Category trumps shape as an organizational principle of object space in the human occipitotemporal cortex

Abstract

The organizational principles of the object space represented in human ventral visual cortex are debated. Here we contrast two prominent proposals that, in addition to an organization in terms of animacy, propose either a representation related to aspect ratio or to the distinction between faces and bodies. We designed a critical test that dissociates the latter two categories from aspect ratio and investigated responses from human fMRI and deep neural networks (BigBiGAN). Representational similarity and decoding analyses showed that the object space in occipitotemporal cortex (OTC) and BigBiGAN was partially explained by animacy but not by aspect ratio. Data-driven approaches showed clusters for face and body stimuli and animate-inanimate separation in the representational space of OTC and BigBiGAN, but no arrangement related to aspect ratio. In sum, the findings go in favor of a model in terms of an animacy representation combined with strong selectivity for faces and bodies.