Childhood learning disabilities
Unlike other disabilities, such as paralysis or blindness, a learning disability (LD) is a hidden handicap. A learning disability does not disfigure or leave visible signs that would invite others to be understanding or offer support.
LD is a disorder that affects people's ability to either interpret what they see and hear or to link information from different parts of the brain. These limitations can show up in many ways as specific difficulties with spoken and written language, coordination, self-control, or attention. Such difficulties extend to schoolwork and can impede learning to read or write, or to do math.
Learning disabilities can be lifelong conditions that, in some cases, affect many parts of a person's life like school or work, daily routines, family life, and sometimes even friendships and play. In some people, many overlapping learning disabilities may be apparent. Other people may have a single, isolated learning problem that has little impact on other areas of their lives.
Types of learning disabilities
Learning disability is not a diagnosis in the same sense as chickenpox or mumps. Chickenpox and mumps imply a single, known cause with a predictable set of symptoms. Rather, learning disability is a broad term that covers a pool of possible causes, symptoms, treatments, and outcomes. Partly because learning disabilities can show up in so many forms, it is difficult to diagnose or to pinpoint the causes. And no one knows of a pill or remedy that will cure them.
Not all learning problems are necessarily learning disabilities. Many children are simply slower in developing certain skills. Because children show natural differences in their rate of development, sometimes what seems to be a learning disability may simply be a delay in maturation. To be diagnosed as a learning disability, specific criteria must be met.
Learning disabilities can be divided into three broad categories:
- Developmental speech and language disorders
- Academic skills disorders
- Other, a catch-all that includes certain coordination disorders and learning handicaps not covered by the other terms
Each of these categories includes a number of more specific disorders.
Developmental Speech and Language Disorders
Speech and language problems are often the earliest indicators of a learning disability. People with developmental speech and language disorders have difficulty producing speech sounds, using spoken language to communicate, or understanding what other people say. Depending on the problem, the specific diagnosis may be:
Developmental Articulation Disorder :
- Developmental articulation disorder
- Developmental expressive language disorder
- Developmental receptive language disorder
Children with this disorder may have trouble controlling their rate of speech. Or they may lag behind playmates in learning to make speech sounds. Developmental articulation disorders are common. They appear in at least 10 percent of children younger than age 8. Fortunately, articulation disorders can often be outgrown or successfully treated with speech therapy.
Developmental Expressive Language Disorder:
Some children with language impairments have problems expressing themselves in speech. Their disorder is called, therefore, a developmental expressive language disorder. An expressive language disorder can take other forms. A 4-year-old who speaks only in two-word phrases and a 6-year-old who can't answer simple questions also have an expressive language disability.
Developmental Receptive Language Disorder :
Some people have trouble understanding certain aspects of speech. It is as if their brains are set to a different frequency and the reception is poor. Their hearing is fine, but they cannot make sense of certain sounds, words, or sentences they hear. They may even seem inattentive. These people have a receptive language disorder. Because using and understanding speech are strongly related, many people with receptive language disorders also have an expressive language disability.
Academic Skills Disorders
Students with academic skills disorders are often years behind their classmates in developing reading, writing, or arithmetic skills. The diagnoses in this category include:
Developmental Reading Disorder :
- Developmental reading disorder
- Developmental writing disorder
- Developmental arithmetic disorder
This type of disorder, also known as dyslexia, is quite widespread. In fact, reading disabilities affect 2 to 8 percent of elementary school children.
- Focus attention on the printed marks and control eye movements across the page
- Recognize the sounds associated with letters
- Understand words and grammar
- Build ideas and images
- Compare new ideas to what you already know
- Store ideas in memory
Such mental juggling requires a rich, intact network of nerve cells that connect the brain's centers of vision, language, and memory.
A person can have problems in any of the tasks involved in reading. However, scientists found that a significant number of people with dyslexia share an inability to distinguish or separate the sounds in spoken words. Fortunately, remedial reading specialists have developed techniques that can help many children with dyslexia acquire these skills.
However, there is more to reading than recognizing words. If the brain is unable to form images or relate new ideas to those stored in memory, the reader can't understand or remember the new concepts. So other types of reading disabilities can appear in the upper grades when the focus of reading shifts from word identification to comprehension.
Developmental Writing Disorder:
Writing, too, involves several brain areas and functions. The brain networks for vocabulary, grammar, hand movement, and memory must all be in good working order. So a developmental writing disorder may result from problems in any of these areas. For example, Dennis, who was unable to distinguish the sequence of sounds in a word, had problems with spelling. A child with a writing disability, particularly an expressive language disorder, might be unable to compose complete, grammatical sentences.
