Distinct yet proximal face- and body-selective brain regions enable clutter-tolerant representations of the face, body and whole person.

Abstract

Faces and bodies are processed in separate but adjacent regions in primate visual cortex. Yet, the functional significance of dividing the whole person into areas dedicated to its face and body components and their neighboring locations remains unknown. Here we hypothesized that this separation and proximity together with a normalization mechanism generate clutter-tolerant representations of the face, body and whole person when presented in complex multi-category scenes. To test this hypothesis, we conducted a fMRI study, presenting images of a person within a multi-category scene to human male and female participants and assessed the contribution of each component to the response to the scene. Our results revealed a clutter-tolerant representation of the whole person in areas selective for both faces and bodies, typically located at the border between the two category-selective regions. Regions exclusively selective for faces or bodies demonstrated clutter-tolerant representations of their preferred category, corroborating earlier findings. Thus, the adjacent locations of face- and body-selective areas enable a hardwired machinery for decluttering of the whole person, without the need for a dedicated population of person-selective neurons. Thus, the distinct yet proximal functional organization of category-selective brain regions enhances the representation of the socially significant whole person, along with its face and body components, within multi-category scenes.Significance statement It is well established that faces and bodies are processed by dedicated brain areas that reside in nearby locations in primates' high-level visual cortex. However, the functional significance of the division of the whole person to its face and body components, their neighboring locations and the absence of a distinct neuronal population selective for the meaningful whole person remained puzzling. Here we proposed a unified solution to these fundamental open questions. We show that consistent with predictions of a normalization mechanism, this functional organization enables a hardwired machinery for decluttering the face, body and the whole person. This generates enhanced processing for the socially meaningful whole person and its significant face and body components in multi-category scenes.