|
Learning disabilities (LD) is a
term that refers to a varied group of disorders
that is manifested as significant difficulties in
the acquisition and use of listening, speaking,
reading, spelling, writing, reasoning, or
mathematical abilities. These disorders are
intrinsic to the individual and are presumed to be
due to central nervous system dysfunction. The
term does not include children who have learning
problems which are primarily the result of visual,
hearing, or motor handicaps, of mental
retardation, of emotional disturbance, or of
environmental, cultural, or economic disadvantage.
Children with LD have average or above average
intelligence. Currently the most accepted approach
to defining a learning disability is one in which
there is a significant discrepancy between a
child's potential for learning and his/her
achievement. Children with LD have difficulties
learning in the traditional way at the accepted
rate for their age group. For some reason their
channels for learning do not process stimuli in
the usual way. As a result, input and expression
can be affected. The Learning Disabilities
Association of Canada says 10% of Canadians have a
learning disability serious enough to require some
form of therapy. Learning disabilities affect boys
and girls equally, although more boys are referred
for help, perhaps because they are more disruptive
to parents and teachers.
Types & Manifestations
Learning problems can be divided
into two main groups:
- Involvement of
auditory-visual processes, resulting in reading
disorders (dyslexia) and other language-based
learning problems.
- Involvement of visual and
motor processes, resulting in poor handwriting (dysgraphia),
problems with mathematics (dyscalculia) and
deficits in social skills.
Dyslexia and Language-Based
Learning Disabilities
Dylexia is the most common of
the learning disabilities and the one that causes
most long-term problems. It is not caused by any
visual acuity problem but is actually due to
impaired language-processing skills. Dylexics have
a problem with decoding "phonemes", the individual
speech sounds in the alphabet, and have difficulty
with "phonics", the ability to sound out words.
One must be able to decode letters quickly and
automatically in order to concentrate on the
meaning of the words.
Dylexics also have a problem
with verbal short-term memory and therefore have
problems recalling letters, words, phrases, names,
dates, phone numbers, addresses, and other rote
facts. Besides having problems with understanding
written material, many children with auditory
processing problems have difficulty with
understanding what they hear. Distinguishing
similar sounds in words such as "dog" vs. "log"
may be an additional problem, especially in a
noisy environment. Following verbal directions at
home and in school may be confusing to some
children with LD.
One needs phonics to be able to
read and spell words properly, which is often a
problem for dylexics. Another problem for dylexics
is mathematics because they have difficulty
memorizing basic math facts and remembering
sequences of steps for computation. They often
reverse or mislabel numbers, e.g. 13 for 30, and
often have difficulty with understanding word
problems. Dyslexics often have a history of
delayed speech and mispronouncing words, because
certain sounds are omitted, substituted or
distorted.
Nonverbal Learning Disabilities
(NLD)
Problems with arithmetic and
handwriting, and deficits in social awareness and
social judgment are associated with NLD. These
comprise about 1% to 10% of learning disabilities.
The right side of the brain processes nonverbal
information and deals with spatial awareness,
recognition of visual patterns, and coordination
of visual information with motor processes
(visual-motor integration).
Children with NLD can have
psychomotor and tactile-perceptual deficits and
may be poorly coordinated in gross and fine motor
skills. As a result, they are delayed at tying
shoes, holding a pencil, catching a ball, riding a
bike, and assembling puzzles. They have
visual-perceptual-organizational deficits and have
problems with eye-hand coordination such as
difficulties with handwriting, drawing, and
copying from the blackboard.
The specific problem these
children have with mathematics is that they have
problems understanding fundamental concepts or
what approach is required to solve a problem. They
do, however, have strong psycholinguistic skills
such as rote verbal learning, word recognition and
spelling.
These children are often
described as being socially isolated, with few
close friends and limited social activity. They
have problems understanding jokes, strategies of
games, motives of others, and social conventions.
They often lack insight into their own future,
strengths and weaknesses. Possible reasons for
these social problems include poor social
comprehension, inability to take the perspective
of others, misinterpretation of body language,
impulsivity, and being easily led.
Coexisting Conditions
Attention-Deficit Hyperactivity
Disorder
ADHD occurs in 26%-41% of
children with learning disabilities. This
combination may be due to the fact that ADHD
children are inattentive and learn poorly, or
perhaps 'tune out'. Children with LD experience
frustration and may be unable to sustain attention
because the academic demands are too hard. Studies
suggest that ADHD and LD are not genetically
linked.
