Dyslexia

views updated May 14 2018

Dyslexia

Definition

Dyslexia is a kind of learning disability noted for spatial reversals and shifts and is sometimes described as a neurological disorder. It manifests as difficulties with reading, writing, spelling and sometimes math. Occasionally, balance, movement, and rhythm are affected. Persons with dyslexia frequently display above average to superior intelligence, gifted creativity and genius. Leonardo da Vinci, Albert Einstein, Walt Disney, and the Olympic multi-Gold Medal diving champion, Greg Louganis, are noted examples of persons with dyslexia.

Description

Genetics is believed to be a deciding factor in whether or not a person develops dyslexia. The condition may appear as early as three months. One report suggested that as many as 515% of Americans are affected. The National Institute of Health (NIH) reports that up to 8% of American elementary school children may have the unique characteristics described originally in 1920 by Dr. Samuel Torrey Orton. Believing it first a condition of "cross lateralization of the brain," by which he meant that functions normally processed on the right side of the brain are processed on the left side in the person with dyslexia, Dr. Orton later modified his description of the condition as being a "mixed hemispheric dominance," by which he meant that the alteration of functions to the opposite side of the brain occurred sometimes, but not all the time.

Since the advent of Magnetic Resonance Imaging (MRIs), scientists have been able to view dyslexia from

SYMPTOMS OF DYSLEXIA
inability to associate symbols with sounds and vice versa
frequent word guessing
confusion with verbal instructions without visual cues
confused handedness
difficulty sequencing items
slow, soft spoken reading
frequent mispronounciation of words when reading
misperception of words, letters, and numbers moving or disappearing on a written page

another vantage point, ironically, a process imitating what happens inside the mind of a dyslexic individual, according to one educator with dyslexia, Ronald D. Davis. He describes the ordinary ability of the person with dyslexia to visualize an object from multiple points of view, a process which has a moving point of view and which is spatially unanchored. When presented with a word that is easily visualized as a known object, like horse, the dyslexic mind easily imagines the horse from multiple perspectives, and, so rapidlysomewhere between 400 to 2,000 times faster than those without dyslexiavisual cues are processed 'almost intuitively,' demonstrating great mastery of the objectified visual world. However, when it comes to processing sound, language, speaking, handwriting and understanding verbalized communication not associated with an object, like the words the or and, a series of non-image disconnections leads to confusion, disorientation, and an inability to adequately make sense of key pieces of visual information. To the person with dyslexia, a simple seven word sentence may look like a three word sentence with four blank spaces here and there.

Causes & symptoms

Although an exact cause has not been identified, studies have identified differences in the way sound and visual information are processed between persons with and without dyslexia. In the dyslexic individual these differences create what one NIH scientist refers to as a "physiologic signature"a unique brain patternperhaps the result of emphasized activity along dopamine related neuro-pathways. Dopamine is a neurotransmitter, a chemical substance acting in the brain that facilitates certain kinds of messages. According to one author, when dopamine levels are high, the person with dyslexia experiences time as moving very slowly outside themselves, and very fast inside. As if time stands still. This author also notes that when the person with dyslexia experiences episodes of disorientation, when words or sounds do not create a visual picture for them and their mind continues to try and solve the confusion visually, dopamine levels shift and change. This would seem to be consistent with some of the symptoms of dyslexia, such as inaccurate perceptions of time and a lot of day dreaming.

Symptoms may include:

  • poor ability to associate symbols with sounds and vice versa
  • frequent word guessing when reading, and an inability to retain meaning
  • confusion when given verbal instructions unaccompanied by visual cues
  • confused sense of spatial orientation, especially by reversing letters and numbers, and losing one's place frequently while reading, or skipping lines
  • having the perception that words, letters and numbers move around, disappear, or get bigger or smaller
  • overlooking punctuation marks or other details of language
  • slow, labored reading and speech may be difficult to understand, words often mispronounced and softly spoken
  • confused sense of right and left handedness
  • math concepts are difficult to learn, excessive daydreaming, and difficulty with time
  • difficulty sequencing items
  • difficulty with jigsaw puzzles; walking a chalk line straightly or other fine motor skill tasks.

Other more positive characteristics common with dyslexia include:

  • primary ability of the brain to alter and create perceptions
  • highly aware of their environment, intelligent, and above average curiosity
  • intuitive, insightful, and having the extraordinary ability of thinking in pictures
  • multi-dimensional perception (from various viewpoints almost simultaneously)
  • vivid imagination
  • experiencing thought as reality (confusing what they see with what they think they see), thereby being abundantly creative.

Diagnosis

Diagnosis is difficult in part because symptoms can also result from other conditions and because no two individuals display the same symptoms. As a result, dyslexia can be viewed as a developmental condition, a "self-created condition," rather than as a disease. As each individual baby interprets visual data, and adapts to the environment accordingly, developing their own individual and unique brain patterns. It is that developmental pattern that is consistent among people with dyslexia. When the individual's mind cannot make sense of the data, confusion and disorientation result; incorrect data is incorporated, causing the individual to make mistakes that leads to emotional reactions, primarily frustration. A behavior is adopted that constitutes a learning disability because it disables future learning and, ultimately, affects self esteem.

Sometimes the learning disorder of dyslexia is inaccurately paralleled to Attention Deficit Disorder (ADD) or Attention Deficit Hyperactivity Disorder (ADHD). In a 2003 study, distinguishable differences between the two learning disorders were readily apparent. Comparing 105 boys between the ages of eight and ten, from three different schools and cross divided into three different groups35 boys diagnosed with ADHD not taking stimulant medication, 35 boys with dyslexia, and 35 boys without learning disabilitiesthe study found clear and diagnostically useful differences in speech related patterns between all groups. However, since diagnosis of a learning disability may be made between parents and teacher or other school administrators on the basis of symptoms rather than clinical diagnostic testing, careful diagnosis, as always, is advisable.

Treatment

Ronald D. Davis, writing in The Gift of Dyslexia outlines an alternative and complementary treatment consistent with the "moving point of view" model. According to this model, and the reason why letters seem to change shape and float, why lines of print appear to move, and why words appear to be other than they are is that the dyslexic individual sees the world predominantly through his or her "mind's eye," rather than through his or her physiologic eye. In other words, the person with dyslexia more than all others, sees what he or she 'thinks' they see, rather than what their eyeballs see. To further complicate matters, they do this so quickly, they easily become confused when the multiple facets do not produce a solid view. The object of treatment proposed by Ronald Davis, a dyslexic individual himself, is to train the mind's eye to return to a learned, anchored, viewpoint when they realize they are seeing with their mind, and not with their eyeballs. This is accomplished with assessment testing, followed by one-on-one exercises that retrain mental perception pathways. Using the gifts of the dyslexic individualtheir imagination and curiositythese exercises involve creative physical activities, including the use of modeling clay, "koosh" balls, and movement training. Davis founded the Reading Research Council's Dyslexia Correction Center in 1982, and the Davis Dyslexia Association International, which trains educators and therapists, in 1995.

Another alternative treatment option seeks to address unmastered learning skills needed for reading and math. This system, called Audioblox, may be used one-on-one (especially for children) or in groups, and involves a series of mental exercises that address learning, focussing on the "deficits" of dyslexia. Treatment involves the purchase of a kit online that contains a book entitled The Right to Read, a supplementary manual, a computer program on CD to supplement Audioblox training, and teaching materials. The book is in two parts; first, an explanation of theory; second, the program itself, with exercises. The supplementary manual contains specialized programs for areas of deficit, including handwriting, spelling, math, pre-school readiness, and high school or adult learning. The teaching materials include 96 colored blocks, representing each of six colors on each of the six sides of the block; a view blocking screen; colored cards with preprinted patterns; letter cards; a reading book with a story written in the 800 most common English words, and word cards; and, a demonstration video. The kit originates in England; pricing in America ranges approximately between $135 and $150.

Special education recommendations include helping a child stay organized and on task by keeping their desk and workplace free of extraneous, distracting materials; making more frequent, shorter assignments to increase confidence; providing positive, "immediate gratification" feedback; and short conferences or work contracts as needed.

Allopathic treatment

Allopathic medical treatment for dyslexia includes use of anti-motion drugs, addressing the symptoms of balance and coordination which results from visual perception alterations; stimulant drugs such as Cylert or Ritalin, to address symptoms of low self esteem, restlessness, and distractibility, and 'nootropics' drugs, a class of drugs believed to improve cognitive function. The stimulant drugs may be more effective for learning disorders related to ADHD or ADD than for dyslexia. The drug Piracetam, a nootropic, although reported as a possible treatment for dyslexia, is also reported to have legal issues because it has not been approved for use in the United States by the Food and Drug Administration (FDA). Reported potential side effects of the stimulants include nervousness and insomnia , and are contra-indicated with epilepsy, allergies , blood pressure problems, or with use of monoamine oxidase (MAO) inhibitors. Long-term use of stimulants in children are reported to adversely affect growth, may ironically depress the nervous system or lead to loss of consciousness. By reducing natural levels of stimulants in the brain, they may also cause dependence. The stimulants and nootropics are said to increase the effects of alcohol and amphetamines. Other possible interactions include use of anti-convulsants or anti-epileptics; tricyclic anti-depressants; anti-coagulants, like Coumadin; and "atropine-like drugs" that blocks the neurotransmitter acetylcholine.