Developmental Arithmetic Disorder :
Arithmetic involves recognizing numbers and symbols, memorizing facts such as the multiplication table, aligning numbers, and understanding abstract concepts like place value and fractions. Any of these may be difficult for children with developmental arithmetic disorders. Problems with numbers or basic concepts are likely to show up early. Disabilities that appear in the later grades are more often tied to problems in reasoning.
Many aspects of speaking, listening, reading, writing, and arithmetic overlap and build on the same brain capabilities. So it is not surprising that people can be diagnosed as having more than one area of learning disability. Any disorder that hinders the ability to understand language will also interfere with the development of speech, which in turn hinders learning to read and write. A single gap in the brain's operation can disrupt many types of activity.
"Other" Learning Disabilities
The DSM also lists additional categories, such as "motor skills disorders" and "specific developmental disorders not otherwise specified." These diagnoses include delays in acquiring language, academic, and motor skills that can affect the ability to learn, but do not meet the criteria for a specific learning disability. Also included are coordination disorders that can lead to poor penmanship, as well as certain spelling and memory disorders.
Some children and adults who have attention disorders appear to daydream excessively. And once you get their attention, they are often easily distracted.
In a large proportion of affected children, mostly boys, the attention deficit is accompanied by hyperactivity. These children's problems are usually hard to miss. Because of their constant motion and explosive energy, hyperactive children often get into trouble with parents, teachers, and peers.
By adolescence, physical hyperactivity usually subsides into fidgeting and restlessness. But the problems with attention and concentration often continue into adulthood. At work, adults with ADHD often have trouble organizing tasks or completing their work. They don't seem to listen to or follow directions. Their work may be messy and appear careless.
Attention disorders, with or without hyperactivity, are not considered learning disabilities in themselves. However, because attention problems can seriously interfere with school performance, they often accompany academic skills disorders.
Causes of Learning Disabilities
Mental health professionals stress that since no one knows what causes learning disabilities, it does not help parents to look backward to search for possible reasons. There are too many possibilities to pin down the cause of the disability with certainty. It is far more important for the family to move forward in finding ways to get the fight help.
Once, scientists thought that all learning disabilities were caused by a single neurological problem. But research has helped us see that the causes are more diverse and complex. New evidence seems to show that most learning disabilities do not stem from a single, specific area of the brain, but from difficulties in bringing together information from various brain regions.
Today, a leading theory is that learning disabilities stem from subtle disturbances in brain structures and functions. Some scientists believe that, in many cases, the disturbance begins before birth.
Errors in Fetal Brain Development
Throughout pregnancy, the fetal brain develops from a few all-purpose cells into a complex organ made of billions of specialized, interconnected nerve cells called neurons. During this amazing evolution, things can go wrong that may alter how the neurons form or interconnect.
In the early stages of pregnancy, the brain stem forms. It controls basic life functions such as breathing and digestion. Later, a deep ridge divides the cerebrum which is the thinking part of the brain - into two halves, a right and left hemisphere. Finally, the areas involved with processing sight, sound, and other senses develop, as well as the areas associated with attention, thinking, and emotion.
As new cells form, they move into place to create various brain structures. Nerve cells rapidly grow to form networks with other parts of the brain. These networks are what allow information to be shared among various regions of the brain.
Throughout pregnancy, this brain development is vulnerable to disruptions. If the disruption occurs early, the fetus may die, or the infant may be born with widespread disabilities and possibly mental retardation. If the disruption occurs later, when the cells are becoming specialized and moving into place, it may leave errors in the cell makeup, location, or connections. Some scientists believe that these errors may later show up as learning disorders.
Other Factors That Affect Brain Development
Some of these studies are examining how genes, substance abuse, pregnancy problems, and toxins may affect the developing brain.
Genetic Factors :
The fact that learning disabilities tend to run in families indicates that there may be a genetic link. For example, children who lack some of the skills needed for reading, such as hearing the separate sounds of words, are likely to have a parent with a related problem. However, a parent's learning disability may take a slightly different form in the child. A parent who has a writing disorder may have a child with an expressive language disorder. For this reason, it seems unlikely that specific learning disorders are inherited directly. Possibly, what is inherited is a subtle brain dysfunction that can in turn lead to a learning disability.
Some learning difficulties may actually stem from the family environment. For example, parents who have expressive language disorders might talk less to their children, or the language they use may be distorted. In such cases, the child lacks a good model for acquiring language and therefore, may seem to be learning disabled.
