Hang Joon Jo1, Ziad S. Saad1, Steve J. Gotts2, Richard C. Reynolds1, Patricia Christidis1, Daniel R. Glen1, Alex Martin2, Robert W. Cox1
1Statistical & Scientific Computing Core, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; 2Cognitive Neuropsychology Section, Laboratory of Brain & Cognition, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
We evaluate the fine organization of cross-hemispheric correlations maps in a variety of brain regions outside somatotopic cortex, including occipital, temporal, and prefrontal areas. We find that the fine-grained nature of the symmetric correlation maps carries over more generally to these other areas of cortex. However, we also find that this property carries over equally well to parts of primary visual cortex that have no direct callosal connections, namely the cortex along the depth of the calcarine sulcus that represents the horizontal meridian in V1. Our results highlight the importance of considering alternative mechanisms even in circumstances in which callosal connections are indeed plausible.