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 expressive language disorder
Developmental receptive language disorder
Developmental Articulation 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 are often outgrown or successfully treated with speech therapy.

Developmental Expressive Language Disorder

Some children with language impairments have problems expressing them selves in speech. Their disorder is called, therefore, a developmental expressive language disorder. This disorder can take many forms. For example, a 4-year-old who speaks only in two-word phrases and a 6-year-old who can't answer simple questions have an expressive language disorder.

Developmental Receptive Language Disorder

Some people have trouble understanding certain aspects of speech. There's a toddler who doesn't respond to his name, a preschooler who hands you a bell when you asked for a ball, or a worker who consistently can't follow simple directions. Their hearing is fine, but they can't 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. [Of course, in preschoolers, some misuse of sounds, words, or grammar is a normal part of learning to speak. It's only when these problems persist that there is any cause for concern.]

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 writing disorder
Developmental arithmetic disorder
Developmental Reading 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. When you think of what is involved in the "three R's" -reading, 'riting, and 'rithmetic- it's astounding that most of us do learn them. Consider that to read, you must simultaneously:

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

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. Some children have problems sounding out words, while others have trouble with rhyming games, such as rhyming "cat" with "bat." Yet, scientists have found these skills fundamental to learning to read. Fortunately, remedial reading specialists have developed techniques that can help many children with dyslexia acquire these skills.

However, these 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, 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, aligning numbers, and understanding abstract concepts like place value and fractions. Any of these may be difficult for children with developmental arithmetic disorders, also called dyscalculia. Problems with number 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's not surprising that people can be diagnosed as having more than one area of learning disability. For example, the ability to understand language underlies learning to speak.Therefore, any disorder that hinders the ability to understand language will also interferewith 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 Differences

There are also other 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 disorder.

[Source: National Institutes of Health, 1993.]