Tobacco, Alcohol, and Other Drug Use :
Many drugs taken by the mother pass directly to the fetus. Research shows that a mother's use of cigarettes, alcohol, or other drugs during pregnancy may have damaging effects on the unborn child.
Scientists have found that mothers who smoke during pregnancy may be more likely to bear smaller babies. This is a concern because small newborns, usually those weighing less than 5 pounds, tend to be at risk for a variety of problems, including learning disorders.
Alcohol also may be dangerous to the fetus developing brain. It appears that alcohol may distort the developing neurons. Heavy alcohol use during pregnancy has been linked to fetal alcohol syndrome, a condition that can lead to low birth weigh, intellectual impairment, hyperactivity, and certain physical defects. Any alcohol use during pregnancy, however, may influence the child's development and lead to problems with learning, attention, memory, or problem solving.
Drugs such as cocaine, especially in its smokable form known as crack--seem to affect the normal development of brain receptors. These brain cell parts help to transmit incoming signals from our skin, eyes, and ears, and help regulate our physical response to the environment. Because children with certain learning disabilities have difficulty understanding speech sounds or letters, some researchers believe that learning disabilities, as well as ADHD, may be related to faulty receptors. Current research points to drug abuse as a possible cause of receptor damage.
Problems During Pregnancy or Delivery :
Other possible causes of learning disabilities involve complications during pregnancy. In some cases, the mother's immune system reacts to the fetus and attacks it as if it were an infection. This type of disruption seems to cause newly formed brain cells to settle in the wrong part of the brain. Or during delivery, the umbilical cord may become twisted and temporarily cut off oxygen to the fetus. This, too, can impair brain functions and lead to LD.
Toxins in the Child's Environment :
New brain cells and neural networks continue to be produced for a year or so after the child is born. These cells are vulnerable to certain disruptions, also.
Researchers are looking into environmental toxins that may lead to learning disabilities, possibly by disrupting childhood brain development or brain processes. Cadmium and lead, both prevalent in the environment, are becoming a leading focus of neurological research. Cadmium, used in making some steel products, can get into the soil, then into the foods we eat. Lead was once common in paint and gasoline, and is still present in some water pipes. In addition, there is growing evidence that learning problems may develop in children with cancer who had been treated with chemotherapy or radiation at an early age. This seems particularly true of children with brain tumors who received radiation to the skull.
Are Learning Disabilities Related to Differences in the Brain?
In comparing people with and without learning disabilities, scientists have observed certain differences in the structure and functioning of the brain. For example, new research indicates that there may be variations in the brain structure called the planum temporale, a language-related area found in both sides of the brain. In people with dyslexia, the two structures were found to be equal in size. In people who are not dyslexic, however, the left planum temporale was noticeably larger. Some scientists believe reading problems may be related to such differences.
With more research, scientists hope to learn precisely how differences in the structures and processes of the brain contribute to learning disabilities, and how these differences might be treated or prevented.
How it is diagnosed
Learning disability is defined as a significant gap between a person's intelligence and the skills the person has achieved at each age. This means that a severely retarded 10-year-old who speaks like a 6-year-old probably doesn't have a language or speech disability.
Learning disorders may be informally flagged by observing significant delays in the child's skill development. A 2-year delay in the primary grades is usually considered significant. For older students, such a delay is not as debilitating, so learning disabilities are not usually suspected unless there is more than a 2-year delay. Actual diagnosis of learning disabilities, however, is made using standardized tests that compare the child's level of ability to what is considered normal development for a person of that age and intelligence.
Test outcomes depend not only on the child's actual abilities, but on the reliability of the test and the child's ability to pay attention and understand the questions. Children with poor attention or hyperactivity, may score several points below their true level of ability. Testing a child in an isolated room can sometimes help the child concentrate and score higher.
Each type of LD is diagnosed in slightly different ways. To diagnose speech and language disorders, a speech therapist tests the child's pronunciation, vocabulary, and grammar and compares them to the developmental abilities seen in most children that age. A psychologist tests the child's intelligence. A physician checks for any ear infections, and an audiologist may be consulted to rule out auditory problems. If the problem involves articulation, a doctor examines the child's vocal cords and throat.
ADHD is diagnosed by checking for the long-term presence of specific behaviors, such as considerable fidgeting, losing things, interrupting, and talking excessively. Other signs include an inability to remain seated, stay on task, or take turns. A diagnosis of ADHD is made only if the child shows such behaviors substantially more than other children of the same age.
What Are the Education Options?
