Researchers are developing new diagnostic methods that should make it easier to identify dyslexia in young children. One method involves the use of scans to show how parts of the brain respond to certain tasks.
Three researchers presented details of their work with dyslexic individuals. The disorder, which affects between 5 and 15 per cent of the population, "is itself a high risk for depression and suicide", said Dr Frank Wood of the Wake Forest University School of Medicine.
Dr Wood has been searching for genes thought to be associated with dyslexia. A number of candidate genes have been located on several different chromosomes and, if confirmed, tests for them could provide a way to confirm the disorder, even in very young children who have not yet shown symptoms.
The use of brain scans is helping researchers to assess how effective various reading "intervention programmes" are, said Dr Guinevere Eden of the Georgetown University Medical Center.
Adults with long-diagnosed dyslexia undertook an eight week period of study involving 3-1/2 hours of training each day. Brain scans were taken before and after the training.
"What we found was the intervention did improve their reading," but it had an unexpected effect on brain function. The left half of the brain is associated with reading ability but there was no change to this half of the brain, she said.
There was, however, a change to the corresponding part of the right side of the brain which implied the brain was "plastic" enough to compensate to a degree.
Dr Thomas Zeffiro, also of Georgetown University Medical Center, described how dyslexia could have an impact not just on reading and language but also on certain motor skills and sensory responses.
These impacts were very subtle and generally not noticed by those with the disorder, he said. Careful laboratory tests could identify them, however.