Prognosis

If left unaddressed, a person with dyslexia may become "functionally illiterate," able to function limited by their ability to read, spell, have their handwriting understood, or do arithmetic. Recognizing that dyslexia is a developed learning disorder affecting people of extraordinary curiosity, imagination and intelligencepeople of genius, oftenfrom a productive or functional point of view, dyslexia may contribute significantly, positively or negatively, to performance levels. From an emotional or psychological point of view, dyslexia affects self esteem, and promotes confusion and frustration, that may contribute to under achievement.

Prevention

No method of preventing dyslexia is currently known. However, existing methods of treatment may prevent or reduce the secondary or indirect losses to individuals, society and culture that might otherwise occur. As the genetic aspects of dyslexia are revealed, genetic chromosomal modifications may prevent the expression of dyslexia in future generations. Wise use of present and future understandings will allow individuals with dyslexic gifts, individuals such as Leonardo daVinci, Albert Einstein, Walt Disney and Greg Louganis, to continue to contribute their genius and talents.

Resources

BOOKS

Clayman, M.D., Charles B., ed. The American Medical Association Guide to Prescription and Over-The-Counter Drugs. New York: Random House, 1988.

Davis, Ronald D., with Edlon M. Braun. The Gift of Dyslexia, Why Some of the Smartest People Can't Read and How They Can Learn. New York: Berkley Publishing Group, 1997.

Pierangelo, Ph.D., Roger and Robert Jacoby. Parents' Complete Special Education Guide. New York: Simon Schuster, 1996.

Thomas, M.D., Clayton L., ed. Taber's Cyclopedic Medical Dictionary, 16th edition. Philadelphia: Davis Co., 1989.

OTHER

Audioblox U.K. Audioblox Program [Cited May 12, 2004]. <http://www.audiblox2000.com/uk/program.htm>.

Audioblox U.K. Dyslexia [Cited May 12, 2004]. <http://www.audiblox2000.com/uk/dyslexia.htm>.

Breznitz, Zvia. "The Speech and Vocalization Patterns of Boys with ADHD Compared with Boys with Dyslexia and Boys Without Learning Disabilities." Journal of Genetic Psychology. 164.4. December 2003. [Cited May 10, 2004]. <http://galenet.galegroup.com/servlet/HWRC>.>

"Dyslexia" The Dyslexia File, Center for Current Research. [Cited May 12, 2004]. <http://www.lifestages.com/health/dyslexia.html>.

Schoon, Chris. Piracetam FAQ Version 0.6. Dated 2/1/03. Last modified, March 14, 2004. [Cited May 10, 2004]. <http://www.erowid.org/smarts/piracetam/piracetamfaq.shtml>.

Katy Nelson, N.D.

Dyslexia

views updated Jun 11 2018

Dyslexia

Reading and the brain

How humans read

Causes of dyslexia

Treating dyslexia

Future developments

Resources

Dyslexia is a disorder that falls under the broad category of learning disabilities. It is often described as a neurological syndrome in which otherwise normal people have difficulty reading and writing. Dyslexia is not defined exactly the same by specialists in the United States. However, the key feature in all definitions, whether it comes from the U.S. federal government, the World Health Organization, or other organizations, seems to be the persons inability to read properly. The word dyslexia is derived from the Greek word dys (meaning poor or inadequate) and the word lexis (meaning words or language). Frequently, dyslexia is defined by what it is notdyslexia is not mental retardation, a psychiatric or emotional disorder, or a vision problem. Dyslexia is not caused by poverty, psychological problems, lack of educational opportunities, or laziness; those who are identified as dyslectic have normal or above-normal intelligence, normal eyesight, and tend to come from average families.

There are dozens of symptoms associated with dyslexia. In reading and writing, those with dyslexia may skip words, reverse the order of letters in a word (for instance, writing or reading was for saw), or drop some letters from a word (for example, reading run instead of running). They may concoct strange spellings for common words, have difficulty remembering and following sequences (like reciting the alphabet in order), and have cramped, illegible handwriting. There is often a gap between what the person seems to be capable of doing and performance;

it is not unusual for a student with dyslexia to earn straight As in science and fail English.

Reading and the brain

Austrian physiologist, medical doctor, psychologist Sigmund Freud (18561939) wrote in 1900 that painful childhood experiences or hatred of one or both parents caused dyslexia. He reasoned that children who could not openly rebel against a harsh mother or father defied their parents by refusing to learn to read. Freud recommended psychoanalysis to resolve such emotional problems.

Today, experts reject the psychoanalytic explanation of dyslexia. Sophisticated brain imaging technology known as functional magnetic resonance imaging (fMRI) clearly shows inactivity in a large area that links the angular gyrusthe visual cortex and visual association areas where print or writing is interpreted to areas in the superior temporal gyrus (Wernickes area) where language and phonetics are interpreted. In addition, during phonologic reading tasks, the area associated with spoken language (Brocas area) showed activation in dyslexic readers where it did not in normal readers. Researchers believe this area may attempt to compensate for impairments in Wernickes area.

Investigators have studied those with brain lesions (abnormal growths such as tumors) in Wernikes area. Although they had no reading difficulties before the lesion was large enough to detect, patients with brain lesions developed reading problems identical to those associated with dyslexia. Those with dyslexia also tend to have rapid, jerky, hard-to-control eye movements when they readanother indication of a misfire in the brain.

How humans read

Reading is a complicated chain of events coordinated in the brain. Imagine a busy, computerized railroad yard: trains pull in on hundreds of tracks from all directions. The cargo of each train is documented in a central tower and, then it is matched with a destination and assigned to one of dozens of tracks. Some trains may be sent to a holding area until their cargo is needed; others may be routed so they can make multiple stops. The computer system must analyze hundreds of pieces of information for each train pulling in, each train pulling outso even a brief power failure can clog the railroad yard with thousands of trains, blocked from reaching their destination.

Scientists suspect a similar power failure in the brain is the cause of dyslexia. In normal reading, the eye sends pictures of abstract images (the printed word) to the brain. Each symbol is routed to various portions of the brain for processing or storage, symbols are interpreted and combined in combinations that make sense, then transferred to other portions of the brain that recognize the importance of the messages. Sometimes the messages are relayed to the lips, tongue, and jawreading aloudor the fingers and handswriting.

Investigators have identified three major tracks (routes) for sending written messages to the brain for interpretation. The phonic route recognizes individual letters and, over time, builds a list of groups of letters that generally appear together. The direct route is a mental dictionary of whole words recognized as a unit; the lexical route breaks strings of letters into a base word, prefixes, and suffixes. The lexical route might, for example, break the word together into to-get-her. The areas of the brain are responsible for channeling words along these different routes, processing them, and then moving them along as a message that makes sense. They must coordinate thousands of pieces of information in normal reading. These bits of information are moved through the brain over neurons, the roadways of the nervous system, on neurotransmitters, naturally occurring chemicals that make it possible for messages to travel from one nerve cell to the next. In dyslexia, something jams the signals in the brain and interferes with the interpretation of the written word.

Causes of dyslexia

Researchers generally agree that genetics play a role in dyslexia. Studies of twins show that if one twin is dyslexic, the other is far more likely to have the disorder. Other studies show that dyslexia, that affects about 8% of the world population, tends to run in families. It is common for a child with dyslexia to have a parent or other close relative with the disorder. In the United States and England, about 10% of the population has dyslexic tendencies, where about 4% are severe and the other 6% are moderate in nature. In the United States, the major cause of illiteracy is dyslexia.

Because dyslexia affects males far more often than females (the rate is about three to one), investigators are exploring the relationship of male hormones to dyslexia. Several studies indicate that an excess of the male hormone testosterone prior to birth may slow the development of the left side of the fetuss brain. Other researchers argue, however, that those with dyslexia rarely have problems with spoken language, which is also controlled by the left side of the brain and depends on some of the same areas that control reading and writing.

Treating dyslexia

Those with mild cases of dyslexia sometimes learn to compensate on their own, and many with dyslexia reach remarkable levels of achievement. Leonardo Da Vinci (14521519), the famous Renaissance inventor and artist who painted the Mona Lisa, is thought to have been dyslexic; so was GermanAmerican physicist Albert Einstein (18791955).

