Similar object shape representation encoded in the inferolateral occipitotemporal cortex of sighted and early blind people

PLoS Biol. 2023 Jul 25;21(7):e3001930. doi: 10.1371/journal.pbio.3001930. eCollection 2023 Jul.


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 of objects 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 (IPS), 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 the 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blindness
  • Brain Mapping
  • Cerebral Cortex*
  • Humans
  • Magnetic Resonance Imaging / methods
  • Occipital Lobe
  • Parietal Lobe / physiology
  • Touch / physiology
  • Touch Perception* / physiology

Grants and funding

This work was supported by the Belgian Excellence of Science (EOS) program (Project No. 30991544) attributed to O.C., the Research Projects of National Interest (PRIN) grant from the Italian Ministry of Education, University and Research (MIUR) attributed to D.C. and O.C. (Project No. 2015PCNJ5F_001), the Flag-ERA HBP PINT-MULTI (R.8008.19) attributed to O.C., and a mandate d’impulsion scientifique from the Fonds National de la Recherche Scientifique de Belgique (FRS-FNRS) attributed to O.C. O.C. is a research associate at the Fonds National de la Recherche Scientifique de Belgique (FRS-FNRS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.