Learning disabilities can be categorized by either the type of
information processing affected by the disability or by the specific difficulties caused by a processing deficit.
By stage of information processing Learning disabilities fall into broad categories based on the four stages of information processing used in learning: input, integration, storage, and output. Many learning disabilities are a compilation of a few types of abnormalities occurring at the same time, as well as with social difficulties and
emotional or behavioral disorders. • Input: This is the information perceived through the senses, such as
visual and
auditory perception. Difficulties with visual perception can cause problems with recognizing the shape, position, or size of items seen. There can be problems with
sequencing, which can relate to deficits with processing time intervals or temporal perception. Difficulties with auditory perception can make it difficult to screen out competing sounds in order to focus on one of them, such as the sound of the teacher's voice in a classroom setting. Some children appear to be unable to process tactile input. For example, they may seem insensitive to pain or dislike being touched. • Integration: This is the stage during which perceived input is interpreted, categorized, placed in a sequence, or related to previous learning. Students with problems in these areas may be unable to tell a story in the correct sequence, unable to memorize sequences of information such as the days of the week, able to understand a new concept but be unable to generalize it to other areas of learning, or able to learn facts but be unable to put the facts together to see the "big picture." A poor vocabulary may contribute to problems with comprehension. • Storage: Problems with memory can occur with
short-term or
working memory, or with
long-term memory. Most memory difficulties occur with one's short-term memory, which can make it difficult to learn new material without more repetitions than usual. Difficulties with
visual memory can impede learning to spell. • Output: Information comes out of the brain either through words, that is, language output, or through muscle activity, such as gesturing, writing or drawing. Difficulties with language output can create problems with spoken language. Such difficulties include answering a question on demand, in which one must retrieve information from storage, organize one's thoughts, and put the thoughts into words before speaking. It can also cause trouble with written language for the same reasons. Difficulties with motor abilities can cause problems with gross and fine motor skills. People with gross motor difficulties may be clumsy, that is, they may be prone to stumbling, falling, or bumping into things. They may also have trouble running, climbing, or learning to ride a bicycle. People with fine motor difficulties may have trouble with handwriting, buttoning shirts, or tying shoelaces.
By function impaired Deficits in any area of information processing can manifest in a variety of specific learning disabilities (SLD). It is possible for an individual to have more than one of these difficulties. This is referred to as comorbidity or co-occurrence of learning disabilities. In the UK, the term
dual diagnosis is often used to refer to co-occurrence of learning difficulties.
Specific Learning Disorder (DSM-5-TR) and Developmental learning disorder (ICD-11: 6A03) DSM-5-TR defines specific learning disorder as difficulties learning and using academic skills, substantially below the expected age, beginning during school-age years and has three specifiers for the type of impairment seen. ICD-11 defines developmental learning disorder similarly and has the same three specifiers. •
With impairment in reading (DSM-5-TR: F81.0, ICD-11: 6A03.0) Learning difficulties are manifested in impairments in reading skills such as word reading accuracy, reading fluency or reading comprehension. Previously termed 'reading disorder', this is the most common learning disability. Of all students with specific learning disabilities, 70–80% have deficits in reading. The term
developmental dyslexia is often used as a synonym for reading disability; however, many researchers assert that there are different types of reading disabilities, of which dyslexia is one. A reading disability can affect any part of the reading process, including difficulty with accurate or fluent word recognition, or both, word decoding, reading rate, prosody (oral reading with expression), and reading comprehension. Before the term
dyslexia came to prominence, this learning disability used to be known as
word blindness. Common indicators of reading disability include difficulty with phonemic awareness—the ability to break up words into their component sounds, and difficulty with matching letter combinations to specific sounds (sound-symbol correspondence). •
With impairment in written expression (DSM-5-TR: F81.81, ICD-11: 6A03.1) Learning difficulties are manifested in impairments in writing skills such as spelling accuracy, grammar and punctuation accuracy, or organization and cohesion of ideas in writing. Previously termed 'disorder of written expression'.Individuals with a diagnosis of a disorder of written expression typically have a combination of difficulties in their abilities with written expression as evidenced by grammatical and punctuation errors within sentences, poor paragraph organization, multiple spelling errors, and excessively poor penmanship. A disorder in spelling or handwriting without other difficulties of written expression do not generally qualify for this diagnosis. If poor handwriting is due to an impairment in the individuals' motor coordination, a diagnosis of
developmental coordination disorder should be considered. By a number of organizations, the term
dysgraphia has been used as an overarching term for all disorders of written expression. •
With impairment in mathematics (DSM-5-TR: F81.2, ICD-11: 6A03.2) Sometimes called
dyscalculia, a math disability involves difficulties such as learning math concepts (such as quantity, place value, and time), difficulty memorizing math facts, difficulty organizing numbers, and understanding how problems are organized on the page. Dyscalculics are often referred to as having poor
number sense.
Non ICD-10/DSM •
Nonverbal learning disability: Nonverbal learning disabilities often manifest in motor clumsiness, poor visual-spatial skills, problematic social relationships, difficulty with mathematics, and poor organizational skills. These individuals often have specific strengths in the verbal domains, including early speech, large vocabulary, early reading and spelling skills, excellent rote memory and auditory retention, and eloquent self-expression. • Disorders of speaking and listening: Difficulties that often co-occur with learning disabilities include difficulty with memory, social skills and
executive functions (such as organizational skills and time management). ==Management==