Summary: The first two years of primary education are a critical point for the development of the brain’s reading network in children, researchers say.
Source: KU Leuven
The regions that form the reading network in the brain mainly develop in the first two years of primary school. After that, the growth of these brain regions stabilises. This has been shown by a year-long study conducted by KU Leuven in collaboration with technology company icometrix.
The results highlight the importance of early intervention with reading problems such as dyslexia. This often begins in the third year at present, but the brain is less amenable to development at that time.
The study involved 75 children from Flanders, who were monitored for several years. Each year, they were given several reading and language-related tests, and had an MRI scan at three points: at the end of kindergarten (preschool education in Flandres, for children ranging from 2.5 to 6 years), after the second year of primary school, and halfway through the fifth year of primary school. This enabled the researchers to observe how the brain develops during different reading phases and the extent to which this differs in children with dyslexia.
“This allowed us to establish that the neurobiological differences between children with and without dyslexia are already present before they learn to read,” says Professor Maaike Vandermosten (Department of Neuroscience), lead author of the study. “In children with dyslexia, we see less volume of the brain in the lower left region at the back. The connection between this region and regions at the front is also less well-developed.”
“In the further development of the reading regions on the left-hand side of the brain, we did not observe any structural differences between children with or without dyslexia. Development is therefore similar, but the differences that were already present at pre-school age are no longer being compensated for.
“In addition, we found that children with dyslexia show different development in the brain regions on the right-hand side, beyond the reading network. This could be interpreted as compensation for the reading problems these children experience, but that strategy doesn’t seem to be very efficient.”
About this reading and neurodevelopment research news
Author: Press Office Source: KU Leuven Contact: Press Office – KU Leuven Image: The image is in the public domain
Structural brain dynamics across reading development: A longitudinal MRI study from kindergarten to grade 5
Primary education is the incubator for learning academic skills that help children to become a literate, communicative, and independent person.
Over this learning period, nonlinear and regional changes in the brain occur, but how these changes relate to academic performance, such as reading ability, is still unclear.
In the current study, we analyzed longitudinal T1 MRI data of 41 children in order to investigate typical cortical development during the early reading stage (end of kindergarten–end of grade 2) and advanced reading stage (end of grade 2–middle of grade 5), and to detect putative deviant trajectories in children with dyslexia.
The structural brain change was quantified with a reliable measure that directly calculates the local morphological differences between brain images of two time points, while considering the global head growth.
When applying this measure to investigate typical cortical development, we observed that left temporal and temporoparietal regions belonging to the reading network exhibited an increase during the early reading stage and stabilized during the advanced reading stage. This suggests that the natural plasticity window for reading is within the first years of primary school, hence earlier than the typical period for reading intervention.
Concerning neurotrajectories in children with dyslexia compared to typical readers, we observed no differences in gray matter development of the left reading network, but we found different neurotrajectories in right IFG opercularis (during the early reading stage) and in right isthmus cingulate (during the advanced reading stage), which could reflect compensatory neural mechanisms.