Not exactly what OP mentioned, but [1] is a potential starting point to look into. I didn't even know there were functional (as opposed to morphological) areas

Not exactly what OP mentioned, but [1] is a potential starting point to look into. I didn't even know there were functional (as opposed to morphological) areas of the brain already mapped to a precision that size could be accurately compared between samplings, but there seems to be some MRI-based work on that [2]. Anything I could find on the changes between generations of the functional areas of the brain are along the lines of [3], at evolutionary time scales instead of successive generations. [1] https://en.wikipedia.org/wiki/Evolution_of_the_brain https://en.wikipedia.org/wiki/Evolution_of_the_brain [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2705206/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2705206/ [3] http://www.indiana.edu/~brainevo/publications/annurev.anthro.35.pdf http://www.indiana.edu/~brainevo/publications/annurev.anthro...