Overcoming Dyslexia. A new and complete science-based program for reading problems at any level. Sally Shaywitz, Yale Center for the Study of Learning and Attention. (also, Haskins Laboratories) 2005
Condensed by Charles Arthur
Chapter 3, The Big Picture. Models of Reading and Reading Disability, pgs. 27-29
Evidence from the Connecticut study, as well as from Britain and New Zealand, provides a picture of an unbroken continuum of reading ability and reading disability, a conceptualization referred to as a dimensional model, (rather than a categorical model) by researchers.
In truth, the need to refer to disorders, even those that occur along a continuum, by a specific diagnostic label often obscures the fact that many, if not most, disorders in nature occur in gradations and thus conform to a dimensional rather than a categorical model.
Chapter 4. Why Some Smart People Can’t Read.
A Model for Dyslexia pg. 40 Dyslexia does not reflect an overall defect in language but, rather, a localized weakness within a specific component of the language system: the phonological module. The phonologic module is the language factory, the functional part of the brain where the sounds of language are put together to form words and where words are broken down into their elemental sounds. (called phonemes) (This model) is based on phonological processing – processing the distinctive sounds of language. We and other dyslexia researchers have found that the phonological model provides a cogent explanation as to why some very smart people have trouble learning to read.
How is language processed in the brain? Think of the language system as a graded series of modules or components, each devoted to a particular aspect of language. The operations within the system are rapid and automatic, and we are unaware of them. They are also mandatory.
Scientists have been able to pinpoint the precise location of the glitch within the language system. At the upper levels of the language hierarchy are components involved with, for example, semantics (vocabulary or word meaning), syntax (grammatical structure), and discourse (connected sentences). At the lowest level of the hierarchy is the phonologic module, which is dedicated to processing the distinctive sound elements of language. Dyslexia involves a weakness within the language system, specifically at the level of the phonological module.
(In hearing words), before they can be identified, understood, stored in memory, or retrieved from it, they must first be broken down into phonemes by the neural machinery of the brain. …. Words must be broken down into their underlying phonemes before they can be processed by the language system. Language is a code, and the only code that can be recognized by the language system and activate its machinery is the phonologic code.
This is critical for both speaking and reading. (as well as listening). In the speech of children with dyslexia, the phonemes are less well developed. (In speaking they may confuse the word ocean with lotion, or emeny with enemy, or humidity with humanity, or reception with recession. In each case, the speaker knows what they mean, but the sounds get mixed up.
(In reading, the representatives of the phonemes (letters) are all lined up correctly on the page.) While most of us can detect the underlying sounds or phonemes in a word – for example k, aaa, and t in cat – children who are dyslexic perceive a word as an amorphous blur, without an appreciation of its underlying segmental nature. They fail to appreciate the internal sound structure of words. ….. Overall, the child must come to know that the letters he sees on the page represent, or map onto, the sounds he hears when the same word is spoken. …. He must master the alphabetic principle. (see page 44)
Chapter 5, Everyone Speaks, but not everyone Reads. (pg. 45) Why should developing an awareness that spoken words are made of smaller segments – phonemes – present such a formidable challenge? As you will learn, the answer lies with the very same mechanism that makes speaking so easy.
Linguists Noam Chomsky and Steven Pinker: spoken language is innate, instinctive. It does not have to be taught.
Through neural circuitry deep within our brains, a genetically determined phonological module automatically assembles the phonemes into words for the speaker and disassembles the spoken word back into its underlying phonemes for the listener. Thus spoken language, which takes place at a preconscious level, is effortless. …. If a baby is neurologically healthy, there is almost no way she can avoid learning to speak.
The Particulate Principle Phonemes come together to form words. By using a small number of phonemes (44 in English), a speaker has the ability to create a seemingly infinite number of words and then sentences and paragraphs. (In so doing), the phonemes don’t change; they maintain their original identity. This means that they are able to combine with each other to form entirely new and larger units, (without being changed in the process). (This makes it possible) to form an indefinite number of words, limited only by the number of combinations. As phonemes combine to form words, and words join together to form phrases and sentences, a larger and entirely new structure is created at each succeeding level of the hierarchy.
