Disorders usually first diagnosed in
infancy, childhood, or adolescence.
Learning Disabilities--

In the United States and Canada, the term learning disability (LD) refers to a group of disorders that affect a broad
range of academic and functional skills including the ability to speak, listen, read, write, spell, reason and organize

A learning disability is not indicative of low intelligence. People with learning disabilities sometimes have difficulty
achieving at his or her intellectual level because of a deficit in one or more of the ways the brain processes


The National Joint Committee for Learning Disabilities (NJCLD)[1] defines the term learning disability as "... a
heterogeneous group of disorders manifested by significant difficulties in the acquisition and use of listening,
speaking, reading, writing, reasoning or mathematical abilities. These disorders are intrinsic to the individual and
presumed to be due to Central Nervous System Dysfunction. Even though a learning disability may occur
concomitantly with other handicapping conditions (e.g. sensory impairment, mental retardation, social and emotional
disturbance) or environmental influences (e.g. cultural differences, insufficient/inappropriate instruction,
psychogenic factors) it is not the direct result of those conditions or influences."

The term “learning disability” was apparently first used and defined by Kirk [2]. The term referred to a discrepancy
between a child’s apparent capacity to learn and his or her level of achievement.

Types of learning disabilities

Learning disabilities can be categorized either by the type of information processing that is affected or by the
specific difficulties caused by a processing deficit.

Information Processing Deficits

The National Dissemination Center for Children with Disabilities (NICHY) [3] states that learning disabilities fall into
broad categories based on the four stages of information processing used in learning: input, integration, storage,
and output.

* 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 and 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. 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 in the area of short-term memory, which can make it difficult to learn new material without many
more repetitions than is 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, for
example, answering a question on demand, in which one must retrieve information from storage, organize our
thoughts, and put the thoughts into words before we speak. 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 small motor difficulties may have
trouble buttoning shirts, tying shoelaces, or with handwriting.

Specific learning disabilities

Deficits in any area of information processing can manifest in a variety of specific learning disabilities.

* Reading disability (ICD-10 and DSM-IV codes: F81.0/315.00)

The most common learning disability. Of all students with specific learning disabilities, 70%-80% have deficits in
reading. The term "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 and/or fluent word recognition, word decoding, reading rate,
prosody (oral reading with expression), and reading comprehension.

Common indicators of reading disability include difficulty with phonemic awareness -- the ability to blend sounds into
words or break up words into their component sounds, and difficulty with matching letters or letter combinations to
specific sounds (sound-symbol correspondence).

* Writing disability (ICD-10 and DSM-IV codes F81.1/315.2)

Speech and language disorders can also be called Dysphasia/aphasia (coded F80.0-F80.2/315.31 in ICD-10 and

Impaired written language ability may include impairments in handwriting, spelling, organization of ideas, and
composition. The term "dysgraphia" is often used as an overarching term for all disorders of written expression.
Others, such as the International Dyslexia Association, use the term "dysgraphia" exclusively to refer to difficulties
with handwriting.

* Math disability (ICD-10 and DSM-IV codes F81.2-3/315.1)

Sometimes called dyscalculia, a math disability can cause such difficulties 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.

* Nonverbal learning disability [this disorder is not listed in the ICD-10]

Nonverbal learning disabilities often manifest in motor clumsiness, poor visual-spatial skills, problematic social
relationships, difficulty with math, and poor organizational skills. These indivduals 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. [4]

* Dyspraxia

Sometimes called motor planning, dyspraxia refers to a variety of difficulties with motor skills. Dyspraxia can cause
difficulty with single step tasks such as combing hair or waving goodbye, multi-step tasks like brushing teeth or
getting dressed, or with establishing spatial relationships such as being able to accurately position one object in
relation to another.

* 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).


The presence of a learning disability is sometimes suspected by a child's parents long before problems are seen at
school. However, the issues typically become visible when a child begins having difficulty at school. Difficulty
learning to read is often one of the first signs that a learning disability is present.

Learning disabilities are often identified by school psychologists, clinical psychologists, and neuropsychologists
through a combination of intelligence testing, academic achievement testing, classroom performance, and social
interaction and aptitude. Other areas of assessment may include perception, cognition, memory, attention, and
language abilities. The resulting information is used to determine whether a child is achieving at his or her potential.

The DSM-IV, and many school systems and government programs have defined learning disabilities on the basis of
a discrepancy between IQ scores and achievement scores. Although the discrepancy model has dominated the
school system for many years, there has been substantial criticism of this approach (eg, Aaron, 1995, Flanagan and
Mascolo, 2005) among researchers. Recent research has provided little evidence that a discrepancy between
formally-measured IQ and achievement is a clear indicator of LD (Fletcher, 2003). Furthermore, diagnosing on the
basis of a discrepancy does not predict the effectiveness of treatment. Low academic achievers who do not have a
discrepancy with IQ (ie their IQ scores are also low) appear to benefit from treatment just as much as low academic
achievers who do have a discrepancy with IQ (ie their IQ scores are higher).