The severity of the disorder, early diagnosis, and prompt treatment seem to be the keys to overcoming the challenges of dyslexia. Linguistic and reading specialists can help those with dyslexia learn how to break reading and writing into specific tasks, how to better remember and apply reading skills, and how to independently develop reading and writing skills. Studies with community college students indicate that intensive sessions with a specialist significantly increase a students reading and writing skills, and experts believe earlier intervention is even more effective.

Although dyslexia occurs independently, it can spark social, behavioral, and emotional problems. Children with dyslexia may be frustrated by their inability to understand and embarrassed by their failure in the classroom. They may perceive themselves as stupid and develop problems with self-esteem and motivation.

Future developments

There is no cure for dyslexia, however, skilled specialists are using phonics, self-esteem techniques, and sequencing to reduce the severity of the problem. Researchers are also exploring the use of various drugs

KEY TERMS

Angular gyrus A portion of the brain directly related to reading, located in the left side of the brain.

Frontal lobe A portion of the brain that controls planning, problem solving, and writing. Brocas area (the part of the brain that coordinates the movements of muscles used in speech) is located in the frontal lobe.

Occipital lobe The portion of the brain that accepts visual signals and combines and interprets them.

Wernickes area The portion of the left side of the brain that stores and retrieves words and word patterns.

known to affect chemical activity in the brain. Although MRI can not yet be used as a diagnostic tool, its use has proven the neurobiologic root to dyslexia and may help in devising methods of treatment.

Resources

BOOKS

Mortimore, Tilly. Dyslexia and Learning Style: A Practitioners Handbook. London, UK: Whurr, 2003.

Pollock, Joy. Day-to-day Dyslexia in the Classroom. London, UK, and New York: RoutledgeFalmer, 2004.

Shaywitz, Sally E. Overcoming Dyslexia: A New and Complete Science-based Program for Reading Problems at any Level. New York: Vintage Books, 2005.

Smythe, Ian, John Everatt, and Robin Salter, eds. International Book of Dyslexia: A Guide to Practice and Resources. Hoboken, NJ: Wiley, 2004.

OTHER

The International Dyslexia Association (IDA). Home page of IDA. <http://www.interdys.org/> (accessed October 9, 2006).

A. Mullig

Dyslexia

views updated May 14 2018

Dyslexia

What Is Dyslexia?

What Causes Dyslexia?

How Do People Know They Have Dyslexia?

How Is Dyslexia Diagnosed?

What Can Be Done about Dyslexia?

Living with Dyslexia

Can Dyslexia Be Cured?

Resources

Dyslexia (dis-LEX-ee-a) is a learning disability that affects a persons ability to interpret written words and write and spell properly.

KEYWORDS

for searching the Internet and other reference sources

Language disorders

Learning disabilities

Special education

Specific reading disability

What Is Dyslexia?

Dyslexia is a learning disability* that makes a person unable to recognize written words properly. It comes from the combination of two Greek words: dys, which means trouble, and lexia, which means words. Trouble with words in any language translates into difficulty with reading. Most people with dyslexia also have trouble with writing and spelling. In addition, some have difficulty with numbers. Dyslexia is sometimes referred to as specific reading disability.

* learning disability
refers to a disorder in the basic mental processes used for language or math. The disorder occurs in people of normal or above-normal intelligence. It is not the result of an emotional disturbance or of an impairment in sight or hearing.

Dyslexia affects about 10 to 15 percent of school-age children. About four out of every five children with dyslexia are boys. The disorder affects all races equally and is the most common type of learning disability.

What Causes Dyslexia?

No one knows for sure what causes dyslexia. However, scientists believe that it may be caused by a malfunction in part of the brain that recognizes and interprets words. Some scientists think that it is rooted in the development of the right side of the brain, which deals with processing words. When people with dyslexia look at or hear words, their eyes and ears work properly. However, a part of their brain misinterprets the words and delivers a faulty message back to them. In many cases, dyslexia may be genetic*, since people with the disorder often have a family history of learning disabilities.

* genetic
refers to a trait that is passed from parent to child through the genes, the hereditary material that helps determine many physical and mental characteristics.

One thing that is not related to having dyslexia is being unintelligent or lazy. People who have difficulty reading sometimes are told that they are stupid. This is not true. In fact, most people with dyslexia have normal or above-normal intelligence. They simply have a part of their brain that does not translate messages about written words correctly.

How Do People Know They Have Dyslexia?

Dyslexia usually is not diagnosed very early in a childs life, because children are not expected to learn to read until about age six. However, once children with dyslexia start school, they may have a very hard time keeping up with their classmates. Words and letters appear much differently

to a person with dyslexia than to a person without it. Sometimes words look all jammed together, while other times there seem to be spaces between words where they do not belong.

Reading Disability

When Tommy opened his history book, this is the story he saw:

Wenthe Pil grims la n bed ta Plymoutthey wer ein a mostbre carioussituation.T heye ar saw lateandther e wasmuc h sicknes s a mon g the sett I ers.

When Jason opened his book to the same page, this is what he saw:

When the Pilgrims landed at Plymouth they were in a most precarious situation. The year was late, and there was much sickness among the settlers.

For most people, reading about the first American settlers is easy and interesting. For some people, though, this passage is very difficult and frustrating to read, because it looks more like the first example, not the second. People who see or hear words this way have the disorder called dyslexia.

Some people with dyslexia see words backwards, as if they were viewing the words in a mirror. They may see ps where there should be bs; for example, pall instead of ball. They also may see words reversed; for example, was instead of saw. More often, people with dyslexia do not recognize that words are made up of small units of sound, known as phonemes*.

* phonemes
(FO-neemz) are the smallest units of spoken language, such as the puh sound at the start of the word pat.

Because reading goes hand in hand with writing, children with dyslexia often have a difficult time learning to write correctly. They may flip letters or write letters upside down. Letters that look similar may confuse such children when they try to write; for example, doll may become boll. Since the letters are shaped incorrectly, the childrens handwriting may be very hard to read. The ability to spell properly also is affected by dyslexia. Letters may not appear in the right order; for example, purple may become pruple. Some letters may be left out entirely, making the word puple.

When children have this kind of difficulty with reading, writing, and spelling, it is easy for them to fall behind in school and feel frustrated, even though they may be very intelligent. Not surprisingly, many adults with dyslexia say that they hated reading when they were young. Fortunately, most teachers today are trained to recognize dyslexia and take action to help the child.

How Is Dyslexia Diagnosed?

The first step in diagnosing dyslexia is often a thorough physical exam. The physician can run various tests, including vision and hearing tests, to rule out other problems. The physician also can do a neurologic exam* to measure how well the different parts of the nervous system are working.

* neurologic exam
refers to systematic tests of how well various parts of the nervous system are functioning.

If dyslexia is suspected, the physician may enlist the help of a specialist in learning disabilities. The specialist can administer tests to figure out how the childs brain processes information. The child may take an intelligence test* as well as academic achievement tests that assess reading and writing skills. Sometimes the child also may take tests that assess abilities in other areas, such as math, logic, and creative thinking.

* intelligence test,
also known as an IQ test refers to a test designed to estimate a persons intellectual potential.

Once testing is completed, the specialist can determine whether the child has dyslexia by comparing the childs intelligence test against the reading and writing tests. Average or high scores on an intelligence test and low scores on reading and writing tests are typical of people with dyslexia.

What Can Be Done about Dyslexia?

The earlier a child is diagnosed with dyslexia, and the earlier the childs family and teachers are made aware of the diagnosis, the better. Children with dyslexia must learn to read in a different way from those who do not have the disorder. Many children who do not have their dyslexia diagnosed until later do poorly in school year after year, as they try to learn to read the same way everyone else does. Eventually, after their dyslexia is diagnosed, they must go back and relearn how to read.

Whether it is a younger child with dyslexia who is first learning to read or an older child who is relearning, a special approach must be taken. In many cases, an individualized reading program is the first step. This means that a reading specialist creates a plan that is designed just for that child. The plan is based on many factors, such as how severe the childs dyslexia is and what the childs strengths are in other areas in school.

Dyslexia Hall of Fame

Many people with dyslexia go far beyond merely living up to their potential. Following is a list of just some of the famous people of today and times past who achieved their career dreams despite dyslexia or other learning disabilities:

Many times, the reading plan for a student with dyslexia will include a multisensory approach. This means that instead of just using the sense of sight, the student also will use other senses, such as touch or hearing. In some cases, a student might feel clay or wooden models of letters while saying the letters aloud. In other cases, the student might learn letter sounds while looking at pictures, or listen to letter sounds on a tape while looking at the letters. The student also can work with the reading specialist on phonemes. Eventually, the student learns to create combinations of phonemes to form words, and from there to recognize and read words.

Students with dyslexia can be taught in different settings. Some are placed in special classrooms with other students who have reading disabilities, while others work one-on-one with a reading specialist at certain points during the school day.

