The Effect of Visual Experience on the Development of Functional Architecture in hMT+

TLDR

The study examined whether hMT+ contributes to a supramodal representation of sensory flow independent of visual imagery. Functional MRI was used to record neural responses in sighted and congenitally blind participants during passive optic and tactile flow perception. In sighted subjects hMT+ responded to optic flow and only the anterior part to tactile flow, whereas blind subjects showed full activation for tactile flow, indicating that hMT+ can develop tactile flow representation without vision and that visual experience segregates the region into an anterior dual‑flow subregion and a posterior optic‑only subregion.

Abstract

We investigated whether the visual hMT+ cortex plays a role in supramodal representation of sensory flow, not mediated by visual mental imagery. We used functional magnetic resonance imaging to measure neural activity in sighted and congenitally blind individuals during passive perception of optic and tactile flows. Visual motion-responsive cortex, including hMT+, was identified in the lateral occipital and inferior temporal cortices of the sighted subjects by response to optic flow. Tactile flow perception in sighted subjects activated the more anterior part of these cortical regions but deactivated the more posterior part. By contrast, perception of tactile flow in blind subjects activated the full extent, including the more posterior part. These results demonstrate that activation of hMT+ and surrounding cortex by tactile flow is not mediated by visual mental imagery and that the functional organization of hMT+ can develop to subserve tactile flow perception in the absence of any visual experience. Moreover, visual experience leads to a segregation of the motion-responsive occipitotemporal cortex into an anterior subregion involved in the representation of both optic and tactile flows and a posterior subregion that processes optic flow only.