Learning Disabilities: Overview

Learning disabilities are disorders that affect people's ability to receive or process information. A person with a learning disability may have specific difficulties with language, visual information, or coordination, which in turn can impair their ability to use written or spoken language, or to acquire basic mathematical skills.

Learning disabilities differ from learning problems (which are less severe) and from intellectual disabilities. Not every learning problem is a true disorder or disability. Some children are just naturally slower than others in developing certain skills, but most children usually catch up and achieve within the normal range for their age and abilities. Children who are intellectually disabled, by contrast, are not able to learn and function socially like other children in their age group. Their general intellectual capacity is lower than average. Children with intellectual disability have learning problems but do not have learning disabilities in the strict sense.

Children with learning disabilities typically have average or even above-average intelligence, which means that there is a marked difference between their intellectual ability and what they actually learn. In a sense, a person with a learning disability is like a radio that is not tuned exactly to a station. There is nothing wrong with the radio itself or with the signal coming from the station, but the sound is still fuzzy. Similarly, people with learning disabilities can see and hear as well as others, and they have a normal general learning capacity, but there is a problem with the way their brains process information.

Learning disabilities are generally classified into two main categories: verbal (having to do with the uses of spoken and written words) and nonverbal (having to do with interpreting visual or spatial information).

One in five students, or 15 to 20 percent of the general population in Canada and the United States, has a language-based learning disability. Developmental speech disorders are usually diagnosed in very young children who have persistent trouble making certain speech sounds; for example, they may say “wabbit” instead of “rabbit” or “thwim” instead of “swim.” These speech disabilities often improve with age or with the help of a speech therapist.

Developmental language disorders involve the way that children express themselves or how they understand others’ speech. Children with this type of disorder may speak in short phrases instead of full sentences; call objects by the wrong names; have disorganized speech; misunderstand words; or have difficulties following directions.

Reading is a complex task in which a person has to focus attention on the printed symbols, control eye movements across the page, recognize sounds associated with letters, understand words and grammar, build images and ideas, compare new ideas to what is already known, and then store the ideas in memory. This process requires a rich and intact network of nerve cells that connect the brain's centers of vision, language, and memory. A problem in any of these areas or the connections among them can lead to difficulties with reading. Dyslexia (dis-LEKS-ee-uh), the most common and best known of the reading disorders, affects between 2 and 15 percent of school-age children. Because children with dyslexia have trouble processing the smallest units of language that make up words, they may have trouble with rhyming games or with sounding out individual letters or syllables to form words.

There are other types of reading disorders that affect comprehension (KOM-pre-HEN-shun), the ability to fully understand and interpret what one reads. A person with this type of disability can read each word but may find it hard to understand the text, form images, or relate new ideas in the text to those already stored in memory. These reading disabilities are usually discovered at a later age than dyslexia.

A writing disability can result from problems with any area of the brain that controls grammar, hand movement, vocabulary, and memory. Children who have trouble mastering the motor skills needed for writing are said to have dysgraphia (dis-GRAF-ee-uh).

Nonverbal learning disorder (also called nonverbal learning disabilities, or NVLD) is not as well understood as verbal learning disabilities. People with NVLD often have problems with visual perception, recall of visual details, and spatial relationships. Their eyesight is fine, but they may have trouble processing what they see; for example, a student might find it hard to follow a set of instructions demonstrated by a teacher.

Some children with NVLD have trouble in other areas. They may have poor motor skills and problems with coordination; for example, learning to ride a bike can be very difficult for a child with NVLD. They may have trouble socializing with other children because they do not pick up on nonverbal social cues such as tone of voice and body language, or may make a comment that is inappropriate in a specific context. Children with NVLD tend to be easily frustrated and upset. Any new situation can make them anxious because they have more difficulty adjusting to it.

There are many other subtypes of learning disabilities, but verbal and nonverbal learning disabilities are the two main categories. Because many aspects of speaking, listening, reading, writing, and arithmetic overlap and build on the same brain capabilities, it is not unusual for someone to have more than one disorder. For example, most disorders that hinder the ability to understand language will also interfere with learning to read, spell, and write.

Attention deficit hyperactivity disorder * , or ADHD, can also interfere with learning. Children with ADHD often have difficulty focusing on any one task for an extended period of time. Children with attention problems may have learning problems, but attention deficits are not classified as specific learning disabilities. More than half of children with ADHD also have learning disabilities.

Parents and teachers are usually the first to notice signs of a possible learning disability. A very young child might not speak or listen as well as other children their age, or they might have trouble with a game's directions or other activities that other children complete with ease. The classroom teacher may notice persistent difficulties in reading, writing, or mathematical calculations.

The first step in diagnosing a learning disability is to rule out any other possible causes, such as vision or hearing problems or some other medical condition. Once a doctor makes sure that physical problems are not causing the disability, the child may be evaluated by a psychologist * who specializes in learning disabilities. Diagnosing a learning disorder often takes time. The psychologist usually takes a careful history of symptoms, interviews the child, and gives certain tests that compare the child's level of ability to what is considered appropriate for a person of his or her age and intelligence.

Why certain children develop learning disabilities and others do not is a mystery. Researchers have speculated that learning disabilities may be traced to differences in early brain development that occur before or after birth. During brain development, a few all-purpose cells must grow into a complex organ made of billions of specialized interconnected nerve cells called neurons (NUR-ons). Researchers are investigating possible causes for differences or disruptions in brain development that include the following:

Because some learning disabilities tend to run in families, researchers have been exploring whether and how learning differences may be inherited.

Because children with learning disabilities typically have normal or abovenormal intelligence, they often can find ways to learn in spite of the disorder. They may need to attend special school programs for the learning disabled, or to work with a learning specialist several hours each week while attending regular classes.

Special education teachers can help plan what is called an Individualized Education Program, or IEP, for a learning-disabled child. This plan outlines the specific skills the child needs to develop, as well as appropriate learning activities that build on the child's strengths and work around his or her difficulties. For example, a student with dyslexia might be encouraged to listen to audiobooks for English class, and a student with a writing disorder might take notes or complete an assignment using a laptop computer.

Children with learning disabilities often need emotional support because they may see themselves as stupid. They may withdraw from their classmates at school or even get into trouble because they are frustrated when learning is difficult for them. These children and their families can often benefit by working with a trained counselor or support group.

See also Attention Deficit Hyperactivity Disorder (ADHD) • Autism Spectrum Disorder • Brain Injuries • Disability • Environmental Diseases: Overview • Fetal Alcohol Spectrum Disorders (FASD) • Intellectual Disability • Memory and Amnesia • Testing and Evaluation • Trauma

* attention deficit hyperactivity disorder or ADHD, is a condition that makes it hard for a person to pay attention, sit still, or think before acting.

* psychologist (sy-KOL-uh-jist) is a mental health professional who can do psychological testing and provide mental health counseling.