Various other types of therapy have been suggested for people with dyslexia, such as vision therapy (eye exercises) and colored glasses. However, none of these therapies have proved to be widely successful in treating the disorder.

Living with Dyslexia

Children with dyslexia face a special challenge: not only must they learn to read, but they also must learn to read in a special way. People with dyslexia usually learn to read very slowly, and it can take lots of practice. Emotional support is very important. Many children with dyslexia complain of feeling stupid because they cannot read as easily as most of their classmates. With enough help and support, however, children with dyslexia can learn to read and write well. The reading and writing level that a person with dyslexia can achieve depends a lot on the severity of the disorder. For example, someone with a mild form of dyslexia may learn to read and write very well, while another person with severe dyslexia may always find reading and writing more difficult.

Children with dyslexia usually grow up the same way that other children do: into healthy adults with normal lives. Many people with dyslexia go to college and excel in their classes, sometimes by using special methods such as tape recording their lectures or taking oral exams instead of written ones. Adults with dyslexia can do well in many different kinds of jobs.

Can Dyslexia Be Cured?

At present, there is no cure for dyslexia. There is no drug that people with dyslexia can take to correct the problem. Scientists constantly are studying the various parts of the brain to learn why information is interpreted incorrectly in some people. However, the brain is very complex, and there are still many mysteries about what causes dyslexia and other learning disabilities.

See also

Attention Deficit Hyperactivity Disorder

Resources

Books

Goldish, Meish. Everything You Need to Know About Dyslexia. New York: Rosen Publishing Group, 1998. An informational book for young people about dyslexia.

Moragne, Wendy. Dyslexia. Brookfield, CT: Millbrook Press, 1997. A book about dyslexia told through the true stories of teenagers with the disorder.

Organizations

LD Online. A website that offers information about learning disabilities for children, parents, and teachers.

http://www.ldonline.org

Learning Disabilities Association of America, 4156 Library Road, Pittsburgh, PA 15234-1349. A national organization for people with learning disabilities and their families.

http://www.ldanatl.org

National Information Center for Children and Youth with Disabilities, P.O. Box 1492, Washington, DC 20013-1492. A national information center that provides information to the public about learning disabilities and special education.

Telephone 800-695-0285
http://www.nichcy.org

The U.S. National Institutes of Health (NIH) and its member institutes have a Consumer Health Information website, with links to fact sheets about Learning Disabilities and about Why Children Succeed or Fail at Reading.

http://www.nih.gov/health/consumer/conkey.htm

Dyslexia

views updated May 29 2018

Dyslexia

Definition

Dyslexia is an unexpected impairment in reading and spelling despite a normal intellect.

Description

Dyslexia was first described by Hinshelwood in 1896. Orton originally hypothesized that dyslexia results from a dysfunction in visual memory and visual perception due to a delayment in maturation. Most dyslexics also display poor writing ability. Dyslexia is a classical primary reading disorder and should be differentiated from secondary disorders such as mental retardation , educational or environmental deprivation, or physical/organic diseases. The disorder results as a combination of genetic and environmental causes, which can induce variations in the behavioral, cognitive, and physiological measures related to reading disability. Dyslexia was previously called congenital word blindness. Dyslexia is a reading disorder, not caused by lowered motivation, inadequate learning opportunity or any overt neurological disability. Reading is a complex process which involves multiple systems to process the information cognitively and physiologically. In simple terms reading typically begins with a visual sensation stimuli and processing the text via the visual pathway in the brain (from the retina in the eye, the impulse goes in the brain to the lateral geniculate nuclei and primary visual cortex, the occipital lobe, located in the back of the head, which functions to process and integrate incoming visual information). Input information from vision is probably integrated with other neuronal systems that include language-specific rules, learned information and symbolic images into components of language thinking related to reading. Reading-related thinking is correlated with high activity in the left-hemisphere cortical regions, and language processing centers in the brain. Additionally, learning to read is also related to the learning process, which is mediated by the cerebellum and on relay feedback mechanisms between related areas of the brain.

Deficits in reading may stem from disruptions of simple sensory impairments to more complex problems involving thinking related to language. There are several subtypes of dyslexias and they can be categorized as either central or peripheral dyslexias (of which there are two, attentional dyslexia and neglect dyslexia), which result from impairment to brain processes that are capable of converting letters on the page into visual word forms. There are two types of peripheral dyslexias called attentional dyslexia, and neglect dyslexia. The attentional dyslexia subtype is a rare disorder of attention control, typically correlated with damage to the left parietal lobe (located on the sides of the head). The attentional dyslexia causes an impairment of reading words in sentences, since the defect causes many words to be visible at the same time. Neglect dyslexia is usually due to brain damage, and causes an impairment of reading because the affected person misidentifies letters in certain spatial regions of either a word or a group of words. The defect for neglect dyslexia subtype is associated with the right parietal lobe. Neglect dyslexia can be further divided into left neglect dyslexia and right neglect dyslexia. In the left neglect dyslexia subtype, the affected person experiences difficulty reading initial letters of the word, which may cause a letter(s) to be substituted, omitted or added. The right neglect dyslexia subtype causes a patient to have letter errors at the end of the word.

Letter-by-letter reading (LBL, pure alexia, or pure word blindness) is another form of peripheral dyslexia causing patients to have very slow reading performance with large effects on word length and response time. There is damage to the prestriate cortex of the occipital cortex and most patients also have a dense right visual field deficit. The damage impairs the word-form system in an abnormal way so that written words seem as random letter strings.

Central dyslexias are typically caused by disruption to neuronal processes correlated with sound analysis and meaning of written words. There are two major subtypes of central dyslexias which either impair semantic reading or nonsemantic reading. Semantic reading dyslexia is also referred to as deep and phonologic dyslexia. Semantic reading is due to extensive damage to the left hemisphere which results in a deficit whereby patients can only assemble the pronunciation of a word by first assessing its meaning. Affected individuals also make visual errors when reading. Nonsemantic reading, due to damage of the left temporal lobe causes patients to have difficulty reading exception words (i.e. shove), but can read correctly words that are common and similar (i.e. love).

Demographics

It is thought that dyslexia is the most common neurobehavioral disorder affecting children. The prevalence (existing cases) ranges from 5-10% of school-aged children (school and clinic identified) in the United States. However, these rates may be significantly more (up to 17.5%) in unselected populations. Research indicates that dyslexia is a chronic and persistent disorder. Evidence concerning gender predilection remains controversial. Dyslexia may also co-occur with another disorder called attention deficit/hyperactivity disorder (ADHD, 40% comorbidity). Dyslexia affects approximately 80% of children identified as manifesting a learning disorder.

Causes and symptoms

Persons affected with dyslexia have dysfunction developing an awareness of spoken and written words and segmenting smaller units of sound that are essential in an alphabetic language like English. Patients lose the ability to link and map printed symbols (letters) to sound.

Dyslexia runs in families. Studies demonstrate concordance rates of 68% for monozygotic twins and 37% for dizygote twins (Colorado Twin Study of Reading Disability). However, the genetic transmission is not simple and does not follow classical knowledge of trait heritability. Findings suggest that several genetic factors determine reading ability and the interactions of some or all factors determine the ultimate ability to read.

Evidence from neurobiological research utilizing high resolution imaging techniques, and brain measurement studies indicate differences in left temporo-parieto-occipital brain regions in dyslexic patients when compared to nonimpaired readers. Furthermore, evidence using functional brain imaging techniques in adult and children with dyslexia demonstrates a failure of normal left hemisphere posterior brain systems during reading with increased brain activation in frontal regions. This data indicates that impairment of posterior reading systems results in a disruption of the smoothly functioning and integrated reading system seen in nonimpaired persons. The impairment of posterior reading systems causes dyslexic persons to shift to ancillary neuronal systems to compensate for the deficit. It is the impairment in the posterior reading systems that prevents the development of skilled reading. Postmortem studies (confirmed in live subjects using MRI imaging) indicate a lack of symmetry in language-associated regions in the brain. The abnormal symmetry is associated with the common linguistic deficits that are characteristic of dyslexia.

The specific signs of dyslexia in both adults and school-aged children are similar. Patients exhibit inaccurate and labored decoding, word recognition, and text reading. They also exhibit difficulties in spelling and remain slow readers. Typical early symptoms can include difficulty playing rhyming games and problems with learning numbers and letters. Children often avoid reading independently and are unusually happy at the opportunity for parents to read to them.

Diagnosis

All cases and ages are diagnosed clinically by a combination of careful medical history, observation and psychological testing. There is no one test that is sufficient to render a definitive diagnosis. Rather, the diagnosis is made based on the results of all the clinical data attained. Dyslexia can be distinguished from other learning disorders by identifying the phonologic deficit. Family history and collateral data obtained from school and test results are essential. Tests to determine attention, memory, intelligence and math and language skills may be administered to establish the diagnosis.

