WORLD OF LEARNING: MY REVIEW OF "READING IN THE BRAIN"

READING IN THE BRAIN: THE SCIENCE AND EVOLUTION OF A HUMAN INVENTION. By Stanislas Dehaene. Viking Adult, 2009. 4oo pages.

This joins the go-to books on my shelf for anyone who cares about how we read and how we learn to do it. It's next to Maryanne Wolf's Proust and the Squid and the already-dated Understanding Dyslexia by Sally Shaywitz.

It's definitely denser matter than the other two, though, and taking it in requires effort. There were a couple of things that made the task harder than it needed to be. Since Reading in the Brain generally maintains a conversational tone and does not talk down to lay people, since it offers an intriguing and insightful theory of how and why the human brain adapted to what at first appears to be a completely artificial and arbitrary process--since, in other words, I liked it--I'll get my quibbles out of the way first.

I know scientists want to be exact and precise in their language, but for the popular audience it would be ever so helpful if, in describing where things are in the brain, directional words like anterior and dorsal could be replaced with front and upper. Especially since there are so many complicated names of parts that are needed. Appendices or footnotes could alert experts to the writer's competence.

And those part names and mapping them. It sometimes seems that every book on the human brain is filled with muddy black and white diagramming of cloudy cross-sections inconsistently viewed from a variety of angles and taken from a variety of sources.

It would be lovely if Dehaene had used clear color pictures done by one illustrator, with right and left where we usually suppose they are. After all, pictures are intended to make things more understandable. Here, I often became more confused.

OK, I've got that off my chest. Dehaene can be funny, engaging and down-to-earth. He loves puns, quotes Alberto Manguel, and is a guy who says stuff like, "Literacy drastically changes the brain--literally!" He tries.

Reading in the Brain presents a far more complex model for reading than Shaywitz did. At the same time, and this is the most fascinating thing about the book, Dehaene offers a straightforward, beautifully simple hypothesis to explain why our brains can so readily connect to a complicated activity for which evolution cannot have prepared us.

The origins of writing systems--Sumerians counting bushels of grain, for example--are just a tick away on the timeline of human history. When you think about it, reading and writing for the masses have only been around for five hundred years plus. (Thank you, Mr. Gutenberg.) Our brains are hard-wired for hunting and gathering, as well as for helping each other, and for the communication needed to do so. An innate structure for deciphering alphabetic code? Impossible.

Shaywitz and others pointed out that fMRIs show an area in the left, lower, back part of the brain that successful emerging readers use, and unsuccesful readers don't. It's where the distinct individual sounds that make up syllables are broken apart and analyzed. Once that happens, we can assign symbols--little black marks called letters--to those sounds.

That processing is the key, and the reason why whole language doesn't work. To break the code we have to break the code, not absorb it by some kind of osmosis induced through immersion. How and why were our brains able to do that?

Dehaene assigns a perfectly clear name to the back area of the brain that matches articulation to signifier--the letterbox. Then he looks back through evolutionary history, and finds a comparable area in primates that is the basic assembly area for shape recognition. Not just random shapes, but the kind of shapes we see most commonly in nature, like horizontal and vertical lines, half-circles, junctions. You can see where this is going--E's and I's, t's and y's (similar to shapes found in all writing systems).

The question shouldn't be how we adapted to printed text, Dehaene says. It should be how we created a solution to a natural desire--increasing our capacity for knowledge with a tool that allowed us to record language--with the equipment we had. He coins another jargon-free term for this--neuronal recycling.

The equipment we had enabled most of us (there is growing evidence of dysfunction in the letterbox area of dyslexics) to mash together drawing and speech, and then hold onto this relationship between basic shapes and basic sounds long enough to translate a string of markings into words.

Dehaene's hypothesis leads him to all kinds of interesting stuff. For example, we are equipped to recognize objects as they turn. But it is much easier to remember an upside-down tiger than the mirror image of that tiger. Our ancestors needed to instantly identify an erect tiger whether it was coming from the right or left.

Our brains usually don't remember which side Jefferson faces on the nickel. As far as we're concerned, either way it's still a nickel. All children have to 'unlearn' this tendency to ignore reversals in order to learn to read.

On a deeper level, looking more closely at neuronal recycling might help us to better understand other cultural inventions besides literacy. Science. Math. Art. Religion. Given that brain 'structure keeps a tight rein on cultural constructions' doesn't make those constructions any less wonderful. Really, it's all the more amazing.

We are, Dehaene tells us, "a truly singular species in the cultural sphere" because we have the capability not only to learn, but "to invent and to transmit cultural objects." Those sometimes difficult transmissions make our brains struggle to cope with concepts that are not innate. That's a good reason to respect the hard work that children put into learning to read.

Those powerful inventions--like reading--are sublime in their intricacy and ingenuity. That's a good reason to read Reading in the Brain.