A speaker can generate phonemes very quickly, with rates averaging ten to fifteen phonemes per second. A listener has to receive the phonemes at a sufficiently fast pace so that several can be held in short-term memory at the same time and integrated to form the intended words and phrases. Phonemes can be held in the temporary memory storage bin only one or two seconds, or about five to seven unrelated words, before each, like a bubble, vanishes.
Evolution has solved this problem through co-articulation: the ability to overlap several phonemes – while maintaining the integrity of each – into one bubble or sound. As a result of co-articulation, bursts of sounds come at a pace compatible with the auditory system’s capacity to process them, and the phonemes arrive at a rapid enough pace to meet the constraints of the short-term memory system.
(There is a critical difference) in the entire process between sounds – the sounds of language and the sounds of noise – and the innate ability of the phonological module to distinguish speech from non- speech sounds. Once a sound is safely past the hearing machinery, (the ears), the language system takes over, immediately recognizing the phonemes as particles of language and processing them accordingly. Here, the language system is different from other systems, such as vision and hearing. (Sounds in words travel past the ear) into the safe haven of cerebral neural circuits specialized for receiving language. The phonologic module in the brain immediately activates and recovers the phonemes contained within each pulse (word or syllable), and automatically translates the sound into particles of language. The listener receives the exact message sent by the speaker.
(comment: the stimuli coming into the brain from the eyes do not have the same innate connections to language as the stimuli coming into the brain from the ears. Any connections that visual stimuli must gain to the automatic language system that we are born with must be as a result of learning. Thus, learning to read is more difficult than speaking so that in reading letters can be processed the same as phonemes in speech.)
Reading is More Difficult Than Speaking (pg. 49) The effortless and seamless nature of spoken language has everything to do with why reading is so hard for dyslexic children. … Speaking is natural, and reading is not. …. Reading is an acquired activity, an invention of man that must be learned at a conscious level. … While reading, too, relies on the phonologic code, the key to unraveling it is not so readily apparent (or easily available) and can only be accessed with effort on the part of the beginning reader.
Reading is not built into our genes; there is no reading module wired into the human brain. In order to read, man has to take advantage of what nature has provided: a biological module for language. For the object of the reader’s attention (print) to gain entry into the language module, a truly extraordinary transformation must occur. The reader must somehow convert the print on a page into a linguistic code – the phonetic code, the only code recognized and accepted by the language system. However, unlike the particles of spoken language, the letters of the alphabet have no inherent linguistic connotation. Unless the reader-to-be can convert the printed characters on the page into the phonetic code, these letters remain just a bunch of lines and circles totally devoid of linguistic meaning. Linguist Leonard Bloomfield: “Writing is not language, but merely a way of recording language by visible marks.” …. They stand as surrogates for speech or, to be more exact, for the sounds of speech.
Beginning readers must learn how to convert an array of meaningless symbols on paper so that they are accepted by a powerful language machinery that recognizes only the phonologic code. … The most eloquent of written prose is rendered meaningless if it cannot be transformed into the phonetic code recognized by that reader’s language module.
Breaking the Code (pg. 51) Once a child becomes aware of the segmental nature of spoken language, he has the basic elements – the particles of spoken language, phonemes, and their sounds – to which he can now attach the meaningless marks on paper but, like Cinderella, have been transformed into something truly spectacular: language. Translated into the phonetic code, printed words are now accepted by the neural circuitry already in place for processing spoken language. Decoded into phonemes, words are processed automatically by the language system. The reading code is deciphered. …. It is these very same phonemes to which the letters of the alphabet must attach if the written word is to be brought into the language system. All readers – dyslexic readers included – must take the same steps. The difference is simply in the effort involved and the time it takes to master the alphabetic principle.