Treatment team

The treatment team can consist of a neurologist , a pediatrician, and special education instructors. A clinical psychologist can perform psychological assessments (psychometric testing) to help establish the diagnosis. School and/or college counselors also comprise part of an effective and integrated treatment team.

Treatment

The management for dyslexic patients is lifelong. Early identification and intervention (remediation) of reading deficits involves specialist education. Intervention programs must systematically and explicitly teach phonics ensuring a clear understanding of how letters are linked to sounds (phonemes) and spelling. Typically individualized teaching is recommended to provide a balanced remedial program providing systematic instruction on phonemic awareness, phonics, vocabulary fluency and comprehension strategies. A well-integrated treatment program also includes opportunities for writing, reading, and discussing literature. A well-executed treatment program considers each component of the reading process to improve phonemic awareness and the ability to manipulate speech sounds.

Treatment for older persons (high school, college, and graduate school) is accommodation rather than remediation. College students require extra time with examination and reading/writing assignments. Other accommodations include recorded books, tape recorders in the classroom, tutorial services, alternatives to multiple choice questions and computer availability with spelling checkers.

Recovery and rehabilitation

Rehabilitation for dyslexics is a lifelong process. Early intervention in younger patients consists of a highly structured, integrated, systematic and explicit treatment program. A balanced treatment program should include the meaning and phonetic approaches to reading to ultimately improve language development (since dyslexia is a language-based disorder.) The program should allow for personalized instruction. Older persons require accommodation in college and at work versus remediation.

Clinical trials

There are two current clinical research trials entitled: Comprehensive Program to Improve Reading and Writing Skills in At-Risk and Dyslexic Children; and Using MRI to Evaluate Instructional Programs for Children with Developmental Dyslexia. Information can be obtained from http://www.ClinicalTrails.com.

Prognosis

Dyslexia is a lifelong disorder, but improvement is possible. Multiple learning disabilities can be expected, since the brain connections for reading, spelling, listening, speaking, and writing are part of the linguistic system. The prognosis can ultimately depend on associated comorbidities (other disorders associated with the primary disorder), early detection and intervention, and an intensive and comprehensive treatment plan.

Special concerns

Early recognition, intervention, and family members are important. Remediation programs must be delivered by highly-trained specialists, and treatment should be individualized.

Resources

BOOKS

Behrman, Richard, E., et al., eds. Nelson Textbook of Pediatrics. 17th ed. Philadelphia: Saunders, 2004.

PERIODICALS

Brow, W. E., A. L. Reiss, and S. Eliez. "Preliminary evidence of widespread morphological variations of the brain in dyslexia." Neurology 56, no. 6 (March 2001).

Bub, Danial. "Alexia and related reading disorders." Neurological clinics 21, no. 2 (May 2003).

Francks, C., and L. Macphie. "The genetic basis of dyslexia." The Lancet Neurology 1, no. 8 (December 2002).

Olitsky, Scott E. "Reading disorders in children." Pediatric Clinics of North America 50, no. 1 (February 2003).

Wood, F., and E. L. Grigorenko. "Emerging Issues in the Genetics of Dyslexia: A Methodological Preview." Journal of Learning Disabilities 34, no. 6 (November-December 2001).

WEBSITES

Dyslexia. <http://www.dyslexia.com>.

The International Dyslexia Association. <http://www.interdys.org>.

ORGANIZATIONS

The National Center for Learning Disabilities. 381 Park Avenue South, Suite 1401, New York, NY 10016. (212) 545-7510 or 888-575-7373; Fax: (212) 545-9665. <http://www.ncld.org>.

The International Dyslexia Association. 8600 LaSalle Road, Baltimore, MD 21286-2044. 410-296-0232 or 800-ABCD123; Fax: 410-321-5069. <http://www.interdys.org>.

Laith Farid Gulli, MD

Nicole Mallory, MS, PA-C

Robert Ramirez, DO

Dyslexia

views updated May 29 2018

Dyslexia

Definition

Dyslexia is a learning disability characterized by problems in reading, spelling, writing, speaking, or listening. It results from the inability to process graphic symbols. In many cases, dyslexia appears to be inherited.

Description

The word dyslexia is derived from the Greek word, dys (meaning poor or inadequate) and the word lexis (meaning words or language). Dyslexic children seem to have trouble learning early reading skills, problems hearing individual sounds in words, analyzing whole words in parts, and blending sounds into words. Letters such as "d" and "b" may be confused. Often a child with dyslexia has a problem translating language into thought (such as in listening or reading), or translating thought into language (such as in writing or speaking). Dyslexia is also referred to as developmental reading disorder (DRD).

Dyslexia is a problem involving higher (cortical) processing of symbols in the brain. Most children with dyslexia are of normal intelligence ; many have above-average intelligence. However, when a child is dyslexic, there is often an unexpected difference between achievement and aptitude. Each child with dyslexia has different strengths and weaknesses, although many have unusual talents in art, athletics, architecture, graphics, drama, music, or engineering. These special talents are often in areas that require the ability to integrate sight, spatial skills, and coordination.

Common characteristics of a child with dyslexia include problems with:

  • identifying single words
  • understanding sounds in words, sound order, or rhymes
  • spelling
  • transposing letters in words
  • handwriting
  • reading comprehension
  • the spoken language
  • understanding directions
  • understanding opposites, such as up/down or early/late

Social and emotional difficulties often accompany this disorder, as children are unable to meet expectations of parents and teachers and feel frustrated at their inability to achieve their goals. They may have a negative self-image and become angry, anxious, and depressed.

Demographics

About 1520 percent of the population of the United States has a language-based learning disability. Of students with specific learning disabilities receiving special education services, 7080 percent have deficits in reading. With such a high incidence, there is a question as to whether this is really a difference in learning style rather than a true "disability." The condition affects males more than females, and appears in all ages, races, and income levels.

Causes and symptoms

The underlying cause of dyslexia is not known, although research suggests the condition is often inherited. In 1999, The Centre for Reading Research in Norway presented the first research to study the largest family with reading problems ever known. By studying the reading and writing abilities of close to 80 family members across four generations, the researchers reported, for the first time, that chromosome 2 can be involved in the inheritability of dyslexia. When a fault occurs on this gene, it leads to difficulties in processing written language. Previous studies have pointed out linkages of other potential dyslexia genes to chromosome 1, chromosome 15 (DYX1 gene), and to chromosome 6 (DYX2 gene). The researchers who pinpointed the localized gene on chromosome 2 (DYX3) hope that this finding will lead to earlier and more precise diagnoses of dyslexia.

Research suggests a possible link with a subtle visual problem that affects the speed with which affected people can read. Anatomical and brain imagery studies show differences in the way the brain of a dyslexic child develops and functions.

Indicators of dyslexia include:

  • possible family history of learning disorders
  • difficulty learning to recognize written words
  • difficulty rhyming
  • difficulty determining the meaning (idea content) of a single sentence
  • writing or arithmetic learning problems

When to call the doctor

The doctor should be called if a child appears to have difficulty learning to read or exhibits any symptoms of dyslexia.

Diagnosis

Anyone who is suspected to have dyslexia should have a comprehensive evaluation, including medical, psychological, behavioral, hearing, vision, and intelligence testing. The test should include all areas of learning and learning processes, not only reading. Other causes of learning disabilities, such as attention deficit hyperactivity disorder (ADHD), affective disorders (e.g. depression or anxiety ), central auditory processing dysfunction, pervasive developmental disorders , and physical or sensory impairments, must be ruled out before the diagnosis of dyslexia can be confirmed. A child of any age may be evaluated for dyslexia using an age-appropriate battery of tests.

Test results are used to determine eligibility for special education services in many states as well as eligibility for programs in colleges and universities. They provide a basis for making educational recommendations, and determine the baseline for evaluation of improvement in the child's performance. In the United States, the Individuals with Disabilities Education Act (IDEA), Section 504 of the Rehabilitation Act of 1973 and the Americans with Disabilities Act (ADA) define the rights of children with dyslexia and other learning disabilities. These children are legally entitled to special services to help them overcome and accommodate their learning problems, including education programs to meet their needs. The Acts also protect people with dyslexia against unfair and illegal discrimination.

As further research pinpoints the genes responsible for some cases of dyslexia, there is a possibility that earlier testing will be established to allow for timely interventions to prevent the onset of the condition and treat it when it does occur. Unfortunately, in many schools, a child is not identified as having dyslexia until after repeated failures.

Treatment

Dyslexia is a life-long condition, but with proper intervention, a child can learn to read and/or write well. When a child is diagnosed with dyslexia, the parents should find out from the school or the diagnostician exactly what the problem is, what method of teaching is recommended, and why a particular method is suggested.

