Local and distributed information coding in the ventral stream

Neuroscience is awash with studies showing how virtually every cognitive or neural function is distributed across many regions. Yet, it is left unclear whether findings of widespread information processing imply large-scale integrative computations or instead should be seen as showing multitudes of localized modules. To investigate this distinction, we used fMRI data (N=60) from participants viewing objects across four tasks, and we examined the relationships between regions in terms of information coding. We demonstrate that coding in the occipital lobe is overwhelmingly localized and small-scale population codes are the foundation of early perceptual representation. In contrast, different portions of the inferior temporal lobe coordinate as a distributed unit to produce multi-regional population codes for semantic information. No other brain area – neither the parietal nor prefrontal cortices – shows the preference for distributed coding seen in the inferior temporal lobe. The inferior temporal lobe additionally displays uniquely low levels of redundancy in its information coding across its constituent regions, and we demonstrate how this supports lobe-wide semantic processing. Taken together, these results outline a framework of how the ventral stream transitions from local to distributed neuronal coding as information progresses from perceptual to semantic representations.