While it has been known that rapidly comprehending whole words activates an area called the visual word form area (VWFA), the same area is also activated by faces and objects. Gaillard et al have now shown that this area is indispensable for reading whole words, but not faces and objects. In an operation for severe epilespy, they removed a small area near the VWFA. The patient now required 900 milliseconds rather than 600 milliseconds to recognize a three letter word, suggesting a transition from reading the whole word to reading letter by letter.
What is curious is that a task invented only about 6,000 years ago, understanding whole words as entities instead of letter by letter, apparently requires a dedicated brain area. Since this is a very short time for genetic changes that might enable such an area, it seems more likely that this specialzed area forms during language development in each individual as a solution to the problem of rapidly processing written text.