Wednesday, September 9, 2015

Dyslexia is NOT a Learning Disability – It’s a Brain Disorder


Dyslexia is NOT a Learning Disability – It’s a Brain Disorder
David L. Raffle, PhD
Director, Raffle Brain Institute

Dyslexia, Latin for “faulty reading,” is found in over 30 million adults in the U.S., and in about 80% of children who are in special education under the category of “specific learning disability.” Dyslexia is also common in many children with attention-deficit/hyperactivity disorder (ADHD). A simple “diagnosis” of dyslexia does not offer any clues about causes or treatment, because many processes are involved in decoding, understanding, and deriving meaning from ink blots on a page. By knowing where these processes break down, a program of cognitive rehabilitation can be developed – the Raffle Reading Program.
Many young people have developmental dyslexia (seen when one first learns to read), which can result from impairment in a variety of brain regions and the connections between them (called data “streams”). Dyslexia also occurs following traumatic brain injury, late effects of cancer chemotherapy and radiation, oxygen deprivation (e.g., carbon monoxide exposure or near-drowning), various diseases (e.g., encephalitis), and a host of other causes, each of which may involve different areas of the brain.

English is a complicated language to learn, with 44 different spoken sounds (called “phonemes”) and over 200 different ways to write the sounds (called “graphemes” – for example, the “F” sound is heard in ‘fun’, ‘puff’, ‘phone’, ‘rough’, and ‘Pfeiffer”). Italian, on the other hand, has only 25 phonemes and 33 graphemes (yes, there are far fewer Italian dyslexics). Normally, word meaning is derived through visual orthography (sight-word reading) or by phonological processing (decoding words through sounds of letters and letter combinations). However, the reader must also derive meaning from words based on:
  • Various pronunciations of the same ending (‘rough’ vs. ‘dough’ vs. ‘bough’ vs. ‘cough’)
  • Inflection (“I object!” vs. “I have an object”)
  • Parts of speech (the verb “he leaves” vs. the noun “the leaves”)
  • Context of the sentence (“surf” the ocean vs. the Internet)
  • Context of the paragraph (“free shot” in basketball vs. in a bar)
  • And the countless words that come from languages all over the world (‘gesundheit’, ‘karaoke’, ‘chutzpah’, ‘burrito’, ‘ballet’, etc.).

Areas of the Brain and Dyslexia

The reading process occurs from the moment light from a page enters the eye or the sound of a word enters the ear (creating “information packets”), through various regions of the brain, and finally to the higher processing areas of cerebral cortex. Impairment anywhere along these pathways will prevent an individual from deriving meaning from words on a page. Based on examining where along these pathways the signals are blocked or distorted, an individualized program of reading rehabilitation, called the Raffle Reading Program, teaches the brain to “repair” the damage or “rewire” around it so that the process of reading will move forward as intended.

The Eye, the Optic Nerve, and the Visual Cortex

The first stop in the visual information packet’s journey is through the eye, and of course problems with vision can affect reading, including myopia (near-sightedness), hyperopia (far-sightedness), amblyopia (“lazy” eye), astigmatism (improperly curved cornea), strabismus (crossed or turned eye), nystagmus (uncontrollable eye movements), and many other eye disorders. The visual information packet enters the optic nerve of each eye, with information in the right visual field traveling to the left side of the brain and vice-versa. Problems in these areas result in visual neglect, where either the left or right side of the page can be seen but not processed, so from the reader’s point of view these areas are not there.

The visual information packet travels through a way-station (the lateral geniculate nucleus) to the visual cortex, where “perception” of the word takes place. The information packet is then sent through two separate “streams” – the ventral stream to the temporal cortex, where the form of the word is recognized, and the dorsal stream to the parietal cortex, which controls the eye movements (called saccades) that examine letters and parts of words and their relationship with surrounding letters and words. Only about 4 letters can be seen at any one eye fixation, so the eyes make constant and rapid “jumps” (each about a quarter to a half a second in length), especially when reading long and unfamiliar words.

The temporal cortex is involved in deriving meaning from the many visual information packets that enter from the ventral stream, connecting the words to visual images of words that have already been entered into the person’s memory by the hippocampus. New words are connected and associated with the meanings derived from words learned in the past, and also examined in context with other words in a sentence, forming meaning and creating learning.

Problems in any area of the brain from the eye to both the temporal and parietal lobes lead to what are called visual processing deficits. In what is often called “surface dyslexia,” the individual has trouble processing the visual appearance of a word, but would understand the word if it were heard.  Because the parietal lobe focuses on the shapes of letters and words and their location in relation to each other, individuals with dyslexia often have difficulty seeing the left side of a word (saying “then” when reading “when”), or the right side of a word (not seeing /s/ or /ed/ endings).  Some also have problems visualizing the left or right sides of individual letters, leading to reversals of letters /b/ and /d/, and letters /p/ and q/.

