Dyslexia: Disorder That Might Have Its Good Points
Many architects, graphic artists and mathematicians tend to be afflicted with dyslexia, a learning impairment that apparently endows some people with exceptional abilities, a growing body of evidence suggests.
“A great many dyslexics have uncanny spatial skills,” said psychobiologist Mary-Louise Kean of the Center for the Neurobiology of Learning and Memory at the University of California, Irvine.
Spatial skills refer to ability to understand abstract ideas and concepts.
Albert Einstein, Thomas Edison and Michelangelo are believed to have been dyslexic, and their superior talents may have been linked to the reading disorder because of differences in brain development, Kean said.
Kean said dyslexic children have superior abilities in performing “map tasks.”
“They’ll get you to exactly where you want to go,” she said of an ability to equate positions on maps to actual distances that can permit arrival by the most direct route.
Kean said map reading and drawing skills carry into adulthood and probably are related to exceptional abilities in geometry and other mathematics.
“Most people think of dyslexia as a reading disorder, and it usually is diagnosed when a child fails to learn to read in the normal time course.
“But it is much more complicated than just a reading disorder and may very well have a genetic component,” she said.
Studies under way at the UC Irvine center show that in addition to spatial skills, many dyslexics also have superior vision and that dyslexia is diagnosed more often in boys than girls.
A Harvard University study suggests that specific hormones may be associated with dyslexia--particularly the male hormone testosterone--which may cause excessive development of the brain’s right hemisphere during the fetal stage.
Animal studies have shown that testosterone can enhance right brain development, a possible reason why more males than females tend to be dyslexic.
Kean and a team of researchers are now studying the infants and children of dyslexics to better understand how the disorder develops.
She said that dyslexia tends to occur with other genetically linked traits, that many dyslexics are left-handed and experience a high degree of allergies.
“Critical to a diagnosis of dyslexia, a child has to be of normal intelligence and have no psychological problems or neurological disease,” Kean said.
Ruling out such impairments permits psychologists and educators to design special reading programs aimed at helping dyslexic children understand how letters combine to form words.
The disorder, which was first identified in 1887 as “word blindness,” is characterized by an inability to process verbal information in the brain. A dyslexic will usually see the word “saw” for “was” and the letter “d” for “b.”
“We know that dyslexics are different beyond just an inability to read,” Kean said. “From a biological standpoint dyslexia can be seen as good because it gives diversity to society--dyslexia is not an issue in a society where reading is not important.
“We now recognize that dyslexics do not suffer from intellectual deficits and that many have very high IQs,” she explained.
In spite of their talents, Kean said scientists and educators cannot overlook the way dyslexic people process verbal information.
“They vary in memory capacities so it depends on the domain in which they are being tested.
“Dyslexics tend to do quite well when recalling or working out spatial problems, but when asked to recall verbal information, they usually do not perform well in these kinds of tasks,” she said.
In a comparison of dyslexics and non-dyslexics at the UC Irvine learning center, Kean said both groups were tested on how they processed verbal information by the way they responded to sentences.
“We asked both groups to make a value judgment of two sentences to see if they were good or bad,” she said.
The groups were told that “John promised Mary to mow the lawn and he did,” a sentence that both groups agreed was a “good” sentence and both agreed that “John mowed the lawn,” Kean said.
The second sentence stated that “John promised Bill to mow the lawn and he did,” a sentence that drew sharply different responses from dyslexics and non-dyslexics.
“Normal speakers say John mowed the lawn in the second sentence,” Kean explained. “But the dyslexic group said you can’t tell and say either John or Bill could have done it.”