Abstract
Perceiving the distance of an object from the self is a fundamental feature of the visual system. Here we used fMRI to test the hypothesis that the ventral visual stream represents distance-related information in discrete cortical regions. In particular, object-related regions (Lateral Occipital Complex - LOC) are biased towards proximal stimuli, whereas scene-related regions (Parahipocampal Place Area - PPA) are biased towards distant stimuli. Participants were presented with Ponzo lines, which create an illusion of depth. In one condition, the stimuli (pictures of objects or houses) appeared in the perceived proximal position. In the second condition, the stimuli appeared in the perceived distal position. In addition, we ran a localizer, which included scenes, objects and scrambled images of objects. We defined for each subject the PPA (Scenes [[gt]] Objects, p −4, uncorrected) and the LOC (Objects [[gt]] Scrambled Objects, p −4, uncorrected). Consistent with our hypothesis, we found a double dissociation such that object areas showed a higher response to perceived proximal stimuli than perceived distal stimuli, whereas scene-related regions showed a higher response to perceived distal objects than perceived proximal objects. Importantly, this effect was found for both objects and houses. This outcome suggests the plausibility of a distance principle of organization of the ventral visual stream.