For the first time, educators have the tools to help the majority of children with dyslexia learn to read at average levels or even above. This achievement is the product of a body of research that began with a failed attempt to build a new technology. Shortly after World War II, a team of researchers tried to build a machine that would scan print and read it to the blind. After two decades of research, they learned that human speech was far too complex for the technology of the time to duplicate. At best, the machine could reproduce words at about a tenth the rate of normal speech, impossibly slow for normal reading.
However, along the way, the researchers discovered that the words we speak are made up of individual elements of sound woven together so seamlessly that our technology cannot measure them. The word “bag,” for example, consists of three elemental speech units, represented as bbb, aaa, and ggg. An oscilloscope–a device for measuring sound–can detect only a single burst of sound when “bag” is spoken. In all, 40 elemental speech units, known as phonemes, provide the basis of the English language. Unconsciously and automatically, the brain strings phonemes together to produce hundreds of thousands of words.
With NICHD funding, the researchers soon discovered that the ability to identify the phonemes in words was not an automatic process. Rather, this ability, which they called “phonemic awareness,” needed to be taught. By themid-1970s, the researchers had learned that as children progressed through the early grades, their ability to identify the phonemes in words increased. By the early 1980s, other NICHD-funded researchers had confirmed that kindergarten children who lacked phonemic awareness were more likely to have difficulty reading in the later grades. Further studies found that simple tests of children’s ability to manipulate phonemes could predict later reading failure. Conversely, still other studies found that simple techniques to show children how to identify the phonemes in words brought about improvements in reading.
Developing children’s phonemic awareness skills appeared to prepare them to master the next step necessary in learning to read, phonics. This involves matching phonemes to the letters of the alphabet that represent them. Readers skilled in phonics can make sense of words they haven’t seen before, without first having to memorize them.
In the 1990s, NICHD-funded researchers at Yale University used new brain imaging technology to identify the three brain regions that control reading. The technique, known as functional magnetic resonance imaging, allows researchers to track activity in the brain. The researchers found that reading tends to take place in the brain’s left half, or hemisphere. Within the hemisphere, reading is controlled by three discrete brain regions working together. In the left front of the brain, one area processes phonemes. Farther back, another brain area “maps” phonemes to the letters that represent them. Still another brain area serves as a kind of long-term storage system. Once the word is learned, this brain region recognizes it automatically, without first having to decipher it phonetically.
Brain scans have shown that as readers become more skilled, this automatic recognition center becomes more active. Poor readers, however, have difficulty accessing the automatic recognition center. Instead, they rely on the phoneme center and the mapping center to process the words they see. In poor readers, these two regions work much harder than normal. For them, recognizing words is not an automatic process. Each time these readers see a word, they must puzzle over it, as if they were seeing it for the first time. Fortunately, however, instruction in phonemic awareness, phonics, and other reading skills can activate the automatic recognition process. After undergoing such training, brain scans of people who were once poor readers begin to resemble those of good readers.
The researchers also learned that while some reading difficulties seem to result from a disruption in the brain regions controlling reading, most seem to result from environmental factors. In the majority of poor readers, the brain regions controlling reading functioned normally, but had not been activated. The researchers theorized that these readers had not learned the phonemic structure of words when they were younger, but proper instruction could help these individuals learn to read at average or above average levels.
In 1997, NICHD established the National Reading Panel to review the scientific evidence on reading and to identify the most effective ways to teach children to read. The 14-member, independent panel of experts selected evidence from roughly 100,000 reading studies published since 1966 and another 15,000 published before that time. Along with instruction in phonics and phonemic awareness, the panel outlined other effective strategies for teaching children to read. One strategy, guided oral reading, involves having children read aloud while receiving guidance from skilled readers. The other, instruction in reading comprehension strategies, consists of techniques for helping children to understand what they read.
The panel’s recommendations were incorporated in a new law seeking to improve the reading ability of American children. In December of 2001, the President signed the No Child Left Behind Act. The legislation requires states to set basic standards for local school systems, and to test students to assure they have met those standards. Under the new law, the Federal government will provide school systems with financial aid, both to improve their reading programs and provide training for teachers on how to teach reading. To qualify for funding, however, school systems must adopt curriculums based on the National Reading Panel’s findings that effective reading instruction must include a combination of phonemic awareness, phonics, fluency, comprehension, and vocabulary.