The Visual Word Form Area (VWFA) is a brain region that helps us recognize written words and letters. Without it, reading requires much more effort. When a man suffered an accidental lesion to his VWFA during brain surgery, he lost much of his ability to read while losing none of his general language abilities. After six months, he had partially recovered, but reading still took twice as long as it had before (Gaillard et al, 2006).
The VWFA is composed of neurons that were once used for face recognition:
Thus, learning to read must involve a ‘neuronal recycling’ process whereby pre-existing cortical systems are harnessed for the novel task of recognizing written words. … [Such areas of the cortex] possess the appropriate receptive fields to recognize the small contrasted shapes that are used as characters, and the appropriate connections to send this information to temporal lobe language areas (Dehaene & Cohen, 2011)
This neuronal recycling seems to have become hardwired, at least in some people. After Swiss preschoolers played a grapheme/phoneme correspondence game for a total of 3.6 hours over 8 weeks, an MRI scan showed their VWFAs preferentially responding to images of strings of letters. Yet only a few of the children could actually read, and only at a rudimentary level (Brem et al., 2010).
Humans may have initially identified words by using face-recognition neurons. As reading became more important, natural selection favored those humans who could free up more of their face-recognition neurons for reading. This selection eventually created a large neuronal population dedicated solely to word recognition, i.e., the VWFA.
This article discusses how our ability to recognize faces evolved to also recognize the written word, especially in alphabetic languages. The face recognition areas in the brain can also be partially commandeered by the development of word-recognition skills through learning to read. As someone with poor face-recognition, I wonder what happened to me. I also learned to read Chinese, so who knows what was going on? Apparently, recognizing Chinese characters requires yet another region of the brain. Some information about that can be found in this paper: The Visual Word Form Area: Evidence from an fMRI study of implicit processing of Chinese characters. ABN
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