A motor-oriented organization of human ventral visual cortex?

Editor's Note: These short, critical reviews of recent papers in the Journal, written exclusively by graduate students or postdoctoral fellows, are intended to summarize the important findings of the paper and provide additional insight and commentary. For more information on the format and purpose of the Journal Club, please see The organizing principles of high-level primate occipitotemporal cortex (OTC) have puzzled cognitive neuroscientists for decades. Whereas visual response properties throughout the early visual system are highly structured and systematic, high-level OTC appears to be arranged as a mosaic of specialized regions, each thought to be involved in the perceptual analysis of particular stimulus categories (e.g. Malach, 2004). Several theories have been proposed to account for this highly modular organization. According to one prominent view, the organization of OTC reflects a mapping based on similarities in the visual shape and form of objects (Haxby et al., 2001). Another view posits that this organization is a byproduct of weak visual field preferences throughout OTC (Levy et al., 2001). Notably, the majority of these theories, in some form or another, attempt to account for the organization of OTC on the basis of the visual structure of the world and/or how it is experienced. Given that many projections to OTC arise from early visual areas (Felle-man and Van Essen, 1991), it is not surprising that most theories should attempt to account for its organization on the basis of incoming visual information. One compelling alternative to these accounts, however, argues that the organization of OTC emerges from the con-nectivity of OTC not just with early visual cortex but, more importantly, with the rest of the brain—particularly the " downstream " regions like parietal and somatomotor cortex that use OTC information to produce motor behavior (Mahon and Caramazza, 2011). In essence , this hypothesis argues that categorical specificity at the level of OTC may largely reflect a manifestation of the connectivity constraints imposed by a much more widely distributed network of areas (beyond that of the ventral visual pathway alone), with the different network specializations reflecting differences in how each stimulus category is ultimately processed, stored, and used by the entire brain to produce action. This hypothesis is provocative, but evidence in support of it is limited. Exciting recent findings in humans (Bracci and Peelen, 2013), however, appear consistent with this account and suggest that understanding the representation of object properties linked to action planning and …