MRI Shows Brain Changes in Children with Difficulty Reading

Magnetic resonance images showed increases in the volume of white matter in children who had difficulties learning how to read, according to a study published in the journal, Psychological Science.

Researchers from the University of California, San Francisco, undertook a study to examine if there were developmental structural changes in neural circuits that could predict variations in reading outcomes in grade 3.

The study group comprised 38 children; 24 males and 14 females. All were healthy, native-English speakers. The subjects all underwent diffusion MR imaging, and completed standardized neuropsychological, reading, and cognitive assessments at age five or six, and again three school years later. Their home literacy levels were assessed as well.

When reading the images, the researchers saw that left hemisphere white matter in the temporo-parietal region was highly predictive of reading acquisition beyond effects of genetic predisposition, cognitive abilities, and environment at the outset of kindergarten. “The left arcuate fasciculus and superior corona radiata as key fibers within the two clusters,” the authors wrote. “Bias-free regression analyses using regions of interest from prior literature revealed that volume changes in temporo-parietal white matter, together with preliteracy measures, predicted 56% of the variance in reading outcomes.”

"We show that white matter development during a critical period in a child's life, when they start school and learn to read for the very first time, predicts how well the child ends up reading," senior author Fumiko Hoeft, MD, PhD, associate professor of child and adolescent psychiatry at UCSF and member of the UCSF Dyslexia Center, said in a release.

The researchers concluded that the development of differences in areas of left dorsal white matter, often implicated in phonological processing, is a sensitive early biomarker for later reading abilities, and by extension, reading difficulties.