Another book to add to my bookshelf of "monographs that blend cultural history with neuroscience" (along with Raymond Tallis' The Hand: A Philosophical Inquiry into Human Being): Maryann Wolf's Proust and the Squid, which Caleb Crain reviews in the latest New Yorker.
Taking the long view, it’s not the neglect of reading that has to be explained but the fact that we read at all. “The act of reading is not natural,” Maryanne Wolf writes in Proust and the Squid, an account of the history and biology of reading. Humans started reading far too recently for any of our genes to code for it specifically. We can do it only because the brain’s plasticity enables the repurposing of circuitry that originally evolved for other tasks—distinguishing at a glance a garter snake from a haricot vert, say.
Elsewhere, as she puts it, “The brain’s design made reading possible, and reading’s design changed the brain in multiple, critical, still evolving ways.”
This isn't a radical argument. As Stanislas Dehaene theorized in a 2003 New Scientist article,
learning to read, and other forms of cultural learning, are only possible if this built-in flexibility can be used to divert brain circuits from their previous uses. The brain is predisposed to develop only in certain ways. In effect, we are able to learn to read because the primate visual system evolved to do a different job that was sufficiently similar to allow it to be "recycled" into a reading machine.
There are two things really interesting about her argument, at least as it comes filtered through the reviews. First, Wolf argues that what's impressive about reading isn't that it's hard, but that it can be easy, because the brain learns to specialize, devoting certain sections to recognizing letters.
Wolf recounts the early history of reading, speculating about developments in brain wiring as she goes. For example, from the eighth to the fifth millennia B.C.E., clay tokens were used in Mesopotamia for tallying livestock and other goods. Wolf suggests that, once the simple markings on the tokens were understood not merely as squiggles but as representations of, say, ten sheep, they would have put more of the brain to work. She draws on recent research with functional magnetic resonance imaging (fMRI), a technique that maps blood flow in the brain during a given task, to show that meaningful squiggles activate not only the occipital regions responsible for vision but also temporal and parietal regions associated with language and computation. If a particular squiggle was repeated on a number of tokens, a group of nerves might start to specialize in recognizing it, and other nerves to specialize in connecting to language centers that handled its meaning….
[R]ecent imaging studies… [show] how a modern child’s brain wires itself for literacy. The ground is laid in preschool, when parents read to a child, talk with her, and encourage awareness of sound elements like rhyme and alliteration, perhaps with “Mother Goose” poems. Scans show that when a child first starts to read she has to use more of her brain than adults do. Broad regions light up in both hemispheres. As a child’s neurons specialize in recognizing letters and become more efficient, the regions activated become smaller.
At some point, as a child progresses from decoding to fluent reading, the route of signals through her brain shifts. Instead of passing along a “dorsal route” through occipital, temporal, and parietal regions in both hemispheres, reading starts to move along a faster and more efficient “ventral route,” which is confined to the left hemisphere. With the gain in time and the freed-up brainpower, Wolf suggests, a fluent reader is able to integrate more of her own thoughts and feelings into her experience. “The secret at the heart of reading,” Wolf writes, is “the time it frees for the brain to have thoughts deeper than those that came before.” Imaging studies suggest that in many cases of dyslexia the right hemisphere never disengages, and reading remains effortful…. When reading goes well, Wolf suggests, it feels effortless, like drifting down a river rather than rowing up it. It makes you smarter because it leaves more of your brain alone.
Second, this sounds pretty similar to what Andy Clark describes in Natural-Born Cyborgs, and Tallis in The Hand: a process wherein neural plasticity and technology work to create a human-textual (or human-alphabetic) symbiosis. It's no coincidence that Dehaene titled his 2003 article "Natural-born readers."