Most individuals with dyslexia have an underused posterior parietal cortex in the right side of their brains, causing visual problems with the left side of their vision. When they open a book, they usually look at the right page first, while individuals without dyslexia normally focus on the left side. This left-sided neglect applies specifically to word reading - they will say “hen” or “then” when reading ‘when’, or say “is” when reading ‘his’. This problem is made worse in schools, because current reading instruction follows the onset-and-rime method of reading words; for example, in the word cat, /c/ is the “onset” and /at/ is the “rime.” By forcing students to focus their attention to the right side of the word, current teaching methods worsen the impairment of a child with dyslexia. The onset-and-rime method is not used anywhere in the world in any other language, where the basis of every phoneme is a vowel alone, or a consonant followed by a vowel (e.g., /ba/, /po/, /mu/, etc.).

One simple test that Raffle Brain Institute uses to identify dyslexia is the Clock Drawing Test (Eden, Wood, and Stein, 2003). The individual is asked draw a round analog clock and write the numbers, and many (but not all) individuals with dyslexia will draw most of the numbers on the right side of the clock. What separates them from those with true right parietal damage is that, as they begin run out of numbers, they become confused or even distressed as they realize that something doesn’t look quite right…

The Ear, the Auditory Nerve, and the Auditory Cortex

The first stop in the auditory information packet’s journey is through the ear, so problems with hearing (deafness) can also affect reading. The information packets from hearing words (called phonemes) causes vibration of the bones in the ear, which sends signals through the cochlea to the auditory nerve, with low-frequency problems affecting the hearing of certain vowel and consonant sounds (a, o, u, v, m, n, etc.), and high-frequency problems affecting others (e, i, s, sh, t, th, etc.). Most of the information sent through the auditory nerves of both ears travel to the auditory cortex in the left temporal lobe of the brain, in a region called Wernicke's area, where these phonemes are compared to the many words that have been heard and memorized in the past, and also examined based on their context with other words, until meaning is derived.

Problems in any area of the brain from the ear to Wernicke’s area in the temporal lobe are called auditory processing deficits, beyond the workings of the ear examined in a normal hearing test – leading to the common phrase in schools, “There’s nothing wrong with his hearing.” However, while the hearing is fine, the processing of sounds is impaired. Many individuals have difficulty hearing the difference between letter sounds, such as between a short /e/ and short /i/, making it difficult to compare with learned words to form meaning.

Say a person is asked to travel to Tokyo, get up in front of a large group of people, and read from a Japanese novel that is transliterated into English (“hing”, “lee”  “bao”, etc.). At the end, a tearful audience breaks out in huge applause, congratulating him on “reading beautifully,” even though he did not understand a single word of it. Of course, we would agree that he did not actually read the novel, as he derived no meaning from the words. Just as the person reading the Japanese novel makes no attempt to understand the words, a person with dyslexia usually avoids the effort necessary to derive meaning from the words on the page, referred to as “word calling,” resulting in limited comprehension.

The Frontal Lobe, the Mouth, and Reading Aloud

When a person is asked to read aloud, visual information packets (words) travel to a region called Broca’s area in the right frontal lobe, where they are converted into the motor movements of the mouth and tongue to produce spoken language. Individuals with left frontal lobe impairment are said to have phonological dyslexia, having difficulty identifying individual phonemes (speech sounds) when sounding out words. Many have problems in placing their tongue or lips while reading, leading to problems reading and speaking /r/ vs. /w/ sounds, or /f/ vs. /th/ sounds.

The Raffle Reading Program: A Proven “Cure” for Dyslexia
The key to success in managing dyslexia is understanding that it is an impairment in brain functioning, not a learning disability. Specialists at Raffle Brain Institute in Los Angeles perform a neuropsychoeducational evaluation, which helps to identify specific areas of brain impairment that results in reading problems. From the information obtained, a program of specific cognitive rehabilitation techniques, called the Raffle Reading Program, is tailored to the individual needs of the child, adolescent, or adult with dyslexia. The program focuses not only on overall skills in reading decoding and comprehension, but on repairing the deficits caused by the various areas of brain impairment. The results of the Raffle Reading Program have been proven in hundreds of children who had been told by their teachers, doctors, psychologists, rehabilitation specialists, and others that that they would never be able to read, and they are now reading far better than their peers.

For more information contact Dr. Raffle at (800) 450-9799 or info@rafflebraininstitute.com. You can also visit www.rafflebraininstitute.com.

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