The primary focus of treatment is aimed at solving the specific learning problem of each affected child. Most often, this may include modifying teaching methods and the educational environment, since traditional educational methods will not always be effective with a dyslexic child. An Individual Education Plan (IEP) should be created for each child, reflecting his or her specific requirements. Special education services may include specialist help by an instructor specifically trained to teach dyslexic students through individualized tutoring or special day classes. It is important to teach these students using all the senseshearing, touching, writing, and speakingthrough a multi-sensory program.

People with dyslexia need a structured language program, with direct instruction in the letter-sound system. Teachers must provide the rules governing written language. Most experts agree that the teacher should emphasize the association between simple phonetic units with letters or letter groups, rather than an approach that stresses memorizing whole words.

To assist with associated social and emotional difficulties, teachers must use strategies that will help the child find success in academics and personal relationships. Such strategies include rewarding efforts and not just the results, helping the child set realistic goals, and encouraging the child to do volunteer work that requires empathy and a social conscience (for example, a child with dyslexia who does well in science or math could serve as a peer tutor in those subjects or could tutor a younger child with dyslexia). Psychological counseling may also be helpful.

Prognosis

There is a great deal of variation among different people with dyslexia, producing different symptoms and degrees of severity. The prognosis depends on the severity of the disability, but is usually good if the condition is diagnosed early, the intervention used is effective and appropriate for the specific child, and if the child has a strong self-image and supportive family, friends, and teachers. However, difficulties with reading may persist throughout adulthood, which may result in occupational problems in certain careers. However, many successful people, such as Erin Brockovich and Whoopi Goldberg, have dyslexia.

Prevention

Since learning disorders often run in families, affected families should try to recognize learning disability problems early. For families without a previous history of learning disabilities, an intervention can begin as early as preschool or kindergarten if teachers detect early signs.

Parental concerns

There are many resources available to aid parents in helping their children. For example, the International Dyslexia Association (<http://interdys.org>) provides extensive information for parents, teachers, and children. Parents are encouraged to utilize these resources to ensure their child's success in school and in interactions with their peers and later as working adults. They must also guard against feeling that the child is lazy or not trying hard. Instead, they should provide a supportive and loving environment.

Dyslexia may have an impact upon the child's family. Non-dyslexic siblings may be jealous of the attention, time, and money the dyslexic child receives from the parents. Since dyslexia runs in families, one or both parents may have had similar school problems. The child's problems may bring back feelings of frustration and failure for parents, which may interfere with their parenting skills.

KEY TERMS

Individualized educational plan (IEP) A detailed description of the educational goals, assessment methods, behavioral management plan, and educational performance of a student requiring special education services.

Learning disorders Academic difficulties experienced by children and adults of average to above-average intelligence that involve reading, writing, and/or mathematics, and which significantly interfere with academic achievement or daily living.

Spatial skills The ability to locate objects in a three-dimensional world using sight or touch.

See also Language delay; Language disorders.

Resources

BOOKS

Reid, Gavin.DyslexiaA Complete Guide for Parents. Hoboken, NJ: John Wiley & Sons, 2004.

Shaywitz, Sally. Overcoming Dyslexia: A New and Complete Science-Based Program for Overcoming Reading Problems at Any Level. New York: Knopf, 2003.

Stowe, Cynthia. How to Reach and Teach Children with Dyslexia: A Parent and Teacher Guide to Helping Students of All Ages Academically, Socially, and Emotionally. San Francisco, CA: Jossey-Bass, 2002.

ORGANIZATIONS

International Dyslexia Association. Suite 382, Chester Bldg., 8600 LaSalle Rd., Ste. 382, Baltimore, MD 21286-2044. (800) ABC-D123 or (410) 296-0232. <http://interdys.org/index.jsp/bibcit.composed>

Learning Disabilities Association. 4156 Library Rd., Pittsburgh, PA 15234-1349. (412) 341-1515; Fax: (412) 344-0224. <www.ldanatl.org>

Judith Sims Beth A. Kapes

Dyslexia

views updated May 14 2018

Dyslexia

Dyslexia is a disorder that falls under the broad category of learning disabilities. It is often described as a neurological syndrome in which otherwise normal people have difficulty reading and writing. Frequently, dyslexia is defined by what it is not—dyslexia is not mental retardation, a psychiatric or emotional disorder, or a vision problem. Dyslexia is not caused by poverty, psychological problems, lack of educational opportunities, or laziness; those who are identified as dyslectic have normal or above-normal intelligence, normal eyesight, and tend to come from average families.

There are dozens of symptoms associated with dyslexia. In reading and writing, those with dyslexia may skip words, reverse the order of letters in a word (for instance, writing or reading "was" for "saw"), or drop some letters from a word (for example, reading "run" instead of "running"). They may concoct strange spellings for common words, have difficulty remembering and following sequences (like reciting the alphabet in order), and have cramped, illegible handwriting. There is often a gap between what the person seems to be capable of doing and performance; it's not unusual for a student with dyslexia to earn straight As in science and fail English.


Reading and the brain

Sigmund Freud, the father of modern psychiatry , wrote in 1900 that painful childhood experiences or hatred of one or both parents caused dyslexia. He reasoned that children who could not openly rebel against a harsh mother or father defied their parents by refusing to learn to read. Freud recommended psychoanalysis to resolve such emotional problems.

Today, experts reject the psychoanalytic explanation of dyslexia. Sophisticated brain imaging technology known as functional magnetic resonance imaging (fMRI) clearly shows inactivity in a large area that links the angular gyrus—the visual cortex and visual association areas where print or writing is interpreted, to areas in the superior temporal gyrus (Wernicke's area) where language and phonetics are interpreted. Also, during phonologic reading tasks, the area associated with spoken language (Broca's area) showed activation in dyslexic readers where it did not in normal readers. Researchers believe this area may attempt to compensate for impairments in Wernicke's area.

Investigators have studied those with brain lesions (abnormal growths such as tumors) in Wernike's area. Although they had no reading difficulties before the lesion was large enough to detect, patients with brain lesions developed reading problems identical to those associated with dyslexia. Those with dyslexia also tend to have rapid, jerky, hard-to-control eye movements when they read—another indication of a misfire in the brain.

How we read

Reading is a complicated chain of events coordinated in the brain. Imagine a busy, computerized railroad yard: trains pull in on hundreds of tracks from all directions. The cargo of each train is documented in a central tower, then matched with a destination and assigned to one of dozens of tracks. Some trains may be sent to a holding area until their cargo is needed; others may be routed so they can make multiple stops. The computer system must analyze hundreds of pieces of information for each train pulling in, each train pulling out—so even a brief power failure can clog the railroad yard with thousands of trains, blocked from reaching their destination.

Scientists suspect a similar power failure in the brain is the cause of dyslexia. In normal reading, the eye sends pictures of abstract images (the printed word) to the brain. Each symbol is routed to various portions of the brain for processing or storage, symbols are interpreted and combined in combinations that make sense, then transferred to other portions of the brain that recognize the importance of the messages. Sometimes the messages are relayed to the lips, tongue, and jaw—reading aloud—or the fingers and hands—writing.

Investigators have identified three major "tracks" for sending written messages to the brain for interpretation. The phonic route recognizes individual letters and, over time , builds a list of groups of letters that generally appear together. The direct route is a "mental dictionary" of whole words recognized as a unit; the lexical route breaks strings of letters into a base word, prefixes, and suffixes. The lexical route might, for example, break the word "together" into "to-get-her." The areas of the brain responsible for channeling words along these different routes, processing them, then moving them along as a message that makes sense, coordinate thousands of pieces of information in normal reading. These bits of information are moved through the brain over neurons, the roadways of the nervous system , on neurotransmitters, naturally occurring chemicals that make it possible for messages to travel from one nerve cell to the next. In dyslexia, something jams the signals in the brain and interferes with the interpretation of the written word.


Causes of dyslexia

Researchers generally agree that genetics play a role in dyslexia. Studies of twins show that if one twin is dyslexic, the other is far more likely to have the disorder. Other studies show that dyslexia, which affects about 8% of the population, tends to run in families. It's common for a child with dyslexia to have a parent or other close relative with the disorder.

Because dyslexia affects males far more often than females (the rate is about three to one), investigators are exploring the relationship of male hormones to dyslexia. Several studies indicate that an excess of the male hormone testosterone prior to birth may slow the development of the left side of the fetus's brain. Other researchers argue, however, that those with dyslexia rarely have problems with spoken language, which is also controlled by the left side of the brain and depends on some of the same areas that control reading and writing.


Treating dyslexia

Those with mild cases of dyslexia sometimes learn to compensate on their own, and many with dyslexia reach remarkable levels of achievement. Leonardo Da Vinci, the famous Renaissance inventor and artist who painted the Mona Lisa, is thought to have been dyslexic; so was Albert Einstein.

