Brain researchers in France, Belgium, Portugal, and Brazil have been working on the puzzle of how the human brain re-purposes itself to enable us to read. The mystery is that reading 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.
The international team of neuroscientists, led by Stanislas Dehaene at the Institut National de la Santé et de la Recherche Médicale in Gif-sur-Yvette, France, reports its work in a recent issue of the journal Science, in “How Learning to Read Changes the Cortial Networks for Vision and Language.”
I grant myself the license of an academic blogger to mention this. I am an anthropologist and some members of my profession indeed possess the expertise to read material like this with deep understanding—but I am not among them. I am rather, a member of the American Association for the Advancement of Science who pages through the issues of Science and dips into the daily news alerts humbled at every turn by the vast expanse of my ignorance. Still, I keep reading. Even though I don’t understand the details, I like being a witness. And scientific reports often seem like a glimpse of something bigger.
Professor Dehaene has a talent for finding interesting problems and coming up with intriguing evidence. He has published work on how the human brain manages mathematics, which would seem to be an even more implausible re-purposing of the cerebral equipment given to us by our species’ long stay in the world of hunting and foraging.
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.
But I’ll offer an anthropological hunch that the answer is yes. And as this is a blog and I bear no responsibility for wild scientific hypotheses, I’ll go further. Anthropologists who have worked with non-literate people often reported what seem levels of observational ability that would be highly unusual in the West. This usually gets explained as a matter of culture: if you grow up in a culture where making fine discriminations about something is a condition of success, naturally you get good at it. Think of hunters tracking game or sailors “reading” the ocean. But it may well be that a brain that hasn’t been partly usurped by learning to read has a much better shot at getting good at a variety of tasks that involve special kinds of recognizing.
There is also strong evidence of evolutionary co-development of fine motor control over the hands, visual control, and the parts of the brain involved in language. Some evidence points to hand sign language as our first language. Rudimentary signing emerges spontaneously in most children, for example, before they can speak. And our right or left handedness corresponds with the brain localization of language. All of this is reason to wonder whether literacy poses some other not-yet-recognized taxes on dexterity and coordination.
Be that as it may, Dehaene has reminded us of the wonderful strangeness of literacy. Learning to read enables us to connect with the dead and with generations to come, to obliterate social and physical distance, to stop speech in its tracks and think, to experience worlds we will never see. But that enormous liberation just might come at a price paid in subtle diminishments to our direct experience of the world. We academics of course treat literacy as all gain and no loss. If we are wrong about that will it make a difference in how we view education?
6 Responses to Wired to Read
22228715 - November 25, 2010 at 8:51 am
Interesting. A trade-off does make some sense, although the impact can’t be that big if it took us thousands of years and brain scan technology to find some evidence of it. As a reader, I don’t worry so much about face recognition (maybe name-learning!) But because I do generally believe that most choices involve trade-offs, I do at times wonder whether what it would be like to NOT read, to have more quiet in my head and to focus on other humans and my physical environment as my primary source of information. When traveling abroad in a country where the language was pretty different from English (and I had virtually no skill with it), after a couple weeks I found myself ceasing to passively soak in the thousands of signs, headlines, overheard conversations, an other verbal information bits. My world was a lot quieter, and I remember thinking that the whole world looked crisper and of more saturated hues. When I returned home and went almost immediately to the grocery store with my airport ride, the written word overload was almost painful.
juliekane - November 29, 2010 at 10:50 am
My article “Poetry as Right-Hemispheric Language,” published in the peer-reviewed Journal of Consciousness Studies 11:5-6 (2004) and then reprinted in Norman Holland’s online journal PsyArt in 2007, examines a number of studies showing that illiterate children do not exhibit the same right-ear advantage for spoken language that literate children do, and that illiterate adults who suffer left-hemispheric brain lesions tend not to suffer the same linguistic impairments as do literate adults with similar lesions, and puts forth the hypothesis that phonetic alphabetic print literacy restructures the brain for language. The article can be found easily by googling.
sfgold55 - November 29, 2010 at 1:48 pm
It seems like one experiment would be to teach illiterate people to read and see if they develop cognitive deficits in other areas. (Recruiting should be easy: There are plenty of illiterate Americans who want to learn to read.)
But also, learning any skill develops one part of the brain. In his au tobiography, neurologist Eric Kandel cites research showing that in violinists, the parts of the brain that control each finger are larger than in other people. Do they experience other cognitive deficits as a result? He doesn’t say.
But it seems to me that non-literate people’s keen observational skills aren’t due to the fact that they don’t read. They;re due to the fact that they train themselves from an early age in those skills and thus develop the parts of the brain related to visual, aural and other forms of alertness to the outside world. We readers are much more internally focused.
anitao - November 29, 2010 at 2:28 pm
Does the definition of reading only include the printed word? When someone is making sense of their world..gathering information through whatever sense…isn’t that reading?
jffoster - November 30, 2010 at 4:34 pm
In answer to _anitao_ (just above), no, it isn’t reading unless you use the term metaphorically to mean ‘gather information’. But that meaning of ‘read’ then would be so broad as to be useless.
Reading is, well, reading writing. I.e. decoding writing. And there was no reading until there was writing. So what then is writing?
Writing is a graphic, tactile, or visual or even audial system in which a visual or tactile symbol represents some unit of (a) language. In logographic systems such as Chinese writing or the kanji of Japanese, the unit of the language represented is for Chinces the word and for Japanese a noun or a verb root.
There are two phonologically based kinds of writing. In the syllabic system, as used for instance by Cherokee and the kana of Japanese, a written (or other extralinguistic) symbol represents a syllable, a phonological unit. In an alphabetic type of system, in the ideal case a single graphic symbol represents a single “sound” or phonological segment.
So reading is not simply one more case of “gathering information”. Again, talk of “reading the weather” or of “reading the stream” or the woods are metaphorical uses and should not mislead us. Reading is a specific kind of decoding of a specific phenomenon — units of language.
Intesting, while logographic systems have been invented several times independently and syllabic systems have also, alphabetic writing, so far as we know (and with the possible exception of Korean hamgul) have been invented by human cultures only once. And yet all languages can be represented alphabetically.
BTW phrases such as “the printed /written word” or “the spoken word” are also somewhat metaphorical and literary. In fact there may be languages (Eskimoan, for instance ) which do not have words. They have _morphemes_, minimal strings of sound with an associated meaning, and they have sentences, just like English and all languages. But that there is in all languages an intermediate level of phonological analysis that we might call ‘word’ is not clear.
jffoster - November 30, 2010 at 4:38 pm
My apologies, the 1st word in my next but last paragraph above should have been ‘Interestingly, …’