Of course, children very greatly in their ease of developing phonemic awareness. …. In dyslexic children, a glitch within the language system – at the level of the phonologic module – impairs the child’s phonemic awareness and, thus, his ability to segment the spoken word into its underlying sounds. The phonemes are less sharply defined. As a result of this weakness, children have difficulty breaking the reading code.
A phonological weakness at the lowest level of the language system impairs decoding. At the same time, all the cognitive equipment, the higher-order intellectual abilities necessary for comprehension – vocabulary, syntax, discourse (understanding connected text), and reasoning - are intact. Luckily, we can now effectively treat a phonological weakness; while, ironically, the complex reasoning and sophisticated thinking skills that dyslexic children often possess are almost impossible to teach. (My husband theorizes that since the basic circuitry for linking letters to sounds is disrupted in dyslexic readers, they develop and come to rely on other neural systems, not only for reading, but for problem solving as well. )…The basic weakness in what is essentially a lower-level language function blocks access to higher-order language processes and to gaining from text. It is best when such a child can listen to a story because he can use all his higher-level thinking skills to follow the narrative and answer questions about it. (even then, weaknesses in phonological memory limit oral learning as well.)
The impact of the phonologic weakness is most obvious in reading, but it can also affect speech in other predictable ways. Robert B. Katz has documented the problems that poor readers have in naming objects shown in pictures. Errors in naming tend to share phonologic characteristics with the correct response: misnaming is not a result of a lack of knowledge but of confusing the sounds of language, like confusing volcano with tornado.
(Children with dyslexia often) use the “big picture” of theories, models, and ideas as a framework to help them remember specific details. …. Rote memorization and rapid word retrieval are particularly difficult for children with dyslexia. (They often) cannot simply memorize or do things by rote; they must get far underneath the concept and understand it at a fundamental level. This need often leads to a deeper understanding and a perspective that is different from what is achieved by some for whom things come easier because they just cannot memorize and repeat – without ever having to deeply and thoroughly understand.
Even when the dyslexic knows the information, the need to rapidly retrieve and orally present such information often results in the retrieval of a related phoneme, such as in substituting humanity for humidity. As a result, the dyslexic may appear much less capable then he or she really is. On the other hand, given time and when not pressured to provide instant oral responses, the dyslexic can deliver an excellent oral presentation.
Reading and phonemic awareness (or ability) are mutually reinforcing. Phonemic awareness (abilities) is necessary for reading, and reading, in turn, improves phonemic awareness (ability) still further. (The reading process, that is, the alphabetic principle, brings increased clarity and prominence to the phonemes.)
In the next two chapters, you will learn about the neural underpinnings of dyslexia and actually see – through brain activation patterns – what goes wrong.
Chapter 6, pgs. 59-70, Reading the Brain (Overcoming Dyslexia, by Sally Shaywitz)
(In 1861 the Frenchman Paul Broca located the area of the brain that controls and operates speech, expressive oral language, in the left frontal region now referred to as Broca’s area. A loss of function in this area results in the loss of the ability to articulate words. Shortly after, the German neurologist Carl Wernicke located the area that controlls receptive language, the ability to understand oral language. This area is along the upper part of the temporal lobe on the same left side of the brain.)
In order to read we must enter the language system; at a neural level this means that reading relies on the brain circuits already in place for language. (However, locating the sites that control language) is not quite the same as mapping out the neural machinery responsible for language.
The enormous complexity of the brain in its initial development presents a myriad of opportunities for a misconnection or a false connection. …. Most likely as a result of a genetically programmed error, the neural system necessary for phonologic analysis is somehow miswired, and a child is left with a phonologic impairment that interferes with spoken and written language. Depending on the nature or severity of this fault in the wiring, we would expect to observe variations and varying degrees of reading difficulty. What is really needed to understand dyslexia is the ability to map the full neural circuitry for reading.
