I Can Hear You Whisper (29 page)

“Reading is an exercise in plasticity,” says Pugh. “It's taking lots of systems in the brain that do different jobs with language, memory, attention, vision, and associative learning and turning them into these really efficient circuits that allow you to get from eye to meaning in a couple of hundred milliseconds.” Success, then, depends on the
brain's ability to connect and integrate these various areas, each of which matures on its own timetable. That's one reason why children the world over usually begin to learn to read at five or older—until that point, they are not biologically ready. One necessary change is that areas that have been wired for speech adapt to also receive visual information in the form of letters. “What reading demands in hearing children is to get away from vision and into language as quickly as possible, because ultimately you want to use the biologically specialized systems for phonology, syntax, and comprehension,” explains Pugh. “At some level your grandmother could predict that, but at another level it's profound.”

This does not diminish the importance of vision. We need vision to read print. (In blind readers of braille, similar brain processes are at work from the point at which the information—received by touch—reaches the language areas at about two hundred milliseconds.) Important work by French neuroscientist Stanislas Dehaene and cognitive psychologist Bruce McCandliss of Vanderbilt University suggests the existence of a
visual word form area—a spot toward the back of the brain in the left occipitotemporal lobe that seems to specialize in recognizing text. Dehaene calls it “the brain's letter box.”
The eyes impose constraints on reading, he points out in his book
Reading in the Brain: The New Science of How We Read
, because they can take in only a little bit of information at a time, usually up to twelve letters. Good readers, though, manage to read four hundred to five hundred words per minute. So from the first step of visual analysis, those readers are rapidly transmitting the incoming visual information to other brain areas. Each system in the brain plays a role and, in working with its neighbors, is changed by the experience. “The brain becomes multimodal and that changes everything,” says Pugh. “It's no longer auditory speech or visual. It's relational. It's combinatorial.”

Sound and vision together help determine the continuum of difficulty for learning to read in different languages. A transparent language like Italian, the easiest to learn, looks as it sounds. “Every letter maps onto a single phoneme, with virtually no exceptions,” notes Dehaene. Mandarin Chinese, the most difficult language, does not. Its thousands of characters usually transcribe whole words and must generally be memorized. Italian children can learn to read in a few months; Chinese children are still working on it well into middle school. English and French children are in the middle. They may not have to master
Mandarin, but Dehaene, who argues for transparent spelling, notes that “an immense gap between the way we write and the way we speak [in English] causes years of unnecessary suffering for our children.” If you don't believe him, consider “bow” and “bough” and “tow” and “tough.”

In any language, a brain that can read is forever altered. Proof of that came from studies of women raised in small
Portuguese villages. It was the tradition in those villages that one daughter in a family would be educated and the others would be married off without much schooling. As a result, researchers were presented with a ready-made population in which women of otherwise similar intelligence and background differed only in that one knew how to read and the other did not. In another
nonsense-word study, the women listened to progressively harder nonsense words and were asked to say back what they'd just heard. “It's called auditory shadowing,” explains Pugh. “You hear, you say. No reading. Women who were literate were better at hearing those sounds and getting them out of their mouths in the right way.” He pauses for emphasis. “Think just for a second. Literacy, which has changed the brain, actually has a benefit on speech perception.” When the researchers looked at activity in the brains of the women, they found that the literate women were using the reading circuits they had developed in order to do the task.

A second study showing something similar was done by researchers Mark Seidenberg and Michael Tanenhaus back in 1979. In a study of hearing literate adults, they played two words. The subjects had to decide if the words rhymed. If they heard a pair of words like “pie”/“tie,” they would be faster to say they rhymed than a pair like “rye”/“tie.” Why? Because “pie” and “tie” are spelled the same and “rye” and “tie” are not. Only a reader knows that.

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The promise of the new understanding of how reading works in the brain is that it might allow educators to catch problems earlier. As it is, children are often well into elementary school before they're identified as needing help.
Dennis and Victoria Molfese are hoping to change that. Both psychologists at the University of Nebraska, they have been working for years on identifying patterns in very young children's brains that predict reading problems later. As early as the 1980s, the Molfeses used EEG to measure infants' brain waves and found that a slower response to acoustic stimuli such as “ba” and “ga” correlated with stronger or weaker language skills and vocabulary size as the children got older. In 2000, Dennis Molfese published a study showing that he could use brain responses to sound in newborns to predict with 80 percent accuracy which children would struggle with reading at age eight. By the year 2011, Molfese said his predictions were up to “
about ninety-nine percent” correct.

If this is true, what can we do to change the outcome? That would be easier to answer if we knew exactly what it is that's going wrong in the processing for dyslexic readers. This is the focus of Usha Goswami at Cambridge University. “It may be that we need to think more about the kind of acoustic cues in the signal that give you information about where syllables begin and which syllables rhyme with each other,” she says. Her theory about what might be occurring is grounded in work by David Poeppel.

About ten years ago, Poeppel was wrestling with the question of exactly how we chop up what we hear in order to process it efficiently. Trying to reconcile the need to sample the world in phoneme-size chunks—the standard thinking—but also seemingly in slightly longer, syllable-size chunks, Poeppel thought perhaps it was possible to have it both ways. What if, he wondered, the mind listens to the world through two separate time windows, a fast one for phonemes of twenty to fifty milliseconds and a slower one for syllables, more on the order of one hundred fifty to three hundred milliseconds? “One way the brain proceeds is to break complicated scientific problems into many problems,” he says. He imagined essentially that as you hear the world—music or speech—your brain records two CDs, one for the left hemisphere and one for the right. But when your brain samples them, a certain asymmetry sets in: For the CD on the left, you look at more of the fast-rate information and less of the slow-rate and vice versa for the CD on the right. Then you combine the two for the fullest possible picture.