The severity of the disorder, early diagnosis , and prompt treatment seem to be the keys to overcoming the challenges of dyslexia. Linguistic and reading specialists can help those with dyslexia learn how to break reading and writing into specific tasks, how to better remember and apply reading skills, and how to independently develop reading and writing skills. Studies with community college students indicate that intensive sessions with a specialist significantly increase a student's reading and writing skills, and experts believe earlier intervention is even more effective.

Although dyslexia occurs independently, it can spark social, behavioral, and emotional problems. Children with dyslexia may be frustrated by their inability to understand and embarrassed by their "failure" in the classroom. They may perceive themselves as "stupid" and develop problems with self-esteem and motivation.

Future developments

Researchers are exploring the use of various drugs known to affect chemical activity in the brain. Although fMRI can not yet be used as a diagnostic tool, its use has proven the neurobiologic root to dyslexia and may help in devising methods of treatment.


Resources

books

Selikowitz, Mark. Dyslexia and Other Learning Difficulties: The Facts. New York: Oxford University Press, 1993.

Ziminsky, Paul C. In a Rising Wind: A Personal Journey ThroughDyslexia. Lanham: University Press of America, 1993.

other

Facts About Dyslexia. National Institutes of Health, National Institutes of Child Health and Human Development. Washington, DC: U.S. Government Printing Office, 1993 (U.S. Government Printing Office NIH Publication 93-0384-P).


A. Mullig

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Angular gyrus

—A portion of the brain directly related to reading, located in the left side of the brain.

Frontal lobe

—A portion of the brain that controls planning, problem solving, and writing. Broca's area (the part of the brain that coordinates the movements of muscles used in speech) is located in the frontal lobe.

Occipital lobe

—The portion of the brain that accepts visual signals and combines and interprets them.

Wernicke's area

—The portion of the left side of the brain that stores and retrieves words and word patterns.

Dyslexia

views updated May 14 2018

Dyslexia

A reading disability that is not caused by an identifiable physical problem (such as brain damage, visual or auditory problems).

Dyslexia is a specific learning disability characterized by a significant disparity between an individual's general intelligence and his or her language skills, usually reflected in school performance.

Estimates of people with dyslexia range from 2% to the National Institutes of Health figure of 15% of the U.S. population. It is a complicated disorder with no identifiable cause or cure, yet it is highly responsive to treatment in the form of special instruction. The most obvious symptoms of the dyslexic show up in reading and writing, but listening, speaking, and general organizational skills are also affected. The dyslexic may have trouble transferring information across modalities, for example from verbal to written forms. The dyslexic's characteristic reversal of letters, confusion between similar letters such as "b" and "d," omission of words when reading aloud, trouble sounding out words, and difficulty following written instructions were first thought to be the result of vision and perceptual problemsi.e., a failure of taking in the stimulus. Only a small percentage of dyslexics have vision disorders, however, and it is now generally agreed by physicians, researchers, and educators that dyslexia is primarily a language disorder . Whereas the non-dyslexic intuitively learns phonic (sound) rules while learning to read, the dyslexic needs specific, methodical drill and practice to learn the visual-auditory associations necessary for reading comprehension and written expression.

Originally it was thought that dyslexia affected more males than females (in a ratio of 5:1), but later studies found males to be only slightly more likely than females to be dyslexic. Figures for diagnosed child dyslexics are skewed because for various reasons boys tend to be referred more frequently for special education . Diagnosis is complicated by the fact that anywhere from 20% to 55% of dyslexics also suffer from attention deficit/hyperactivity disorder (ADHD), a behavioral disorder which can aggravate reading problems. There are many different theories about the causes and classifications of different types of dyslexia, but few hard conclusions. It is definitely familial, and about 40% of boys and 20% of girls with a dyslexic parent show the disorder. Several genetic studies have found gene linkages which demonstrate heterogeneous (multiple methods of) transmission. Dyslexics have average or above average intelligence, and it is speculated that they have heightened visual-spatial and motor awareness. Thomas Edison, Albert Einstein, Woodrow Wilson, General George Patton, and Auguste Rodin are thought to have been dyslexic.

There are many treatment approaches available to the public, ranging from visual stimulation to diets to enhancement of regular language education. However, it is generally agreed that specialized education is the only

successful remedy, and the American Academy of Ophthalmology, the American Academy of Pediatrics, and the American Association for Pediatric Ophthalmology and Strabismus have issued a policy statement warning against visual treatments and recommending a cross-disciplinary educational approach. In fact the first researcher to identify and study dyslexia, Samuel Torrey Orton, developed the core principles of such an approach in the 1920s. The work of three of his followersteachers Bessie Stillman, Anna Gillingham, and Beth Slingerlandunderlies many of the programs in wide use today such as project READ, the Wilson Reading System, and programs based on the Herman method. These and other successful programs have three characteristics in common. They are:

(1) Sound/symbol based. They break words down into their smallest visual components: letters and the sounds associated with them.

(2) Multisensory. They attempt to form and strengthen mental associations among visual, auditory, and kinesthetic channels of stimulation. The dyslexic simultaneously sees, feels, and says the sound-symbol association; for example, a student may trace the letter or letter combination with his finger while pronouncing a word out loud.

(3) Highly structured. Remediation begins at the level of the single letter-sound, works up to digraphs, then syllables, then into words and sentences in a very systematic fashion. Repetitive drill and practice serve to form necessary sound-symbol associations.

If caught early, especially before the third grade, dyslexia is highly treatable through special education.

Further Reading

Bowler, Rosemary F., ed. Annals of Dyslexia. Baltimore, MD: The Orton Dyslexia Society, 1983.

Galaburda, A., ed. Dyslexia and Development: Neurobiological Aspects of Extraordinary Brains. Cambridge, MA: Harvard UP, 1993.

Miles. T.R. Dyslexia. Philadelphia: Open University Press, 1990.

Lytle, Vicky. "Edison, Rockefeller, Rodin, and the Reading Problem: Detecting Dyslexia in Students." NEA Today 4, (October 1985): 10-11.

Rooney, Karen. "Dyslexia Revisited: History, Educational Philosophy, and Clinical Assessment Applications." Intervention in School and Clinic 31, no. 1, (1995): 6-15.

Rumsey, Judith M. "The Biology of Developmental Dyslexia: Grand Rounds at the Clinical Center of the National Institutes of Health." JAMA 19, no. 7, (1992): 912-16.

Further Information

Council for Learning Disabilities. P.O. Box 40303, Overland Park, KS 66204.

Foundation for Children with Learning Disabilities. 99 Park Avenue, New York, NY 10016.

Orton Dyslexia Society. 8600 LaSalle Road, Chester Building, Suite 382, Baltimore, MD 21286-2044, (410) 2960232, information line: (800) ABC-D123.

Dyslexia

views updated May 18 2018

Dyslexia

Definition

Dyslexia is a learning disability characterized by problems in reading, spelling, writing, speaking, or listening. In many cases, dyslexia appears to be inherited.

Description

The word dyslexia is derived from the Greek word, dys (meaning poor or inadequate) and the word lexis (meaning words or language).

The National Institutes of Health estimates that about 15% of the United States population is affected by learning disabilities, mostly with problems in language and reading. The condition appears in all ages, races, and income levels. Dyslexia is not a disease, but describes rather a different kind of mind that learns in a different way from other people. Many people with the condition are gifted and very productive; dyslexia is not at all linked to low intelligence. In fact, intelligence has nothing to do with dyslexia.

Dyslexic children seem to have trouble learning early reading skills, problems hearing individual sounds in words, analyzing whole words in parts, and blending sounds into words. Letters such as "d" and "b" may be confused.

When a person is dyslexic, there is often an unexpected difference between achievement and aptitude. However, each person with dyslexia has different strengths and weaknesses, although many have unusual talents in art, athletics, architecture, graphics, drama, music, or engineering. These special talents are often in areas that require the ability to integrate sight, spatial skills, and coordination.

Often, a person with dyslexia has a problem translating language into thought (such as in listening or reading), or translating thought into language (such as in writing or speaking).

Common characteristics include problems with:

  • identifying single words
  • understanding sounds in words, sound order, or rhymes
  • spelling
  • transposing letters in words
  • handwriting
  • reading comprehension
  • delayed spoken language
  • confusion with directions, or right/left handedness
  • confusion with opposites (up/down, early/late, and so on)
  • mathematics

Causes and symptoms

The underlying cause of dyslexia is not known, although research suggests the condition is often inherited. In 1999, The Centre for Reading Research in Norway presented the first research to study the largest family with reading problems ever known. By studying the reading and writing abilities of close to 80 family members across four generations the researchers reported, for the first time, that chromosome 2 can be involved in the inheritability of dyslexia. When a fault occurs on this gene it leads to difficulties in processing written language. Previous studies have pointed out linkages of other potential dyslexia genes to chromosome 1, chromosome 15 (DYX1 gene), and to chromosome 6 (DYX2 gene). The researchers who pinpointed the newly localized gene on chromosome 2 (DYX3) hope that this finding will lead to earlier and more precise diagnoses of dyslexia.

