Researchers find a link between resilience to dyslexia and gray matter in the brain

July 24, 2018

Dyslexia, a reading disorder, is characterized by difficulty in "decoding" – navigating between visual form and the sounds of a written language. But a subset of dyslexic people, dubbed "resilient dyslexics," have remarkably high levels of reading comprehension despite decoding difficulties. What is the precise mechanism that allows some people with dyslexia to overcome their low decoding abilities and extract meaning from the text?

A new joint study from Tel Aviv University and the University of California at San Francisco identifies the mechanism of the brain.

The research was conducted jointly by Dr. Smadar Patael from the Department of Communication Disorders at the TAU and Professor Fumiko Hoeft, currently at the University of California at San Francisco and who begins as director of the 39; University. of the Connecticut Brain Imaging Center this fall. The research was recently published in PLOS ONE .

Measurement of Gray Matter

Research indicates a greater volume of gray matter in resilient drives in the part of the brain responsible for executive functions and working memory. This specific region, the dorsolateral prefrontal cortex (DLPFC) of the left hemisphere, is known as the "air traffic controller" or "driver" of the brain. Gray matter is the darkest tissue in the brain and spinal cord, consisting mainly of nerve cells and branched dendrites.

The researchers examined 55 English-speaking children aged 10 to 16 with a wide range of reading skills. Half of these children had been diagnosed with dyslexia. The researchers created a simple formula for calculating the difference between reading skills and participant decoding skills. The participants were scanned with an MRI. The researchers then compared the participant's brain-mapping images with their reading skill scores.

"We wanted to determine whether areas of the brain related to language or other regions were responsible," says Dr. Patael. "We found that the region in the left frontal part of the brain known as the left DLPFC was directly related to this discrepancy. The DLPFC has been shown to be important for executive functions and cognitive controls."

"We then sought to understand the answer to a question of" hen or egg "related to dyslexia and the slight enlargement of this region of the brain", continues Dr. Patael. "Do resilient dyslexics have distinct brain structures that allow for better resilience, or their success in reading a result of compensatory strategies that have actually altered the density of neurons in a specific region of the brain?" [19659003] Patael, Professor Hoeft and colleagues scanned 43 kindergarten children using MRI technology, and three years later tested children's reading skills. The researchers found that the density of neurons in the DLPFC was earlier than the mature reading ability and predicted the discordance, regardless of their initial reading abilities

"This helps us understand the cognitive and brain mechanisms that these children use In spite of the relative weakness of their decoding, this could help us to integrate relatively new strategies in reading interventions, "says Professor Hoeft

" Much of the read-through program focuses on the learning of letters and phonological awareness. "concludes Dr. Patael. "Our research findings suggest new approaches that focus on executive functions and working memory. If your child enters first grade, the practice of the alphabet may not be enough. Think about the activities that require working memory, such as cakes and strategy games, activities stimulate the working memory of children and can, over time, improve their ability to fully understand the texts. "

Researchers are currently exploring the neural mechanisms of compensation and resilience