Your Brain on Books: You Are What You Read

Picture yourself as I think of you at this moment, sprawled on a beach towel with your summer reading finally beside you—the latest Nora Ephron, perhaps, or A Thousand Splendid Suns (and, of course, Tufts Magazine). You may not realize it as you shake the sand off the page and prepare to enter the world of print, but you and your brain are about to embark on a life-altering journey.

In part, the journey is an intellectual one. As the French novelist Marcel Proust observed a century ago, reading is a kind of sanctuary where human beings have access to thousands of different realities they might otherwise never encounter or understand. Each of these new realities can transform your life without your ever leaving your sandy retreat.

But the journey also has a deeply important biological dimension. Cognitive science is shedding light on how our brains reshape themselves as they learn to use the relatively recent invention known as reading. Together, these intellectual and biological processes allow us to grow as readers throughout our lives.

Let me give you an example in the form of an exercise. Below are two breath-defying sentences from Proust’s essay “On Reading.” Your job is to read them as fast as you can.

There are perhaps no days of our childhood we lived so fully as those . . . we spent with a favorite book. Everything that filled them for others, so it seemed, and that we dismissed as a vulgar obstacle to a divine pleasure: the game for which a friend would come to fetch us at the most interesting passage; the troublesome bee or sun ray that forced us to lift our eyes from the page or to change position; the provisions for the afternoon snack that we had been made to take along and that we left beside us on the bench without touching, while above our head the sun was diminishing in force in the blue sky; the dinner we had to return home for, and during which we thought only of going up immediately afterward to finish the interrupted chapter, all those things with which reading should have kept us from feeling anything but annoyance, on the contrary they have engraved in us so sweet a memory (so much more precious to our present judgment than what we read then with such love), that if we still happen today to leaf through those books of another time, it is for no other reason than that they are the only calendars we have kept of days that have vanished, and we hope to see reflected on their pages the dwellings and the ponds which no longer exist.

Consider first what you were thinking while you read this passage. If you are like me, Proust conjured up your own long-stored memories of books: the secret places you found to read, away from the intrusions of siblings and friends; the thrilling sensations elicited by Jane Austen, Charlotte Bronte, and Mark Twain; the flashlight’s beam you hoped your parents couldn’t see beneath your tent of blankets. This is Proust’s reading sanctuary, and it is ours. It is where we learned to roam through Middle Earth, Lilliput, and Narnia. It is where we first tried on the experiences of those we would never meet: princes and paupers, dragons and damsels, !Kung warriors, and a Dutch Jewish girl hiding with her family from Nazi soldiers.

While reading, we can leave our own consciousness and pass over into the consciousness of another person, another age, another culture. We can try on, identify with, and even enter for a brief time the wholly different perspective of someone else. When we pass over into how a knight thinks or how a villain can deny wrong- doing—or when, later in our reading career, we imagine ourselves harvesting Early Girl tomatoes with Barbara Kingsolver or probing the mysteries of space and time with the young Einstein—we never come back quite the same. Sometimes we’re inspired, sometimes saddened, but we are always enriched. Wherever they were set, our original boundaries are challenged, teased, and gradually placed somewhere new. An expanding sense of “other” changes who we are, and, most importantly for children, what we imagine we can be.

But now let’s go back and look at what happened on a more basic level when I asked you to switch your attention to Proust’s passage. You engaged an array of cognitive functions—everything from attention and memory to visual, auditory, and linguistic processing.

At the outset, your brain’s attentional and executive systems prepared you to read the passage speedily and still understand it. Next, your visual system raced into action, swooping across the page and forwarding its gleanings about letter shapes, word forms, and common phrases to your linguistic systems. Without a single moment of conscious awareness, you applied rules that associate specific letters with specific sounds and specific letter patterns with specific words.

Meanwhile, you also activated a battery of higher-level language and comprehension processes, and did so with a rapidity that still astounds researchers. To take one example, your semantic systems surveyed every possible meaning of each of the 233 words you read and, in every case, selected the most appropriate one, given the context. This is a far more complex operation than one might think. Years ago, the late cognitive scientist David Swinney, once a professor of psychology at Tufts, discovered that the brain doesn’t just find one simple definition for a word; instead it unearths a trove of knowledge about that word and the many related to it. That is, when we read the word bug, we think of not only the more common meaning (a crawling, six-legged creature), but also all the less frequent associations—to spies, Volkswagens, and glitches in our software.

To sort through all this knowledge, your semantic systems had to function closely with your grammatical systems, which were themselves working overtime to negotiate Proust’s unfamiliar sentence constructions, like his use of long clauses strung together by oh-so-many commas and semicolons. And to keep you from forgetting what you already read 50 words back, your semantic and grammatical systems both had to function closely with your working memory—the cognitive blackboard that stores information for use in the near term.

If what you read didn’t make sense to you, you might have reread some parts. And then, once the passage did make sense to you, you generated inferences and hypotheses, based on your own background knowledge. You arrived at an understanding of what Proust was describing: a glorious day in childhood made timeless through the “divine pleasure” that is reading.