Psychological Disturbances
Depression and anxiety disorders
occur in one-third of learning-disabled (LD)
children, especially in those with nonverbal
learning disabilities. It is not surprising since
these children often have very low levels of
self-esteem, following years of experiencing
failure at school and being labeled "dumb" by
peers. Conduct disorder and ADHD occur in about
one third of LD children, especially in those with
language-based reading disabilities.
Causes
Heredity is a primary factor in
language-based learning disabilities. 35%-40% of
close relatives of dylexics have similar
difficulties. As with ADHD, there is a link
between learning disabilities and maternal abuse
of alcohol and cocaine during pregnancy. Dyslexia
is associated with left-brain dysfunction, the
side of the brain that is specialized for
language. Researchers have found that an area in
the left hemisphere, known as the planum
temporale, which is normally larger on the
left side than the right, is either the same size
or smaller in dyslexics. Nonverbal learning
disabilities have been found in children with
severe head injuries, hydrocephalus and radiation
treatment of the head. Since these conditions
involve destruction of white matter in the right
hemisphere, it is felt that nonverbal learning
disabilities are caused by early damage to white
matter in the right hemisphere.
Diagnosis
Early diagnosis is the central
focus of treatment. It is important that a
diagnosis be made before skill levels and
self-esteem slip to dangerous lows. The child's
physician should look for any neurologic
dysfunction and assess hearing, and vision to rule
out any sensory or neurological problem affecting
learning. He/she should take a history of
developmental milestones to rule out mental
retardation or autism, and inquire about behaviour
and attention span. Medications such as
antihistamines, anticonvulsants, tranquillizers,
and asthma medications may affect attention and
learning. Formal assessment, by a psychologist, of
intelligence and educational achievement is
occasionally necessary. Reports from teachers
and/or IQ tests can give information about
cognitive strengths and weaknesses and help define
how well the child processes information. Some of
the more frequently used intelligence tests for
school-aged children are the Wechsler Intelligence
Scale for Children (WISC-III) and the Stanford
Binet Intelligence Scale. Academic achievement can
be assessed by tests such as the Peabody
Individual Achievement Test-Revised (PIAT-R),
Woodcock-Johnson Tests of Achievement-Revised (WJ-R)
and the Wide Range Achievement Test-Revised (WRAT-R).
Treatment
Educational Therapy
The cornerstone of treatment of
learning disabilities is educational therapy. This
must be tailored to the individual needs, and
depends on the child's learning strengths and
weaknesses. There are many programs to teach
reading skills, including intensive phonetic
teaching programs. There is no evidence, however,
that any one reading technique is better than
another.
Besides remedial reading
techniques, some have tried teaching LD children
learning strategies . There has been some success
to instructing them to improve the way they
approach new tasks, memorize new information (e.g.
using mnemonics), and organize information (e.g.
using rhymes or visual images to link specific
bits of information together.) One successful
strategy is the "write-say" method which involves
the student rewrite incorrectly spelled words
several times while spelling the word out loud. A
variant of this method has also proved successful
in teaching multiplication tables.
Other methods to help LD
children include the use of other children in the
class or school acting as tutors, as well as
computer-assisted instruction methods. Children
with writing disorders, may be helped by using
classmate's notes, homework buddies, oral testing,
and being taught keyboarding.
Other Therapies
Social skills training,
psychological counseling, and behaviour management
techniques are often used therapies, but have not
been shown to be consistently helpful. In the
child with LD and ADHD, stimulant medications have
been shown to improve classroom performance, not
only through improved attentiveness, but also in
the way the central nervous system processes
information. In reading tasks, this effect is seen
in improved word-finding abilities.
Most Boards of Education are
required by law to provide specialized education
for LD children. This may mean special classes,
special teachers, or even a special school. There
is evidence, though, that teaching LD students in
regular classes, using highly motivated,
well-trained teachers, and teachers' aides, can
lead to improvements in academics, behaviour, and
self-esteem.
One of the most valuable
supports for parents is the Association for
Children with Learning Disabilities (ACLD). It
provides parents with information about local
services and new discoveries and offers support
groups in which parents can compare notes and
provide encouragement.
Prognosis
The outcome in children with LD
is better for those who are of higher
intelligence, have a less severe disability, are
in a higher socioeconomic class, attend private
school, are not hyperactive, and have no
neurologic findings. Most children with reading
disability can compensate and attain literacy, but
as adults they do less well in areas of work and
social and psychological adjustment. However, with
the right support systems, many people with LD can
achieve high academic and professional success,
e.g. Winston Churchill and Thomas Edison.
|
