Thursday, November 25, 2010
Unlike speech, there isn't a portion of the human brain devoted to reading or writing. We're not hardwired to do either and thus neuroscientists are beginning to ask whether the cognitive resources used for those activities come at the expense of other skills. As reported in the Chronicle of Higher Ed:
[R]eading is one of those complex skills that emerged in an evolutionary blink of the eye, in the Middle East about 5,000 years ago. It is also a skill reserved until the last two centuries for a very small percentage of humanity. That’s a strong circumstantial case that to read we must be appropriating parts of the brain that evolved for other purposes and re-wiring them to make sense of written language.
. . . .
[Leading French researcher] Dehaene and his colleagues recruited volunteers in three groups: people who became literate in childhood, people who learned to read as adults, and illiterates. They then used brain imaging to find the ways in which literate and illiterate brains differ. As Science summarizes it, 'the junction of the left occipital and temporal lobes of the brain' and 'parts of the left temporal lobe that respond to spoken language' differ between literate and illiterate brains. When something gets 'repurposed,' it stands to reason that the original purpose might not be served quite so well. Does literacy bring tradeoffs?
Maybe. If you learn to read as a child, the part of the occipital-temporal cortex that recognizes human faces is smaller than it is in people who learn to read later or who remain illiterate. Dehaene and his colleagues don’t yet know whether the difference in size translates into a degradation of ability.
You can read the rest here.