A Hypothesis:

The wiring of the brain recapitulates the real external physical networks on which we travel (or our perception of it). If people are learning a map (e.g London taxicab drivers learning The Knowledge), they reshape their brain. The newish technical term for this set of internal brain connections is the Connectome. It would make some sense for this wiring to be topologically similar to the actual topology that is being reflected (i.e. one thinks there would be some parsimony in finding the shortest path on a physical network if it were actually the shortest path in the brain).

I realize (and wikipedia tells me so) that classical Recapitulation Theory (Ontogeny Recapitulates Phylogeny “in developing from embryo to adult, animals go through stages resembling or representing successive stages in the evolution of their remote ancestors” ) is disproven.
What I am hypothesizing is different that there is a non-random (statistically significant) resemblance between brain wiring and the physical relationships of the external world.
Now to test. How to test?
Other links:

KurzweilAI reports: Complex wiring of the nervous system may rely on a just a handful of genes and proteins and researchers are working on mapping the internals of the brain.