Goswami's theory is that dyslexic readers struggle in the slower time window. In particular, they have trouble discerning the sharp increase in signal intensity, the “rise time,” that accompanies the start of a new syllable. Another prominent researcher,
Anne-Lise Giraud, argues the opposite, that it may be that dyslexic readers struggle with the faster time window that governs phonemes. But either way, the general idea supports Goswami's remedies, which include nursery rhymes,
poetry, and music.

All of those suggestions are echoed by other researchers who've looked at interventions that build phonological awareness. Poetry sharpens the developing ability to hear the smallest sounds of language, argues Maryanne Wolf. Old-fashioned children's rhymes such as Mother Goose include alliteration, assonance, rhyme, and repetition, she notes, all of which help the cause. Wolf's group recently published a study showing that kindergartners who got more musical training demonstrated greater phonological awareness than those who got less. In addition, an early, well-known experiment in the United Kingdom demonstrated the power of rhyme to facilitate reading.
Lynette Bradley and Peter Bryant worked with four groups of four-year-old children. Two of the groups got special training on words that either started with the same sound (alliteration) or rhymed, and were asked to put together those that shared sounds. One of those groups was also shown a letter that matched the shared sound. When tested several years later, those who had received the rhyme training were much better at phonological awareness and learned to read more easily. If they had also seen the matching letter during training, they did best of all.

There's at least one other striking correlation between early experience and later reading success. “Learning to read begins the first time an infant is held and read a story,” wrote Wolf. “How often this happens, or fails to happen, in the first five years of childhood turns out to be one of the best predictors of later reading. . . .
As they listen to stories of Babar, Toad, and Curious George and say ‘goodnight moon' every evening, children gradually learn that the mysterious notations on the page make words, words make stories, stories teach us all manner of things that make up the known universe.”

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What if the child can't hear
Goodnight Moon
? What if, as for Alex, bedtime stories are falling on deaf ears? Given all that I had learned, it was no longer surprising that deaf and hard-of-hearing children struggled so much with reading, yet all the more worrisome when Alex's hearing got worse just as he was beginning to learn to tackle books. In addition to the inherent difficulty of acquiring phonologic awareness when you can't hear spoken language, there is the stark fact that for many decades, even centuries, deaf children did not learn
any
language until they entered school. Even today, there are a few children in this situation. I have met some.

There have really been two fundamental changes for deaf and hard-of-hearing children. One is the cochlear implant, the other the
introduction of early hearing screenings. Since 1993, the percentage of newborns being screened has risen from 3 to 95 percent. The goal today is to identify children with hearing loss by three months of age and intervene by six months. Such intervention can mean hearing aids, sign language, infant/parent speech therapy sessions in which the baby is exposed to spoken language, or all of the above. At twelve months of age, children who are good candidates can receive one or, more often these days, two cochlear implants. That is a radically different situation from the one in which children were routinely not identified as having a hearing loss until they were three or four years old; and it would seem to bode well for later reading success. Acquiring a complete first language early in childhood—any language—is critical for later reading comprehension, and a child who learns either English or ASL early will develop the same language circuits in the brain. But they do need to learn that first language well.

I also now understood that it wasn't arbitrary that mean deaf reading levels are stuck at fourth grade. That is the moment at which most children either have or have not gained fluency. Those who don't get it by then, who hit what researchers call the “fourth-grade slump,” will probably never get through the rest of the reading obstacle course.

But, intriguingly, some deaf children—without cochlear implants—
do
read well. “Now we have a massive mystery,” says
Ken Pugh, who serves as an advisor for a research center at Gallaudet. “What is phonologic awareness if you don't have sound? It's entirely possible that it still exists. Without the ear, it's going to have to be redefined in some way. Are there different ways to build a reading circuit?” For neuroscientists, educators, and parents of deaf and hard-of-hearing children, that is a fascinating and urgent question. The deaf readers themselves don't seem to know how they do it, just as skilled hearing readers might have a hard time explaining exactly what they're doing as they flip the pages of a gripping book. “One of the challenges for signers is that learning to read English is two things: It's learning to read and it's a new language,” says Pugh. Research on bilingualism that's specific to spoken and visual languages might be particularly useful. But there might be other answers as well. When I talked to him, Pugh and his colleagues at Haskins were in the process of working with ASL expert Karen Emmorey, a neuroscientist at San Diego State University, to try to secure a grant for a study that would look at the question of how successful deaf readers achieve fluency.

One possibility would be that deaf students can develop phonological awareness either through years of articulation training—so that they have experience producing phonemes, if not perceiving them—or through fingerspelling, speechreading, the phonology of ASL (handshapes, articulation, etc.), or through a combination of such strategies.
Research with students at Gallaudet some time ago did indicate that some may be using phonology in spite of the fact that they can't hear. The studies made use of a phenomenon called priming, in which the word presented first makes you faster or slower at reading the word that follows. It works even better if the prime is presented subliminally. If the target word is “tribe,” for instance, you will recognize it faster if I prime you with “bribe” rather than with “blurb.” Because English has so much irregular spelling, however, you will be fifty milliseconds slower to recognize “touch” if I prime you with “couch.” They are spelled the same, but they sound different. “None of that should matter to deaf readers and yet it does,” says Pugh. They sped up for “bribe”/“tribe” and slowed down for “couch”/ “touch”—not to the same degree as hearing readers but enough to show a measurable effect.