New research suggests a possible link with a subtle visual problem that affects the speed with which affected people can read. Other experts believe that dyslexia is related to differences in the structure and function of the brain that manifests differently in different people.

Diagnosis

Anyone who is suspected to have dyslexia should have a comprehensive evaluation, including hearing, vision, and intelligence testing. The test should include all areas of learning and learning processes, not just reading.

As further research pinpoints the genes responsible for some cases of dyslexia, there is a possibility that earlier testing will be established to allow for timely interventions to prevent the onset of the condition and to treat it when it does occur. Unfortunately, in many schools, a child is not identified as having dyslexia until after repeated failures.

Treatment

If a child is diagnosed with dyslexia, the parents should find out from the school or the diagnostician exactly what the problem is, and what method of teaching is recommended and why. No single method will work with every child, and experts often disagree as to the best method to use.

The primary focus of treatment is aimed at helping the specific learning problem of each affected person. Most often, this may include modifying teaching methods and the educational environment, since traditional educational methods will not always work with a dyslexic child.

People with dyslexia need a structured language program, with direct instruction in the letter-sound system. Teachers must give the rules governing written language. Most experts agree that the teacher should emphasize the association between simple phonetic units with letters or letter groups, rather than an approach that stresses memorizing whole words.

It is important to teach these students using all the senses: hearing, touching, writing, and speaking, provided by an instructor who is specifically trained in a program that is effective for dyslexic students.

Prognosis

Many successful and even famous people have dyslexia. How well a person with dyslexia functions in life depends on the way the disability affects that person. There is a great deal of variation among different people with dyslexia, producing different symptoms and different degrees of severity.

Prognosis is usually good if the condition is diagnosed early, and if the person has a strong self image with supportive family, friends, and teachers. It is imperative for a good outcome that the person be involved in a good remedial program.

KEY TERMS

Spatial skills The ability to locate objects in three dimensional world using sight or touch.

Resources

PERIODICALS

Fagerheim, Toril, et al. "A New Gene (DYX3) for Dyslexia is Located on Chromosome 2." Journal of Medical Genetics 36 (September 1999): 664-669.

Dyslexia

views updated May 29 2018

DYSLEXIA

DEFINITION


Dyslexia is a learning disability (see learning disorders entry) characterized by problems with reading, spelling, writing, speaking, or listening. In many cases, dyslexia appears to be hereditary.

DESCRIPTION


Dyslexia is not a disease. It is a condition in which a person's brain learns in a different way from that of other people. Many people with dyslexia are very intelligent and successful. The condition has nothing to do with a person's intelligence. Dyslexics are often highly talented in many areas, including art, athletics, drama, music, and engineering. These talents often require the ability to bring together sight, spatial skills (the ability to locate objects in three-dimensional space using sight and/or touch), and coordination.

The U.S. National Institutes of Health estimate that about 15 percent of the U.S. population has some form of learning disorder. Those learning disorders are usually related to the use of language and reading. Learning disorders occur in people of all ages, races, and income levels.

CAUSES


The basic cause of dyslexia is not known. Some experts believe that the condition may be hereditary. Others suggest that it may be caused by differences in the structure of a person's brain and the way that brain functions.

SYMPTOMS


The symptoms of dyslexia are well known. Children with the disorder have trouble learning to read. They may also have problems with hearing the individual sounds in words and understanding how those sounds go together to make a word. They have a tendency to confuse certain letters, such as "b" and "d."

Often a person with dyslexia has a problem translating language into thought, as one does when listening and reading; or translating thought into language, as in writing and speaking.

Common symptoms of dyslexia include problems with:

  • Identifying single words
  • Understanding sounds in words, sound order, or rhymes
  • Spelling
  • Transposing (reversing) letters in words
  • Handwriting
  • Reading comprehension (understanding)
  • Delayed spoken language
  • Confusion with directions or handedness (right-versus left-handedness)
  • Confusion with certain concepts, such as "up" and "down," "early" and "late," and so on
  • Mathematics

DIAGNOSIS


A child suspected of being dyslexic should have a complete evaluation. The child's vision, hearing, and intelligence should be tested. The tests should cover all areas of learning, not just reading.

Testing is important because many dyslexic children are not identified early. Teachers and parents may attribute problems in school to factors other than dyslexia and delay treatments that can help the child.

TREATMENT


No single treatment works best with every child. Experts often disagree as to the best method to use. Treatment methods should be designed for each specific child, depending on his or her own individual problems.

People with dyslexia often need a structured language program. Teachers need to focus on the sound of letters and the way they are put together in words. There needs to be a focus on the rules that govern written language. Emphasis should be placed on the individual phonetic (sound) units of words in speech, reading, and writing, rather than on memorizing complete words.

It is important to teach dyslexic students using all of the following functions: hearing, touching, writing, and speaking. This instruction can best be provided by teachers who have specialized training in programs for dyslexic students.

PROGNOSIS


The prognosis for dyslexics is very good. Many successful people have dyslexia. The ability to perform well in daily life depends to a large extent on the specific problems an individual has.

The prognosis is better when dyslexia is diagnosed early. Helping a person to develop a strong self-image and providing support from family, friends, and teachers are important factors. A good remedial program is essential in order to make the greatest progress possible.

PREVENTION


There is no known method for preventing dyslexia.

FOR MORE INFORMATION


Books

Davis, Ronald D., and Sheldon M. Braun. The Gift of Dyslexia: Why Some of the Smartest People Can't Read and How They Can Learn. New York: Perigee, 1997.

Guyer, Barbara P., and Sally E. Shaywitz. The Pretenders: Gifted People Who Have Difficulty Learning. Homewood, IL: High Tide Press, 1997.

Irlen, Helen. Reading by the Colors: Overcoming Dyslexia and Other Reading Disabilities through the Irlen Method. Garden City Park, NY: Avery Publishing Group, 1991.

Nosek, Kathleen. Dyslexia in Adults: Taking Charge of Your Life. Dallas: Taylor Publishing, 1997.

Nosek, Kathleen. The Dyslexic Scholar: Helping Your Child Succeed in the School System. Dallas: Taylor Publishing, 1995.

Organizations

International Dyslexia Association (formerly the Orton Dyslexia Society). 8600 LaSalle Rd., Chester Building, Suite 382, Baltimore, MD 21286. (800) ABCD123.

Learning Disabilities Association. 4156 Library Rd., Pittsburgh, PA 15234. (412) 3411515.

Dyslexia

views updated May 23 2018

Dyslexia

Dyslexia is a learning disorder characterized by difficulty reading and writing. Dyslexia is not caused by poverty, psychological problems, lack of education, or laziness. People who are identified as dyslexic generally have normal or above-normal intelligence, normal eyesight, and tend to come from average families. It is not unusual for a student with dyslexia to fail English while earning straight As in science.

There are dozens of symptoms associated with the disorder. Dyslexic people may skip words, reverse the order of letters in a word (writing or reading "was" for "saw"), or drop some letters from a word (reading "run" instead of "running"). They may invent strange spellings for common words, have difficulty remembering and following sequences (like reciting the alphabet in order), and have cramped, illegible handwriting.

Causes of dyslexia

Scientists generally agree that dyslexia results from a neurological problem in the areas of the brain involved in reading. Several regions of the brainall located in the brain's left sidehave been identified as controlling the complicated task of reading and writing. What part of the reading task is processed in each area is not yet clear. Even more mysterious is how the brain translates abstract symbols like printed letters into ideas.

In normal reading, the eye sends pictures of abstract symbols to the brain. Each symbol is then transferred along different routes to various portions of the brain for interpretation. Scientists suspect that in a dyslexic person, something jams the transfer of that information.

Scientists generally agree that genetics plays a role in dyslexia. Studies of twins show that if one twin is dyslexic, the other is likely to have the disorder. Other studies show that the disorder, which affects about 8 percent of the population, tends to run in families. It is common for a child with dyslexia to have a parent or other close relative with the disorder. Because 90 percent of dyslexic people are male, scientists are investigating the relationship of male hormones to the disorder.

Treating dyslexia

Those with mild cases of dyslexia sometimes learn to compensate on their own. Many reach remarkable levels of achievement. Italian artist, scientist, and engineer Leonardo da Vinci (14521519) is thought to have been dyslexic. It is also believed that German-born American physicist Albert Einstein (18791955) was dyslexic.

Early diagnosis and prompt treatment seem to be the keys to over-coming the challenges of dyslexia. Linguistic (language) and reading specialists can help those with the disorder learn how to develop and apply reading and writing skills.

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