Much current research has focused on a treatment-oriented diagnostic process known as response to intervention
(RTI). Researcher recommendations for implementing such a model include early screening for all students, placing
students having difficulty in research-based early intervention programs, and closely monitoring the progress of
identified students to determine whether increasingly intense intervention results in adequate progress (Fletcher,
2003). Those who do not respond adequately to intervention can then be referred for further assistance through
special education. A primary benefit of such a model is that it would not be necessary to wait for a child to be
sufficiently far behind to qualify for assistance (Lyon, et al, 2001). This may enable more children to receive
assistance before experiencing significant failure, which may in turn result in fewer children who need intensive and
expensive special education services.

Treatment and Intervention

Poor academic achievement can be addressed with a variety of interventions. Although the underlying processing
difficulty is usually considered to be a lifelong disorder, academic skills themselves can be improved with targeted
interventions. Some (adjustments, equipment and assistants) are designed to accommodate or help compensate for
the disabilities while others (specialized instruction) are intended to make improvements in the weak areas. Practice
is a particularly important component in developing competence, regardless of the starting point. Children who start
out with a weakness in a basic skill, such as reading, may miss out on the necessary practice because of the need
to catch up with their chronological age peers. Thus a small weakness can snowball into a larger problem.

Interventions include:

* Mastery Model:
o Learners work at their own level of mastery.
o Practice
o Gain fundamental skills before moving onto the next level
+ Note: this approach is most likely to be used with adult learners or outside the mainstream school system.

* Direct Instruction: [5]
o Highly structured, intensive instruction
o Emphasizes carefully planned lessons for small learning increments
o Scripted lesson plans
o Rapid-paced interaction between teacher and students
o Correcting mistakes immediately
o Achievement-based grouping
o Frequent progress assessments

* Classroom adjustments:
o Special seating assignments
o Alternative or modified assignments
o Modified testing procedures

* Special equipment:
o Electronic spellers and dictionaries
o Word processors
o Talking calculators
o Books on tape

* Classroom assistants:
o Note-takers
o Readers
o Proofreaders

* Special Education:
o Prescribed hours in a special class
o Placement in a special class
o Enrollment in a special school for learning disabled students

Sternberg [6] has argued that early remediation can greatly reduce the number of children meeting diagnostic
criteria for learning disabilities. He has also suggested that the focus on learning disabilities and the provision of
accommodations in school fails to acknowledge that people have a range of strengths and weaknesses, and places
undue emphasis on academic success by insisting that people should receive additional support in this arena but
not in music or sports.

Causes and Risk Factors

The causes for learning disabilities are not well understood, and sometimes there is no apparent cause for a
learning disability. However, some causes of neurological impairments include:

* Heredity -- Learning disabilities often run in the family.
* Problems during pregnancy and birth -- Learning disabilities can result from anomalies in the developing brain,
illness or injury, fetal exposure to alcohol or drugs, low birth weight, oxygen deprivation, or by premature or
prolonged labor.
* Accidents after birth -- Learning disabilities can also be caused by head injuries, malnutrition, or by toxic exposure
(such as heavy metals or pesticides).

Impact on Affected Individuals

Individuals with a learning disability may isolate themselves from society as they may feel:

* Ashamed of the types of difficulties they struggle with, such as poor literacy skills, attention or memory difficulties
* Fear of failure, criticism, ridicule or rejection
* Fear that others may think that they are stupid or incapable
* Ashamed that they are unable to read or that they have poor handwriting
* Left out of every day discussions due to lack of understanding
* Depressed
* Alone

Impact on society

Statistical and demographic studies show that society pays a high cost for untreated learning disabilities because of
the disproportionate number of individuals with LD who receive welfare, who commit crimes, who go to juvenile
courts, who are held in a juvenile detention facility, and who go to prison.


* According to a study conducted by the Center for Law and Social Policy, 25%-35% of former participants in a
federal welfare-to-work program had learning disabilities, 85% of whom had not been identified as learning disabled
by the public schools. [7]

* The New York State Rehabilitation Association estimates that 25%-40% of individuals with learning disabilities
receive public assistance. [8]

* Rhode Island found that 21 percent of a sample of new welfare applicants between May 1997 and February 1998
had a learning disability. [9]

Gender issues

* Research shows that as many girls as boys have learning disabilities, but that girls are less aggressive and
outspoken in elementary school, resulting in girls who have learning disabilities unidentified and untreated. However,
according to the National Institute for Literacy, about three boys are determined to have a learning disability for
every girl who is so determined. Dr. Reid Lyon of the National Institutes of Health explains that girls display fewer
disruptive behaviors in elementary school than boys, so girls with learning disabilities are often unnoticed and
untreated. [10]

* The failure of some schools to identify learning disabilities among young girls is one explanation researchers offer
for the significant number of welfare recipients with learning disabilities. According to the an issues brief prepared by
the National Governors’ Association, the significant number of welfare recipients with learning disabilities can be
explained in part by the failure of some schools to identify learning disabilities among young girls. [11]

Crime and prison population

* Approximately 80% of prison inmates are reported to be functionally illiterate. [12] [13] [14] These inmates cannot
read or write well enough to find an intersection on a map, apply for a Social Security card, or write a simple letter.

