An imaging study of 10 illiterates, 22 people who learned to read as adults and 31 who did so as children, has confirmed that the visual word form area (involved in linking sounds with written symbols) showed more activation in better readers, although everyone had similar levels of activation in that area when listening to spoken sentences. More importantly, it also revealed that this area was much less active among the better readers when they were looking at pictures of faces.
Other changes in activation patterns were also evident (for example, readers showed greater activation in the planum temporal in response to spoken speech), and most of the changes occurred even among those who acquired literacy in adulthood — showing that the brain re-structuring doesn’t depend on a particular time-window.
The finding of competition between face and word processing is consistent with the researcher’s theory that reading may have hijacked a neural network used to help us visually track animals, and raises the intriguing possibility that our face-perception abilities suffer in proportion to our reading skills.
(2010). How Learning to Read Changes the Cortical Networks for Vision and Language.