Konkle, TaliaCaramazza, Alfonso2014-06-242013Konkle, Talia A., and Alfonso Caramazza. 2013. “Tripartite Organization of the Ventral Stream by Animacy and Object Size.” Journal of Neuroscience 33, no. 25: 10235–10242.0270-6474http://nrs.harvard.edu/urn-3:HUL.InstRepos:12362624Occipito-temporal cortex is known to house visual object representations, but the organization of the neural activation patterns along this cortex is still being discovered. Here we found a systematic, large-scale structure in the neural responses related to the interaction between two major cognitive dimensions of object representation: animacy and real-world size. Neural responses were measured with functional magnetic resonance imaging while human observers viewed images of big and small animals and big and small objects. We found that real-world size drives differential responses only in the object domain, not the animate domain, yielding a tripartite distinction in the space of object representation. Specifically, cortical zones with distinct response preferences for big objects, all animals, and small objects, are arranged in a spoked organization around the occipital pole, along a single ventromedial, to lateral, to dorsomedial axis. The preference zones are duplicated on the ventral and lateral surface of the brain. Such a duplication indicates that a yet unknown higher-order division of labor separates object processing into two substreams of the ventral visual pathway. Broadly, we suggest that these large-scale neural divisions reflect the major joints in the representational structure of objects and thus place informative constraints on the nature of the underlying cognitive architecture.en-USJournal Article2014-06-2410.1523/JNEUROSCI.0983-13.2013