(This was eventually accomplished in the 1980’s and 90’s by the newest technology) functional magnetic resonance imaging (fMRI), which allows neuroscientists to visualize the inner workings of the human brain in a completely noninvasive way; there is no radiation or injections. Basically, they provide evidence that, within the brain, local blood supply varies in response to functional activity in that region. “the blood supply of any part of the cerebral tissue is varied in accordance with the activity of the chemical changes which underlie the functional activity of that part.” (This was a principle established a century ago by the British scientists C. S. Roy and C. S. Sherrington. More recently, it has been shown) that it is the changes in energy metabolism that directly influence alterations in blood flow. (blood flow brings added fuel (oxygen) and nutrient to that location)…. This principle, together with the fact that increased blood produces alterations in the magnetic properties of blood, is what allows fMRI to work.
Chapter 7, pgs. 71-89, The Working Brain Reads
Classically, the left side of the brain has been associated with language.
Our functional imaging studies are focused on mapping the neural circuitry for reading. In planning our research, our first goal was to identify the neural pathways for breaking words into their underlying sounds. (The) specific neural sites for sounding out words was in the inferior frontal gyrus, (left side, towards the front, similar to Broca’s area) and was also involved in reading. (see diagram).
(at this point in the book, it is almost impossible to leave anything out in order to condense the description)
Pg. 78. First, the neural systems for reading in children and adults are rapidly being mapped out. Imaging studies have identified at least two neural pathways for reading; one for beginning reading for slowly sounding out words, and another that is a speedier pathway for skilled reading. Next, careful examination of brain activation patterns has revealed a glitch in this circuitry in dyslexic readers. Studies from around the world leave no doubt that dyslexic readers use different brain pathways than do good readers.
As they read, good readers activate highly interconnected neural systems that encompass regions in the back and front of the left side of the brain. (see diagram) Not surprisingly, the reading circuitry includes brain regions dedicated to processing the visual features, that is, the lines and curves that make up letters, and the transforming the letters into the sounds of language and to getting to the meaning of words.
Most of the reading part of the brain is in the back. Called the posterior reading system, as noted above, it is made up of two different pathways for reading words, one sitting somewhat higher in the brain then the other. The upper pathway is located primarily in the middle of the brain (technically, the parieto-temporal region), just above and slightly behind the ear. The lower path runs closer to the bottom of the brain (called the occipito-temporal area).
These two subsystems have different roles in reading, and their functions make sense in light of the changing needs of the reader: Beginning readers must first analyze a word; skilled readers identify a word instantaneously. The parieto-temporal (upper pathway) system works for the novice reader. Slow and analytic, it function seems to be in the early stages of learning to read, that is, in initially analyzing a word, pulling it apart, and linking its letters to their sounds.
In contrast to the step-by-step parieto-temporal system, the occipito-temporal (lower pathway) is the express pathway to reading and is the one used by skilled readers. The more skilled the reader, the more she activates this region. It responds very rapidly – in less than 150 milliseconds (less than a heartbeat) to seeing a word; instead of analyzing a word, the occipito-temporal area reacts almost instantly to the whole word as a pattern. One brief glance and the word is automatically identified on sight. It is referred to as the word form area or system.
Here’s how we think the word form system works: After a child has analyzed and correctly read a word several times, he forms an exact neural model of that specific word; the model (word form), reflecting the word’s spelling, its pronunciation, and its meaning, is now permanently stored in the occipito-temporal system. Subsequently, just seeing the word in print immediately activates the word form and all the relevant information about that word. It all happens automatically, without conscious thought or effort. As skilled readers speed through the text, the word form area is in full gear, instantly recognizing one word after another. … Thus, there is a strong link between reading skill and reliance on the word form area.
A third reading pathway, this one in Broca’s area in the front of the brain, also helps in slowly analyzing a word. There are therefore three neural pathways for reading: two slower analytic ones, the parieto-temporal and frontal, that are used mainly by beginning readers, and an express route, the occipito-temporal, relied on by experienced, skilled readers.
