Connectivity precedes function in the development of the visual word form area

What determines the cortical location where a given functionally specific region will arise in development? Here we test the hypothesis that functionally specific regions develop in their characteristic locations because of pre-existing differences in the extrinsic connectivity of that region to the rest of the brain. We exploit the Visual Word Form Area (VWFA) as a test case, scanning children with diffusion and functional imaging at age five, before they learned to read, and at age 8, after they learned to read. We find the VWFA develops functionally in this interval and that its location in a particular child at age 8 can be predicted from that child’s connectivity fingerprints (but not functional responses) at age 5. These results suggest that early connectivity instructs the functional development of the VWFA, possibly reflecting a general mechanism of cortical development. Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:http://www.nature.com/authors/editorial_policies/license.html#terms Correspondence should be addressed to Z.M.S. (zsaygin@mit.edu). AUTHOR CONTRIBUTIONS Z.M.S., D.E.O., and N.K designed the experiments. Z.M.S., E.S.N, D.A.Y., S.D.B., N.G., J.D.E.G. and N.K. conducted the experiments or supplied data. Z.M.S., D.E.O., D.A.Y., and J.F. analyzed the data. Z.M.S., D.E.O., and N.K. wrote the manuscript. COMPETING FINANCIAL INTERESTS The authors declare no competing financial interests. A Supplementary Methods Checklist is available. HHS Public Access Author manuscript Nat Neurosci. Author manuscript; available in PMC 2017 March 01. Published in final edited form as: Nat Neurosci. 2016 September ; 19(9): 1250–1255. doi:10.1038/nn.4354. A uhor M anscript