Sixth-grader Josh Thibeau has been struggling to read for as long as he can remember. He has yet to complete a single Harry Potter book, his personal goal.
Growing up with dyslexia: Josh Thibeau, 12, thinks of his brain as an ever-changing maze with turns he must learn to navigate. Here he is with his mom, Janet. (George Hicks/WBUR)
When he was in first grade, Josh’s parents enrolled him in a research study at Boston Children’s Hospital investigating the genetics of dyslexia. Since then, Josh has completed regular MRI scans of his brain. Initially, it seemed daunting.
“When we first started, I’m like, ‘Oh no, you’re sending me to like some strange, like, science lab where I’m going to be injected with needles and it’s going to hurt,’ I’m like, ‘I’m never going to see my family again,’ ” says Josh, who lives in West Newbury, Mass.
Josh and his three biological siblings all have dyslexia to varying degrees. Pretty much every day he confronts the reality that his brain works differently than his peers’. He’s even shared scans of his brain with classmates to try to show those differences. Some kids still don’t get it.
“There was a student that said, ‘Are you stupid?’ Because my brain was working in a different way,” Josh says. “And I’m just like, ‘No, I am not stupid…I’m just dyslexic.’ ”
The Pre-Reading Brain
On average, one or two kids in every U.S. classroom has dyslexia, a brain-based learning disability that often runs in families and makes reading difficult, sometimes painfully so.
Compared to other neurodevelopmental disorders like ADHD or autism, research into dyslexia has advanced further, experts say. That’s partly because dyslexia presents itself around a specific behavior: reading — which, as they say, is fundamental.
Now, new research shows it’s possible to pick up some of the signs of dyslexia in the brain even before kids learn to read. And this earlier identification may start to substantially influence how parents, educators and clinicians tackle the disorder.
Until recently (and sometimes even today) kids who struggled to read were thought to lack motivation or smarts. Now it’s clear that’s not true: Dyslexia stems from physiological differences in the brain circuitry. Those differences can make it harder, and less efficient, for children to process the tiny components of language, called phonemes.
And it’s much more complicated than just flipping your “b’s and “d’s.” To read, children need to learn to map the sounds of spoken language — the “KUH”, the “AH”, the “TUH” — to their corresponding letters. And then they must grasp how those letter symbols, the “C” “A” and “T”, create words with meaning. Kids with dyslexia have far more trouble mastering these steps automatically.
For these children, the path toward reading is often marked by struggle, anxiety and feelings of inadequacy. In general, a diagnosis of dyslexia usually means that a child has experienced multiple failures at school.
But collaborations currently underway between neuroscientists at MIT and Children’s Hospital may mark a fundamental shift in addressing dyslexia, and might someday eliminate the anguish of repeated failure. In preliminary findings, researchers report that brain measures taken in kindergartners — even before the kids can read — can “significantly” improve predictions of how well, or poorly, the children can master reading later on.
Implicated in dyslexia: The arcuate fasciculus is an arch-shaped bundle of fibers that connects the frontal language areas of the brain to the areas in the temporal lobe that are important for language (left). Researchers found that kindergarten children with strong pre-reading scores have a bigger, more robust and well-organized arcuate fasciculus (bottom right) while children with very low scores have a small and not particularly well-organized arcuate fasciculus (top right). (Zeynep Saygin/MIT)
Pinpointing The White Matter Culprit
Using cutting-edge MRI technology, the researchers are able to pinpoint a specific neural pathway, a white matter tract in the brain’s left hemisphere that appears to be related to dyslexia: It’s called the arcuate fasciculus.
“Maybe the most surprising aspect of the research so far is how clear a signal we see in the brains of children who are likely to go on to be poor readers.”
– MIT neuroscientist John Gabrieli
“It’s an arch-shaped bundle of fibers that connects the frontal language areas of the brain to the areas in the temporal lobe that are important for language,” Elizabeth Norton, a neuroscientist at MIT’s McGovern Institute of Brain Research, explains.
In her lab, Norton shows me brain images from the NIH-funded kindergartner study, called READ (for Researching Early Attributes of Dyslexia).
“We see that in children who in kindergarten already have strong pre-reading scores, their arcuate fasciculus is both bigger and more well organized,” she says. On the other hand: “A child with a score of zero has a very small and not particularly organized arcuate fasciculus.”
She says we’re not quite ready to simply take a picture of your child’s brain and say “Aha, this kid is going to have dyslexia,” but we’re getting closer to that point. Continue reading