RT Journal Article
SR Electronic
T1 Supramodal Shape Representation in the Human Brain
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.11.22.517472
DO 10.1101/2022.11.22.517472
A1 Yangwen Xu
A1 Lorenzo Vignali
A1 Federica Sigismondi
A1 Davide Crepaldi
A1 Roberto Bottini
A1 Olivier Collignon
YR 2022
UL http://biorxiv.org/content/early/2022/11/23/2022.11.22.517472.abstract
AB We can sense an object’s shape by vision or touch. Previous studies suggested that the inferolateral occipitotemporal cortex (ILOTC) implements supramodal shape representations as it responds more to seeing or touching objects than shapeless textures. However, such activation in the anterior portion of the ventral visual pathway could be due to the conceptual representation of an object or visual imagery triggered by touching an object. We addressed these possibilities by directly comparing shape and conceptual representations in early blind (who lack visual experience/imagery) and sighted participants. We found that bilateral ILOTC in both groups showed stronger activation during a shape verification task than during a conceptual verification task made on the names of the same manmade objects. Moreover, the distributed activity in the ILOTC encoded shape similarity but not conceptual association among objects. Besides the ILOTC, we also found shape representation in both groups’ bilateral ventral premotor cortices and intraparietal sulcus, a frontoparietal circuit relating to object grasping and haptic processing. In contrast, the conceptual verification task activated both groups’ left perisylvian brain network relating to language processing, and, interestingly, the cuneus in early blind participants only. The ILOTC had stronger functional connectivity to frontoparietal circuit than to the left perisylvian network, forming a modular structure specialized in shape representation. Our results conclusively support that the ILOTC selectively implements shape representation independently of visual experience, and this unique functionality likely comes from its privileged connection to the frontoparietal haptic circuit.Competing Interest StatementThe authors have declared no competing interest.