* Researchers [16] found that a majority of inmates who were reading below high school levels showed signs of
moderate to severe decoding and word recognition problems. That is, they had dyslexia, a reading disability.

* Approximately 40% of youth held in detention facilities have some form of learning disability, such as dyslexia. [17]

Contrast with other conditions

People with an IQ lower than 70 are usually characterized as having mental retardation (MR), mental deficiency, or
cognitive impairment and are not included under most definitions of learning disabilities, because their learning
difficulties are related directly to their low IQ scores.

Attention-deficit hyperactivity disorder (ADHD) is often studied in connection with learning disabilities, but it is not
actually included in the standard definitions of learning disabilities. An individual with ADHD may struggle with
learning, but he or she can often learn adequately once successfully treated for the ADHD. A person can have
ADHD but not learning disabilities or have learning disabilities without having ADHD. The conditions can co-occur
(see Comorbidity). In order to understand the difference, imagine that someone with a learning disability is affected
in only one or a few areas. However, people with ADHD are often affected in all areas. ADHD is also caused by
chemical imbalances rather than the physical differences in the brain that cause Dyslexia.

Some research is beginning to make a case for ADHD's being included in the definition of LDs, since it is being
shown to have a strong impact on "executive functions" required for learning (planning, organization, etc). This has
not as yet affected any official definitions.


1. ^ 1981; 1985
2. ^ 1962, cited in Streissguth, Bookstein, Sampson, & Barr, 1993, p.144
3. ^ National Dissemination Center for Children with Disabilities (NICHY), 2004. [1]. Accessed May 11, 2007.
4. ^ Lerner, Janet (2000). Learning Disabilities: Theories, Diagnosis and Teaching Strategies. Eighth edition. Houghton Mifflin.
5. ^ National Institute for Direct Instruction www.nifdi.org. Accessed May 23, 2007
6. ^ Sternberg, R. J., & Grigorenko, E. L. (1999). Our labeled children: What every parent and teacher needs to know about learning
disabilities. Reading, MA: Perseus Publishing Group
7. ^ Center for Law and Social Policy, 1998
8. ^ |New York State Rehabilitation Association, 2007| http://www.nyrehab.org/Text/WED_Welfare.cfm
9. ^ http://www.nga.org/cda/files/072898LEARNING.pdf|Center for Law and Social Policy, 1998
10. ^ NGA Issue Brief
11. ^ NGA Issue Brief
12. ^ Moody et. al., 2007
13. ^ Read et. al., 1985, 1988
14. ^ Moody et. al., 2007
15. ^ Christianson, 2007
16. ^ Snow, et.all, 1999
17. ^ Office of Juvenile Justice and Delinquency Prevention, 1994, and U.S. Department of Justice, Bureau of Justice Statistics, 1995


* Aaron, P.G., (1995) Differential diagnosis of reading disabilities. School Psychology Review 24(3), 345-360.
* Flanagan, D.P., & Mascolo, J.T. (2005). Pyschoeducational Assessment and Learning Disability Diagnosis. In D.P. Flanagan & P.L.
Harrison (Eds). Contemporary Intellectual Assessment: Theories, Tests, and Issues. New York: The Guildford Press.
* Lyon, G. Reid; Jack M. Fletcher & Sally E. Shaywitz et al. (2001), "Rethinking Learning Disabilities", in Finn, Chester E.; Andrew
Rotherham & Charles R. Hokanson, Rethinking Special Education for a New Century, PPI and The Thomas B. Fordham Foundation,
* Moody, K.C. & C.E. III Holzer (June), "Prevalence of dyslexia among Texas prison inmates", Texas Medicine 96 (6): 69-75, <http://www.
ncsall.net/?id=525> (retrieved on 2007-06-19)
* [www.nga.org/cda/files/072898LEARNING.pdf "{{{title}}}"] in NGA Center for Best Practices, Employment and Social Services Policy
Studies Division. Retrieved on June 28, 2007.
* Moody, K.C. & C.E. III Holzer (June), "Prevalence of dyslexia among Texas prison inmates", Texas Medicine 96 (6): 69-75, <http://www.
ncsall.net/?id=525> (retrieved on 2007-06-19)
* Snow, Catherine E. & John Strucker (1999), "Lessons from Preventing Reading Difficulties in Young Children for Adult Learning",
National Center for the Study of Adult Learning and Literacy 1 (2), <http://www.ncsall.net/?id=525> (retrieved on 2007-06-19)
* The New York State Rehabilitation Association, in Welfare to Work and “Hidden” Disabilities (2007), http://www.nyrehab.
org/Text/WED_Welfare.cfm retrieved June 19, 2007.