1 3 4 Y B Y T H E B O O K E D I S O N M I Y A W A K I My hope is that neuroscientist Stanislas Dehaene’s new book on how we read will be read widely. The main reason has to do with the way he writes, in a style free of self-congratulation, with gems to be found on random pages. Dehaene quotes from Alberto Manguel ’s History of Reading in an early chapter: ‘‘Only when the able eye makes contact with the markings on the tablet does the text come to active life. All writing depends on the generosity of the reader.’’ To which, one might append, science writing can be too ungenerous at times – a scientist, intending to be accessible and lucid, confirms only that science is distant, luster absent; the words are opaque. Readerly largesse isn’t possible, and the author has a problem that modern science can’t fix: he just can’t write well. Not so with Dehaene. Once a mathematician, later a psychologist , he has read all kinds of books and has ‘‘listened to the dead with his eyes’’ (as Francisco de Quevedo defined reading, quoted on page 1); now Dehaene studies what he calls ‘‘reading in the brain’’ at the Collège de France. His subject is of particular interest for R e a d i n g i n t h e B r a i n : T h e S c i e n c e a n d E v o l u t i o n o f a H u m a n I n v e n t i o n , by Stanislas Dehaene (Viking, 388 pp., $27.95) 1 3 5 R teachers at all levels, from earliest years to the university. How does the brain process the markings on the tablet (or, more commonly these days, on the tiny hand-held screen)? How does the brain learn to do so, and – importantly in life – when? What does science say about what Montaigne called the ‘‘insatiable, versatile, and erratic’’ nature of the mind moving among pleasures such as a good book? Let’s start with Manguel’s able eye – which is to say, with how eyes see words. Dehaene describes an important ine≈ciency or eccentricity: in the quiet of a study, reading with seeming ease and calm, the reader’s eyes jerk forward and backward at a rate of four or five tiny side glances per second, as if they were watching an intense tennis match on the page. These ‘‘saccades’’ of the eyes are necessary because the eyes must be positioned and repositioned just so. They need to focus the words on the page in a small part of the retina, where vision is clearest and the appreciation of detail most precise. At best, we acutely see only a dozen words at a time, maybe three or four to the left of a fixation point (the center of visual focus) and seven or eight to the right. For those who read Hebrew or Arabic, the asymmetry is reversed: several words to the right of the fixation point and more to the left, as these languages are read from right to left. For Asian languages, in which the complexity of an individual character is greater on average than in the West, the number of saccades per second is greater. ‘‘Reading is nothing but the word-by-word mental restitution of a text through a series of snapshots,’’ Dehaene concludes, as if to suggest that reading is the experience of a fractured photographic collage by David Hockney. Perhaps it is, by the way. Eyes can move minutely only so quickly, no matter how much we might train or condition ourselves. This has a practical implication : based on the constraint of our jerking eyes, readers of the English language who clip along at four hundred to five hundred words per minute are reading at near optimum. So, for example , if it has taken you a little over a minute to get to the present sentence, you are flirting with peak physiological e≈ciency. Dehaene suggests...