JPost-Reading and white matter in the brain
A new study that focuses on “white matter” finds that learning how to read relies on changes in brain connections.
Photo by: Wikicommons
Learning to read relies on changes in brain connections, according to a newly published study in PNAS, Proceedings of the [US] National Academy of Science. Dr. Michal Ben- Shachar of Bar-Ilan University’s English department and the Gonda (Goldschmied) Multidisciplinary Brain Research Center, is part of a research team that conducted the “unique” study.
Ben-Shachar’s studies focus on “white matter” – a network of pale, myelin-sheathed connections that allows information transfer between distant parts of the brain. She and her fellow researchers use diffusion tensor imaging (DTI) and an MRIbased, non-invasive technique to measure the properties of the white-matter connections and how they change over time. Using DTI the team, led by Stanford University Prof. Brian Wandell, tracked the development of reading skills and white matter connections in 55 children ages seven to 12 over a three-year period and related changes in the brain to changes in reading skill.
“The nice thing about DTI is that it is really child friendly. In a 12-minute scan, you can collect high-quality data from the whole brain, while the child is lying still watching a movie.
At Stanford, we scan children as young as six, and they do this very well,” says Ben-Shachar, who conducted her post-doctoral research at Stanford and continues from Israel to collaborate with two labs there.
The researchers found that high-performing readers initially had lower levels of white matter in the areas of the brain associated with reading, but these levels grew rapidly during the three years studied. By contrast, below-average readers had higher initial levels of white matter in the areas associated with reading, but these levels declined over time, suggesting the children were not creating and strengthening neural pathways.
“This study is unique in its longitudinal aspect. Most developmental imaging studies compare brain measures in groups of children and adults. In contrast, we followed up on the same group of children over a long period of time. By doing so, we discovered that the changes in brain connections are more informative about reading skill than the measurement at a specific point in time,” says the Bar-Ilan researcher.
“This is really important if we are ever going to use MRI as a diagnostic tool in education, in addition to standard behavioral tools. It means we will have to assess the child more than once in order to look at dynamic developmental changes, because change is more important than absolute measures at a particular time point,” she concludes.
In a project awarded a prestigious grant from the Israel Science Foundation, she and Tel Aviv University colleagues Ofer Amir and Ruth Ezrati are looking at white matter pathways in the brains of people who stutter. Separately, she is working with Ethiopian immigrants, for some of whom Hebrew is their first written language, in the hope of identifying how the adult brain changes as literacy is acquired.