Old Neurons, New Tricks
What makes all of this possible is the brain’s amazing plasticity. After all, we were never born to read; we have no genes that are solely for literacy. Rather, human beings invented reading, and it took them thousands of years of cognitive breakthroughs to go from simple markings called tokens to text encoded in writing systems like Sumerian, Chinese, or the Greek alphabet. Reading has expanded the ways we are able to think and altered the cultural development of our species; still, it is a wholly learned skill, one that effects deep and lasting neurological changes in the individual. And because of that, every child in every generation has to do a lot of work. As the cognitive scientist Steven Pinker has noted, “Children are wired for sound, but print is an optional accessory that must be painstakingly bolted on.”

The humans who invented reading employed what Stanislas Dehaene, the French neuroscientist, calls neuronal recycling. Their brains did several ingenious things with just three innate capacities: the capacity to form areas of specialization for recognizing patterns and objects, the capacity to make new connections among older structures, and the capacity to recruit information from the areas of specialization automatically.

The first of those, specialized pattern and object recognition, is abundantly evident in our visual system. Babies come into the world with visual circuits that are wired to ensure that each neuron in the retina corresponds to a specific set of cells in the occipital lobes of the brain. In pattern recognition, a property of our visual system known as retinotopic organization causes every line, diagonal, circle, and arc we see to activate, in a split second, a specific store of knowledge. Long ago, it was important for survival—it allowed our Cro-Magnon forebears to identify distant prey or a predator’s footprint. Object recognition has its own set of purposes. Today, it’s what enables car salesmen to identify different models of cars a quarter mile away, and bird-watchers to identify a tern the rest of us can’t even see.

The second capacity that Dehaene points out—our ability to form new connections among older structures—is what permits our brain to associate subtle visual details with sounds, like the sounds in speech. And that’s what allows us to decipher print.

The third capacity exploited by the reading brain—the capacity of neuronal circuits to become virtually automatic—comes into play only after hundreds or thousands of exposures to written language. The networks of cells that recognize letters and letter patterns and those that link such visual data with sounds and words learn to fire together. As they do, they create mental images of letters and letter patterns that seem almost insepar¬able from particular sounds and words.

Now that the brain no longer has to “look up” information in its voluminous files, reading proceeds far more rapidly. In fact, neuroscientists at Yale and Georgetown point out that as alphabetic readers go on reading, their brain typically no longer needs to use both its hemispheres to link up letters and letter patterns with sounds and words. Instead it relies on a more concentrated, efficient system that lies largely in the left hemisphere. By the time that happens, the connection between print and language requires no conscious awareness at all.

The Growth of Comprehension
These insights have an array of implications for how reading should be taught. Certainly, they underscore the importance of an enriched environment early on in life. To gain the facility with language and the visual acumen they will need, preschoolers must be read to and talked to; they must be made aware of print wherever it occurs—on street signs, on cereal boxes, and in the letters of their own names. Think of it: much of what our ancestors learned to do over the course of about 2,000 years our young children must learn to do in about 2,000 days, the brief span from birth until first grade. And for older children who do not learn to read easily because of dyslexia, our new knowledge about the intellectual and biological dimensions of reading should dispel simpleminded views of the disability and its remediation. For example, dyslexia cannot be blamed on a flaw in the brain’s “reading center,” for such a center does not exist. Learning to read, like Red Sox baseball, is a wonderful thing that can go wrong for a host of reasons. If a child cannot seem to learn to read and there is no obvious reason for it (like abnormal vision or intelligence or a lack of instruction), it is critical to have that child evaluated by reading specialists and clinicians.

But even when a child’s initiation into reading proceeds without a hitch, there is more work to be done than meets the eye. One vital truth that parents and educators can overlook is that associating letters with sounds and letter patterns with words does not equal comprehension. Moreover, children who comprehend the facts in their reading material do not always understand the varied uses of words, irony, voice, metaphor, and point of view.

Fortunately, many young readers are drawn to the literature of fantasy and magic. This proves to be an ideal milieu in which to begin moving away from a more concrete to a more abstract stage of cognitive processing. Why? Because nothing is ever quite what it seems. Reading comprehension grows exponentially as children traipsing through the worlds of Middle Earth, Narnia, and Hogwarts learn to call upon their prior knowledge, predict consequences, draw inferences, monitor gaps in their understanding, and interpret how each new clue and revelation changes what they know. As they accompany heroes who struggle to elude ring-wraiths and dragons, they start to unpeel the layers of meaning in a word, in a phrase, and in a thought. That is, they leave the surface layers of text to explore the wondrous terrain that lies beneath.

This way of delving into literature has the potential to change us at every stage of our reading lives. But it is singularly formative in the period of growing autonomy and fluent comprehension, which generally occurs in the middle grades. The young person’s task is to learn to use reading for life, both inside the classroom and out in the world.

