Dyslexia is a specific reading disability due to a defect in the brain's processing of graphic symbols.
It is a learning disability that alters the way the brain processes written material and is typically characterized by difficulties in word recognition, spelling, and decoding.
People with dyslexia have problems with reading comprehension.
The National Center for Learning Disabilities says that dyslexia is a neurological and often genetic condition, and not the result of poor teaching, instruction, or upbringing.
Dyslexia is not linked to intelligence.
Fast facts on dyslexia
Here are some key points about dyslexia. More detail and supporting information is in the main article.
- Dyslexia is not related to intelligence
- People with dyslexia are more likely to develop immunological problems
- The content of dyslexia tests vary dependent on the age of the individual
What is dyslexia?
Dyslexia commonly causes difficulties in word recognition, spelling, and decoding.
The problem in dyslexia is a linguistic one, not a visual one. Dyslexia in no way stems from any lack of intelligence. People with severe dyslexia can be brilliant.
The effects of dyslexia, in fact, vary from person to person. The only shared trait among people with dyslexia is that they read at levels significantly lower than typical for people of their age.
Dyslexia is different from delayed reading development, which may reflect mental disability or cultural deprivation.
According to the University of Michigan Health System, dyslexia is the most common learning disability. Eighty percent of students with learning disabilities have dyslexia.
The International Dyslexia Association estimates that 15-20 percent of the American population have some of the symptoms of dyslexia, including slow or inaccurate reading, poor spelling, poor writing, or mixing up similar words.
Dyslexia affects people of all ethnic backgrounds, although a person's native language can play an important role. A language where there is a clear connection between how a word is written and how it sounds, and consistent grammatical rules, such as in Italian and Spanish, can be easier for a person with mild to moderate dyslexia.
However, languages such as English, where there is often no clear connection between the written form and sound, as in words such as "cough" and "dough," can be more challenging for a person with dyslexia.
Symptoms of dyslexia
The most common signs and symptoms associated with dyslexia are:
- Learning to read - the child, despite having normal intelligence and receiving proper teaching and parental support, has difficulty learning to read.
- Milestones reached later - the child learns to crawl, walk, talk, and ride a bicycle later than the majority of other kids.
- Speech - apart from being slow to learn to speak, the child commonly mispronounces words, finds rhyming extremely challenging, and does not appear to distinguish between different word sounds.
- Slow at learning sets of data - at school, the child takes much longer than the other children to learn the letters of the alphabet and how they are pronounced. There may also be problems remembering the days of the week, months of the year, colors, and some arithmetic tables.
- Coordination - the child may seem clumsier than their peers. Catching a ball may be difficult.
- Left and right - the child commonly gets "left" and "right" mixed up.
- Reversal - numbers and letters may be reversed without realizing.
- Spelling - might not follow a pattern of progression seen in other children. The child may learn how to spell a word today and completely forget the next day.
- Phonology problems - phonology refers to the speech sounds in a language. If a word has more than two syllables, phonology processing becomes much more difficult. For example, with the word "unfortunately" a person with dyslexia may be able to process the sounds "un" and "ly," but not the ones in between.
- Concentration span - children with dyslexia commonly find it hard to concentrate. Many adults with dyslexia say this is because, after a few minutes of non-stop struggling, the child is mentally exhausted. A higher number of children with dyslexia also have ADHD (attention deficit hyperactivity disorder), compared with the rest of the population.
- Sequencing ideas - when a person with dyslexia expresses a sequence of ideas, they may seem illogical.
- Autoimmune conditions - people with dyslexia are more likely to develop immunological problems, such as hay fever, asthma, eczema, and other allergies.
Causes of dyslexia
A child with dyslexia may have more difficulty than usual in reading, spelling, and concentrating.
Specialist doctors and researchers are not sure what causes a person to develop dyslexia.
Some evidence points to the possibility that the condition is inherited, as dyslexia often runs in families.
Genetic causes of dyslexia
A team at the Yale School of Medicine found that defects in a gene, known as DCDC2, were associated with problems in reading performance.
A small minority of people with dyslexia acquired the condition after they were born. The most common causes of acquired dyslexia are brain injuries, stroke, or some other type of trauma.
Humans have the ability to understand spoken language; it is something the brain acquires easily and naturally from a very early age. That is why during very early childhood (3 years) we can utter and understand relatively complicated sentences.
This natural ability to acquire language explains why, when we listen to verbal communication, we do not consciously register that words are made up of individual sounds, we only hear the word itself. The smallest units of sound that make up a word are called phonemes.
For example, when we hear the word "Kangaroo," we hear it as a whole, seamless utterance. We do not need to break it down into the phonemes - "kan" "ga" "roo," then put them together again in order to make sense of it.
This is the case only when we learn to speak and hear speech, not when we are learning to read and write. When we learn how to read or write, we need to be able to initially recognize the letters that make up a word and then use them to identify the phonemes, and put them together to make sense of the word - this is called phonological processing.
Experts say that people with dyslexia have problems with phonological processing.
If a parent, guardian, or teacher suspects a child may have dyslexia, a professional evaluation to better understand the problem will pave the way to more effective treatment.
The test results may also open the door to more support for the child, he or she may become eligible for special education services, support programs, and services later on in colleges and universities.
The type of test and how it is carried out will vary depending on the age of the person and what problems they have.
Diagnostic tests often cover the following areas:
- Background information
- Oral language skills
- Word recognition
- Decoding - the ability to read new words by using letter-sound knowledge
- Phonological processing
- Automaticity/fluency skills
- Reading comprehension
- Vocabulary knowledge
- Family history and early development
During the assessment process, the examiner needs to be able to rule out other conditions or problems that may show similar symptoms. Examples include vision problems, hearing impairment, lack of instruction, and social and economic factors.
Treatments for dyslexia
It is important for family members and the person with dyslexia to remember that dyslexia is not a disease. We live in a society where reading and writing are integral parts of everyday life - interventions that help people with dyslexia are aimed at improving their coping skills.
There is currently no "cure" for dyslexia. There are, however, a range of specialist and well-targeted interventions that can help children and adults improve their reading and writing skills.
The sooner a child is diagnosed and receives support, the more likely he or she will achieve long-term improvements.
Psychological testing helps the teacher develop a better-targeted teaching program for the child.
A teacher who is trained in helping children with dyslexia will use a range of techniques to improve the child's reading skills. These techniques usually involve tapping into the child's senses, including touch, vision, and hearing.
Some children find that tracing their finger around the shape of letters helps them process data more effectively.
It is vital for the child's self-esteem and personal ambition that he or she is reminded that even though reading and writing may be a problem, millions of people with dyslexia worldwide have thrived and become successful and productive citizens.
According to the Brain Foundation, Australia: "Although the outlook for people with dyslexia depends on the severity of their disorder, the majority live normal, productive lives."