(The uncovering of the reading process has led) to understanding the nature of the difficulty in dyslexic readers. As mentioned earlier, imaging studies revealed markedly different brain activation patterns in dyslexic readers compared to those in good readers. As they read, good readers activate the back of the brain and also, to some extent, the front of the brain. In contrast, dyslexic readers show a fault in the system: underactivation of neural pathways in the back of the brain. Consequently, they have initial trouble analyzing words and transforming letters into sounds, and even as they mature, they remain slow and not fluent readers.
At all ages, good readers show a consistent pattern: strong activation in the back of the brain with lesser activation in the front. In contrast, brain activations in dyslexic children appear to change with age. Imaging studies reveal that older dyslexic children show increased activation in frontal regions so that by adolescence they are demonstrating a pattern of overactivation in Broca’s region – that is, they are increasingly using these frontal regions for reading (see diagram). It is as if these struggling readers are using the systems in front of the brain to try to compensate for the disruption in the back of the brain. …. One means of compensating for a reading difficulty, for example, is to subvocalize (say the words under your breath) as you read, a process that utilizes a region in the front of the brain (Broca’s area) responsible for articulating spoken words. Under the guidance of this frontal system, a dyslexic reader can develop an awareness of the sound structure of a word by physically forming the word with his lips, tongue, and vocal cords. This process of subvocalization allows him to read, albeit more slowly than if the left posterior systems were working. ….. Even high- achieving university students with childhood histories of dyslexia, who are accurate but slow readers, continue to show this pattern.
In addition to their greater reliance on Broca’s area, dyslexics are also using other auxiliary systems for reading, ones located on the right side as well as in the front of the brain – a functioning system but, alas, not an automatic one . .. This disruption in left-posterior systems prevents rapid, automatic word recognition; the development of ancillary right side (and frontal) systems allows for accurate, albeit very slow, reading. These dyslexic readers have to rely on a “manual” rather than on an automatic system for reading.
It is thought that sophisticated behaviors such as reading originate within widely distributed neural systems, and not at individual local anatomic sites, by a symphony of neurons rather than by a single section of the orchestra. …. The brain’s reliance on patterns of connectivity may have particular relevance to the teaching of reading since within these systems patterns of neural connections are continually reinforced and strengthened as a result of repeated practice and experiences. We can then imagine that each time a six-year-old is able to associate a particular sound with a letter, the neural pathways responsible for making this linkage are further reinforced and even more deeply imprinted within her brain.
Pg. 85. One of the most exciting applications of brain imaging is just coming into use: directly evaluating the effects of specific reading interventions on the neural systems for reading. … A key question relates to whether effective reading programs are band-aids that cover up a reading problem and perhaps encourage the development of secondary manual pathways, or whether they can actually rewire or “normalize” the brain.
Can dyslexic readers develop the fast-paced word form reading system? (In a recent study), we used fMRI to study boys and girls who were struggling to learn to read and who then received a yearlong experimental reading program. The progression of changes we observed was remarkable.
Images obtained immediately after the intervention showed the tentative emergence of primary left- side systems used by good readers as well as the development of right-side secondary pathways for reading. The final set of images obtained one year after the intervention had ended was startling. Not only were the right-side auxiliary pathways much less prominent but, more important, there was further development of the primary neural systems on the left side of the brain. These activation patterns were comparable to those obtained from children who had always been good readers. We had observed brain repair. And the children improved their reading. This may explain why children who receive effective interventions early on develop into both accurate and fluent readers. … These findings provide powerful evidence that early intervention with an effective reading program leads to the development of primary, automatic reading systems and allows a child to catch up to his classmates. This is consistent with accumulating evidence that experience (such as exposure to effective reading instruction in school) drives the development of the fast-paced word form system. After more than a century of frustration, it has now been shown that the brain can be rewired and that struggling children can become skilled readers.