And in fact, the fluent reading brain not only expands its ability to understand, it feels more than ever before. We see growing activation of the limbic system, the seat of our emotional life, and more connections to cognition in this system. The limbic system, located immediately below the topmost cortical layer of the brain, underlies our ability to feel pleasure, disgust, horror, and elation over what we read, and to empathize with fictional characters. It also helps us to decide which parts of what we read are most important. Our attention and comprehension processes become either stirred or inert, depending on whether what we’re reading interests us.

Of course, such developments are dependent on that third innate capacity which the brain presses into service for reading: our capacity for automatic retrieval of recognized patterns. The developmental shift that occurs as we begin to rely solely on the brain’s left hemisphere to link letters and letter patterns with sounds and words frees up areas in both hemispheres to be used for comprehension.

The child now receives the greatest gift of the evolved reading brain: time. The young fluent reader learns to integrate more metaphorical, inferential, analogical, affective, and experiential knowledge with every newly won millisecond. The brain becomes fast enough to think—really think—while engaged with the text. Nothing is more important in the act of reading. If we cannot do it, we cannot inhabit Narnia or Middle Earth or any other literary landscape.

One hundred and fifty years ago Charles Darwin saw in creation a phenomenon whereby infinite forms evolve from finite principles: “from so simple a beginning, endless forms most beautiful and most wonderful have been, and are being, evolved.” So it is with written language. Biologically and intellectually, reading allows the species to go beyond what is given. Proust said much the same thing, if more obliquely, in a powerful description of reading’s ability to elicit our own thinking.

We feel quite truly that our wisdom begins where that of the author ends, and we would like to have him give us answers, while all he can do is give us desires. And these desires he can arouse in us only by making us contemplate the supreme beauty which the last effort of his art has permitted him to reach. But by . . . a law which perhaps signifies that we can receive the truth from nobody, and that we must create it ourselves, that which is the end of their wisdom appears to us as but the beginning of ours.

One True Sentence
How our reading changes over the course of our adult lives depends largely on what we read and how we read it. “Reading is experience,” the essayist Joseph Epstein has written. “A biography of any literary person ought to deal at length with what he read and when, for in some sense, we are what we read.”

Moreover, as we mature, we bring to the text not only cognitive expertise but also the impact of life experiences—our loves, losses, joys, sorrows, successes, and failures. Our interpretive response to what we read has a life-embroidered depth that, as often as not, takes us in new directions from where the author’s thinking left us. This explains how we can read a work of literature at ages 17, 37, 57, and 77 and come away with four entirely different understandings.

My own repeated reading of George Eliot’s Middlemarch is a good example. In that novel, the beautiful young heroine Dorothea Brooke marries a much older scholar, Mr. Casaubon, primarily to help him bring his greatly ambitious literary project to fruition. During their honeymoon in Rome, Mr. Casaubon visits many libraries and Dorothea is left to her own thoughts:

How was it that in the weeks since her marriage Dorothea had not distinctly observed but felt with a stifling depression, that the large vistas and wide fresh air which she had dreamed of finding in her husband’s mind were replaced by ante-rooms and winding passages which seemed to lead nowhither?

Slowly we infer that Dorothea has seen through her aged bridegroom and now knows that Mr. Casaubon has no great unifying work, no book, nothing beneath the endless, unconnected minutiae preserved in his little white note cards. Eliot strings together four clauses and six phrases before she leaves us “nowhither.” It is almost as if she uses syntax’s recursive potential to recreate the endless anterooms that characterize Mr. Casaubon’s mind.

Then a later passage gives us the perspective of Mr. Casaubon himself:

He had formerly observed with approbation her capacity for worshipping the right object; he now foresaw with sudden terror that this capacity might be replaced with presumption—that which sees vaguely a great many fine ends and has not the least notion of what it costs to research them.

I have read Middlemarch a half dozen times. Only when I read it last year did I sense the meaning of this passage. For three decades I identified completely with the disillusionment of the idealistic Dorothea. Only now do I begin to fathom Casaubon’s fears and unmet hopes, and recognize his own form of disillusion at not being understood by Dorothea.

I never thought I would see the day when I empathized with Mr. Casaubon, but now, with no small humility, I have to admit that I do empathize with him. So also did George Eliot, perhaps for reasons similar enough to my own. Just as reading changes our lives, our lives change our reading.

If I could have what Ernest Hemingway always sought—“one true sentence”—to end my natural history of reading’s development, it would be this: The end of reading development doesn’t exist. The story of reading moves ever forward, leaving the eye, the tongue, the word, the author for a new place. And from that place the truth breaks forth anew—every time.

MARYANNE WOLF is a professor of child development and directs Tufts’ Center for Reading and Language Research. She also works with the Tufts Literacy Corps on projects in local communities. Our article is adapted from her forthcoming book, Proust and the Squid: The Story and Science of the Reading Brain (HarperCollins).