August 14, 2013
Brain Scans Show Dyslexia In Pre-K Kids
Brett Smith for redOrbit.com - Your Universe Online
Dyslexia is typically diagnosed when a child is 7 or 8 years old, but new research from MIT could help identify kids at-risk for the reading disorder before they even begin to recognize words and their meanings.
Using advanced brain imaging technology, scientists at Boston Children’s Hospital have identified a connection between poor pre-reading skills in kindergartners and the size of a brain structure called the arcuate fasciculus, according to a report in the Journal of Neuroscience.
The new study builds on previous research which has shown that the arcuate fasciculus is smaller and more disorganized in adults with reading disabilities. MIT scientists said they were interested in finding out if the brain structure caused disabilities or was the result of a lack of reading experience.
“We were very interested in looking at children prior to reading instruction and whether you would see these kinds of differences,” said study co-author John Gabrieli, a professor of brain and cognitive sciences at MIT.
The latest study began as part of a larger research project involving about 1,000 children in kindergarten at schools in Massachusetts and Rhode Island. Children whose parents had given them permission to participate were tested on their pre-reading skills, such as being able to assemble words from sounds.
“From that, we’re able to provide — at the beginning of kindergarten — a snapshot of how that child’s pre-reading abilities look relative to others in their classroom or other peers, which is a real benefit to the child’s parents and teachers,” said study researcher Elizabeth Norton, a neuroscientist from MIT.
A set of 40 children was chosen from the larger group to have their brains imaged at MIT. The brain scans showed the size and organization of the brain’s information-carrying nerves, or white matter. As suspected, the images revealed a connection between the volume and organization of the arcuate fasciculus and the capacity to recognize and work with the sounds of language.
The neuroscientists also tested the kindergarteners on two other pre-reading skills: rapid naming, which is the ability to identify familiar objects as quickly as possible, and the ability to name letters. The researchers were unable to link performance on these tests to features of the arcuate fasciculus.
Gabrieli said structural differences found in the study could be the result of either genetic differences or environmental influences.
“At the moment when the children arrive at kindergarten, which is approximately when we scan them, we don’t know what factors lead to these brain differences,” he said.
The arcuate fasciculus is an important brain structure that connects two other essential structures – Broca’s area, which is used in speech production, and Wernicke’s area, which processes both written and spoken language. The study’s results support the idea that a large, organized arcuate fasciculus facilitates communication.
The researchers said they plan to track their participants and their reading skills throughout the coming year.
“We don’t know yet how it plays out over time, and that’s the big question: Can we, through a combination of behavioral and brain measures, get a lot more accurate at seeing who will become a dyslexic child, with the hope that that would motivate aggressive interventions that would help these children right from the start, instead of waiting for them to fail?” Gabrieli said.