Learning disorders involve an inability to acquire, retain, or broadly use specific skills or information, resulting from deficiencies in attention, memory, or reasoning and affecting academic performance.
Learning disorders are quite different from intellectual disability (previously called mental retardation—see Intellectual Disability) and occur in children with normal or even high intellectual function. Learning disorders affect only certain functions, whereas in children with intellectual disability, difficulties affect cognitive functions broadly. Three common types of learning disorders are
Thus, children with learning disorders may have significant difficulty understanding and learning math, but have no difficulty reading, writing, and doing well in other subjects. Dyslexia is the best known of the learning disorders. Learning disorders do not include learning problems that are due primarily to problems of vision, hearing, coordination, or emotional disturbance.
Although the causes of learning disorders are not fully understood, they include abnormalities in the basic processes involved in understanding or in using spoken or written language or numerical and spatial reasoning.
Although the number of children with learning disorders is unknown, about 5% of the school-age population in the United States receives special educational services for learning disorders. Boys with learning disorders may outnumber girls five to one, although girls are often not recognized or diagnosed as having learning disorders.
Many children with behavioral problems do poorly in school and are tested by educational psychologists for learning disorders. However, some children with certain types of learning disorders hide their deficits well, avoiding diagnosis, and therefore treatment, for a long time.
Young children may be slow to learn the names of colors or letters, to assign words to familiar objects, to count, and to progress in other early learning skills. Learning to read and write may be delayed. Other symptoms may be a short attention span and distractibility (mimicking attention-deficit/hyperactivity disorder—see Attention-Deficit/Hyperactivity Disorder), halting speech, and a short memory span. Affected children may have difficulty with activities that require fine motor coordination, such as printing and copying.
Children with learning disorders may have difficulty communicating. Some children initially become frustrated and later develop behavioral problems, such as being easily distracted, hyperactive, withdrawn, shy, or aggressive.
Children who are not reading or learning at the grade level expected for their verbal or intellectual abilities should be evaluated. Testing of hearing and eyesight should be done, because problems with these senses can also interfere with reading and writing skills. Hearing and vision disorders should not be mistaken for a learning disorder.
Doctors examine children for any physical disorders. Children take a series of intelligence tests, both verbal and nonverbal, and academic tests of reading, writing, and arithmetic skills. Often these tests can be done by specialists at the child's school, at the parents' request.
The most useful treatment for a learning disorder is education that is carefully tailored to the individual child. Measures such as eliminating food additives, taking large doses of vitamins, and analyzing the child's system for trace minerals are often tried but unproven. No drug treatment has much effect on academic achievement, intelligence, and general learning ability. Because some children with a learning disorder also have attention-deficit/hyperactivity disorder, certain drugs, such as methylphenidate, may improve attention and concentration, enhancing their ability to learn.
Dyslexia is a specific reading disorder involving difficulty separating single words from groups of words and parts of words (phonemes) within each word.
Dyslexia is a particular type of learning disorder. No estimates of the number of children affected by dyslexia exist, but about 15% of school children receive adaptations or special instruction for reading difficulties. It is identified in more boys than girls. However, it may simply go unrecognized more often in girls. Dyslexia tends to run in families.
Dyslexia occurs when the brain has difficulty making the connection between sounds and symbols (letters). This difficulty is caused by poorly understood problems with certain connections in the brain. The problems are present from birth and may cause spelling and writing errors and reduced speed and accuracy when reading aloud. Although the letter reversals that often occur in children with dyslexia suggest visual problems, in most cases the problems are related to how sounds are perceived. People with dyslexia do not have problems understanding spoken language.
Symptoms and Diagnosis
Preschool children with dyslexia may be late in speaking, have speech articulation problems, and have difficulty remembering the names of letters, numbers, and colors. Children with dyslexia often have difficulty blending sounds, rhyming words, identifying the positions of sounds in words, segmenting words into sounds, and identifying the number of sounds in words. Delays or hesitations in choosing words, making word substitutions, and naming letters and pictures are early indicators of dyslexia. Problems with short-term memory for sounds and for putting sounds in the correct order are common.
Many children with dyslexia confuse letters and words with similar ones. Reversing the letters while writing—for instance, on instead of no, and saw instead of was—or confusing letters—for instance, b instead of d, w instead of m, n instead of h—is common. However, many children without dyslexia reverse letters during early elementary school years.
Children who are not progressing in word learning skills by the middle or end of first grade should be tested for dyslexia. Testing is usually conducted by school personnel and includes speech, language, and hearing tests, intelligence tests, and tests of academic skills.
The best treatment for word recognition is direct instruction that incorporates multisensory approaches. This type of treatment consists of teaching phonics with a variety of cues, usually separately and, when possible, as part of a reading program.
Indirect instruction for word recognition is also helpful. This instruction usually consists of training to improve word pronunciation or reading comprehension. Children are taught how to process sounds by blending sounds to form words, by separating words into segments, and by identifying the positions of sounds in words.
Component-skills instruction for word recognition is also helpful. It consists of training to blend sounds to form words, to segment words into word parts, and to identify the positions of sounds in words.
As children with dyslexia get older, compensatory strategies may be helpful. These strategies can include use of audio books, computer screen readers (available on most computers), digital recorders, and other technologic adaptations.
Indirect treatments, other than those for word recognition, may be used but are not recommended. Indirect treatments can include using tinted lenses that allow words and letters to be read more easily, eye movement exercises, or visual perceptual training. Drugs such as piracetam have also been tried. The benefits of most indirect treatments have not been proved and may provide unrealistic expectations and delay the teaching that is needed.
Last full review/revision November 2013 by Stephen Brian Sulkes, MD