelle Bülthoff, and Heinrich H. Bülthoff, "Abstract Representations of Surface Stickiness in the Human Brain", under review.