Although obtaining a diagnosis is important, even more important is creating a plan for getting the right help. Because LD can affect the child and family in so many ways, help may be needed on a variety of fronts: educational, medical, emotional, and practical.
In most ways, children with learning disabilities are no different from children without these disabilities. At school, they eat together and share sports, games, and after-school activities. But since children with learning disabilities do have specific learning needs, most public schools provide special programs.
Schools typically provide special education programs either in a separate all-day classroom or as a special education class that the student attends for several hours each week. Some parents hire trained tutors to work with their child after school. If the problems are severe, some parents choose to place their child in a special school for the learning disabled.
The specialist should be able to explain things in terms that the parents can understand. Planning a special education program begins with systematically identifying what the student can and cannot do. The specialist looks for patterns in the child's gaps. If there is a problem with handwriting, are there other motor delays? Are there any consistent problems with memory?
Special education teachers also identify the types of tasks the child can do and the senses that function well. By using the senses that are intact and bypassing the disabilities, many children can develop needed skills. These strengths offer alternative ways the child can learn.
An individualized, skill-based approach, like the approach used by speech and language therapists - often succeeds in helping where regular classroom instruction fails. Therapy for speech and language disorders focuses on providing a stimulating but structured environment for heating and practicing language patterns. For example, the therapist may help a child who has an articulation disorder to produce specific speech sounds. During an engaging activity, the therapist may talk about the toys, then encourage the child to use the same sounds or words. In addition, the child may watch the therapist make the sound, feel the vibration in the therapist's throat, then practice making the sounds before a mirror.
Researchers are also investigating nonstandard teaching methods. Some create artificial learning conditions that may help the brain receive information in nonstandard ways. For example, in some language disorders, the brain seems abnormally slow to process verbal information. Scientists are testing whether computers that talk can help teach children to process spoken sounds more quickly.
Is Medication Available?
For nearly six decades, many children with attention disorders have benefited from being treated with medication. Three drugs, Ritalin (methylphenidate), Dexedrine (dextroamphetamine), and Cylert (pemoline), have been used successfully. Although these drugs are stimulants in the same category as speed and diet pills, they seldom make children high or more jittery. Rather, they temporarily improve children's attention and ability to focus. They also help children control their impulsiveness and other hyperactive behaviors.
The effects of medication are most dramatic in children with ADHD. Shortly after taking the medication, they become more able to focus their attention. They become more ready to learn. Studies by scientists and other researchers have shown that at least 90 percent of hyperactive children can be helped by either Ritalin or Dexedrine. If one medication does not help a hyperactive child to calm down and pay attention in school, the other medication might.
The drugs are effective for 3 to 4 hours and move out of the body within 12 hours. The child's doctor or a psychiatrist works closely with the family and child to carefully adjust the dosage and medication schedule for the best effect. Typically, the child takes the medication so that the drug is active during peak school hours, such as when reading.
In the past few years, researchers have tested these drugs on adults who have attention disorders. Just as in children, the results show that low doses of these medications can help reduce distractibility and impulsivity in adults. Use of these medications has made it possible for many severely disordered adults to organize their lives, hold jobs, and care for themselves.
In trying to do everything possible to help their children, many parents have been quick to try new treatments. Most of these treatments sound scientific and reasonable, but a few are pure quackery. Many are developed by reputable doctors or specialists--but when tested scientifically, cannot be proven to help. Following are types of therapy that have not proven effective in treating the majority of children with learning disabilities or attention disorders:
- Colored lenses
- Special diets
- Sugar-free diets
- Body stimulation or manipulation
Although scientists hope that brain research will lead to new medical interventions and drugs, at present there are no medicines for speech, language, or academic disabilities.
Can Learning Disabilities Be Outgrown or Cured?
Even though most people don't outgrow their brain dysfunction, people do learn to adapt and live fulfilling lives. Even though a learning disability doesn't disappear, given the right types of educational experiences, people have a remarkable ability to learn. The brain's flexibility to learn new skills is probably greatest in young children and may diminish somewhat after puberty. This is why early intervention is so important. Nevertheless, we retain the ability to learn throughout our lives.
Even though learning disabilities cannot be cured, there is still cause for hope. Because certain learning problems reflect delayed development, many children do eventually catch up. Of the speech and language disorders, children who have an articulation or an expressive language disorder are the least likely to have long-term problems. Despite initial delays, most children do learn to speak.
For people with dyslexia, the outlook is mixed. But an appropriate remedial reading program can help learners make great strides.
With age, and appropriate help from parents and clinicians, children with ADHD become better able to suppress their hyperactivity and to channel it into more socially acceptable behaviors.