Schedule of Events | Symposia

Alignment of visual and tactile motion directions in external space: hMT+/V5 and beyond

Poster Session F - Tuesday, April 1, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Iqra Shahzad^1,2, Ceren Battal^1,2, Filippo Cerpelloni^1,2,5, Alice Van Audenhaege^1,2, André Mouraux¹, Olivier Collignon^1,2,3; ¹Institute of Neuroscience (IoNS), Université Catholique de Louvain, ²Institute of Research in Psychological Sciences (IPSY), Université Catholique de Louvain, ³HES-SO Valais-Wallis, The Sense Innovation and Research Center, ⁴Brain and cognition, Leuven Brain Institute, KU Leuven, Belgium

Moving events on the skin can be perceived through vision and touch. How does the brain create a unified multisensory representation of motion acquired across the senses in different coordinate systems? We show that the middle occipito-temporal region (hMT+/V5), along with dorsal stream regions, encodes visual and tactile directions using a common external frame of reference independent of body posture. In an fMRI experiment, we delivered directional visual and tactile motion stimuli across different hand postures. We first demonstrate that individually-defined hMT+/V5 shows univariate preference for both visual and tactile motion and encodes motion directions in distributed activity patterns. Unlike somatosensory regions, information about tactile directions was enhanced in hMT+/V5 when mapped using an external frame of reference as compared to a somatotopic frame of reference. Crossmodal decoding showed that tactile directions defined using an externally-centered coordinate system, but not a somatotopic one, align with the representation of visual directions in hMT+/V5. A whole brain group analysis confirmed these individually defined regions-of-interest results and extended the presence of an aligned visuo-tactile code for directional motion in external space to the parietal and dorsal prefrontal cortex. Our findings reveal a brain network involving hMT+/V5 that encodes motion directions in vision and touch using a common external frame of reference.

Topic Area: PERCEPTION & ACTION: Multisensory