Brain white matter strongly predicts reading acquisition beyond genetic risk
Researchers at the University of California, San Francisco (UCSF) have shown that patterns of white matter development in young children’s brains can forecast how well they will learn to read. By combining brain imaging with standard early assessments, the team identified neural markers that predict reading outcomes beyond family history, cognitive measures, and socioeconomic factors. These findings point to a potential clinical tool for earlier detection of reading difficulties, including dyslexia, before children begin to struggle in school.
In the United States, children typically receive formal reading instruction beginning in kindergarten and are expected to become fluent readers by about third grade. To better understand neural contributions to this learning process, UCSF investigators scanned the brains of 38 children during kindergarten—the period when they first learn formal reading—and followed those same children through third grade, measuring changes in white matter over time. White matter, composed of the nerve fibers that connect different brain regions, plays a crucial role in perception, language processing, and learning.
The team’s analyses showed that trajectories of white matter development in specific left hemisphere regions were strongly associated with later reading ability. In particular, changes in white matter around the temporo-parietal region—an area just behind and above the left ear that is known to support language, phonological processing, and decoding—predicted how well children learned to read, even after accounting for commonly used early measures.
“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,” said Fumiko Hoeft, MD, PhD, senior author of the study and associate professor of child and adolescent psychiatry at UCSF. Hoeft is also a member of the UCSF Dyslexia Center.
Traditional early assessments of reading readiness typically include behavioral measures such as letter knowledge and phonological awareness, as well as cognitive tests (for example, general IQ), early language skills, family history of reading problems, and measures of the child’s environment such as socioeconomic status. To isolate the unique predictive power of brain development, the researchers statistically controlled for these factors. Even after removing the influences of genetics, cognitive ability, and environmental indicators present at the start of kindergarten, white matter development in the left temporo-parietal region remained a significant predictor of later reading success.
Importantly, incorporating longitudinal brain-imaging data markedly improved prediction. The authors report that brain scans enhanced the ability to predict which children would go on to experience reading difficulties by roughly 60 percent compared with traditional assessments alone. This improvement suggests that neural measures may capture developmental risk that behavioral tests miss, particularly during the earliest phases of reading instruction.
“Early identification and interventions are extremely important in children with dyslexia as well as most neurodevelopmental disorders,” Hoeft added. “Accumulation of research evidence such as ours may one day help us identify kids who might be at risk for dyslexia, rather than waiting for children to become poor readers and experience failure.”
Chelsea Myers, BS, the study’s lead author and lab manager in UCSF’s Laboratory for Educational NeuroScience, emphasized the value of tracking developmental change. “Examining developmental changes in the brain over a critical period of reading appears to be a uniquely sensitive measure of variation and may add insight to our understanding of reading development in ways that brain data from one time point, and behavioral and environmental measures, cannot,” Myers said. “The hope is that understanding each child’s neurocognitive profile will help educators provide targeted and personalized instruction and intervention, particularly for children with special needs.”
Reading difficulty is common: according to the National Institute of Child Health and Human Development, as many as 15 percent of Americans struggle significantly with reading. Earlier and more accurate identification of children at risk could allow timely, evidence-based interventions that improve long-term academic outcomes and reduce the negative effects of reading failure.
Co-authors on the study include Maaike Vandermosten, PhD; Emily Farris, PhD; Roeland Hancock, PhD; Paul Gimenez, BA; Brandi Casto, MS; Miroslav Drahos, MS; Mandeep Tumber, MS; Robert Hendren, DO; Jessica Black, PhD; and Charles Hulme, DPhil. The research was published in the journal Psychological Science and reports on the article titled “White Matter Morphometric Changes Uniquely Predict Children’s Reading Acquisition.”
The study received funding support from multiple sources, including the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the Flora Family Foundation, UCSF Catalyst Award, UCSF Resource Allocation Program, Brain & Behavior Research Foundation Young Investigator Award, Stanford University Lucile Packard Foundation for Children’s Health, Spectrum Child Health & Clinical and Translational Science Award, and the Dyslexia Foundation’s Extraordinary Brain Series.
Contact: Juliana Bunim – UCSF
Source: UCSF press release
Original research: Psychological Science, study by Chelsea A. Myers, Maaike Vandermosten, Emily A. Farris, Roeland Hancock, Paul Gimenez, Jessica M. Black, Brandi Casto, Miroslav Drahos, Mandeep Tumber, Robert L. Hendren, Charles Hulme, and Fumiko Hoeft. Published online September 11, 2014.