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People who experience reading and/or writing difficulty without being
otherwise intellectually disabled are said to suffer from dyslexia.
Studying dyslexia is very valuable for understanding intelligence and
creativity. Dyslexia illustrates the power of inborn wiring of the brain in
developing mental skills.
At the same time it can show how inborn limitations can be overcome by using
the compensatory power of the brain.
Dyslexia is caused by an inability to handle linguistic information in
visual form. There is also a form of dyslexia that relates to the ability to
read standard analog clocks, which is a rotational positioning dyslexia, as
opposed to the symmetric dyslexia found with dyslexics that have reading and
5-15% of the population can be diagnosed as suffering from various degrees
Its main manifestation is a difficulty in developing reading skills in
elementary school children.
Those difficulties result from reduced ability to link up visual symbols
with sounds. In the past, dyslexia was mistakenly thought to have a
Researchers studying the brains of dyslexics have, however, found that in
reading tasks dyslexics show reduced activity in the left inferior parietal
Otherwise, dyslexics are known to often show higher than average
intelligence. A number of bright brains are said to have suffered from
varying degree of dyslexia. Those include Albert Einstein, Thomas Edison,
Alexander Graham Bell, Michael Faraday, and many others.
Dyslexics may show a natural dislike of reading and, in consequence,
compensate by developing unique verbal communication skills, inter-personal
and leadership skills.
Hence so many prominent CEOs list minor to severe dyslexia among their
Those include Richard Branson (Virgin Enterprises), Henry Ford, Ted Turner
(AOL Time Warner), John Chambers (Cisco), as well as prominent statesmen:
Winston Churchill, George Washington, Thomas Jefferson, John F. Kennedy and others.
Perhaps for similar reasons, many dyslexics tend to take on arts (e.g. Tom
Cruise or Whoopi Goldberg).
The list above indicates that those who show reading difficulties in
childhood can also cope well with their deficiency later in life and become
avid readers and skilled writers. Research shows that intense training in
dyslexics helps them use the right part of their brain to take over the
limited functionality in the left part.
Even a few weeks of intense phonological training (e.g. breaking down and
rearranging sounds to produce different words) can help noticeably improve
reading skills. Unlike in normal adults, phonological training shows an
increase in the activity in the right temporoparietal cortex.
This part of the brain works in spatial tasks and may be the main
compensatory structure in phonological training. This is the sister region
of the left temporoparietal cortex responsible for visual motion processing
which is underactive in many dyslexics. The earlier the phonological regimen
is taken on, the better the overall result. Advanced brain scans could
identify children at risk of dyslexia before they can even read.
In 1979, anatomical differences in the brain of a young dyslexic were
documented. Albert Galaburda of Harvard Medical School noticed that language
centers in dyslexic brains showed microscopic flaws known as ectopias and
microgyria. Both affect the normal six-layer structure of the cortex. An
ectopia is a collection of neurons that have pushed up from lower cortical
layers into the outermost one. A microgyrus is an area of cortex that
includes only four layers instead of six.
These flaws affect connectivity and functionality of the cortex in critical
areas related to sound and visual processing. These and similar structural
abnormalities may be the basis of the inevitable and hard to overcome
difficulty in reading.
Several genetic regions on chromosomes 1 and 6 have been found that might be
linked to dyslexia. In all likelihood, dyslexia is a conglomeration of
disorders that all affect similar and associated areas of the cortex. With
time, science is likely to identify and classify all individual suborders
with benefits to our understanding of how low-level genetic flaws can affect
the wiring of the brain and enhance or reduce a particular component of
human mental capacity.
Some studies have concluded that speakers of languages whose orthography has
a strong correspondence between letter and sound (e.g. Korean and Italian)
have a much lower incidence of dyslexia than speakers of languages where the
letter is less closely linked to the sound (e.g. English and French).
Whether today's models of dyslexia are correct or not, the main lesson of
dyslexia is that minor genetic changes affecting the layering of the cortex
in a minor area of the brain may impose inborn limitation on the overall
intellectual function. At the same time, dyslexia shows that the brain
exhibits a strong ability to compensate for its inborn or acquired
limitations, and intense training can often result in miraculous turnabouts
In English law, the failure of schools to diagnose and provide remedial help
for dyslexia became grounds for personal injury litigation in 1999 following
a House of Lords decision in the case of Pamela Phelps.
The British Disability Discrimination Act also covers dyslexia.
"In some cases, people have 'coping strategies' which cease to work in
certain circumstances (for example, where someone who stutters or has
dyslexia is placed under stress). If it is possible that a person's
ability to manage the effects of the impairment will break down so that
these effects will sometimes occur, this possibility must be taken into
account when assessing the effects of the impairment."
[Paragraph A8, Guidance to the Definitions of Disability]