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A real red-letter day

Synesthesia, in which letters or numbers elicit color perception, could be due to increased brain connectivity between relevant regions, or due to failure to inhibit feedback in cortical circuits. Diffusion tensor imaging now provides evidence for increased connectivity in word processing and binding regions of the brain.

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Figure 1: The outer cortical surface with relevant brain regions indicated.


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Hubbard, E. A real red-letter day. Nat Neurosci 10, 671–672 (2007).

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