New Study Exploring Brain Plasticity in Developmental Dyslexia

A recent study published in npj Science of Learning investigated and revealed new data on brain plasticity in developmental dyslexia through implicit sequence learning. Developmental dyslexia is a neurobiological disorder in which a person experiences difficulty in understanding and decoding written words, despite the absence of intellectual disability and with sufficient educational support. Despite its neurobiological origin, the brain structure of individuals with developmental dyslexia remains a big mystery.

Developmental dyslexia has an estimated prevalence of 5-15% across the globe with significant variability stemming from sociocultural factors, linguistic differences and differences in assessment methods. This study investigated potential variations in brain plasticity related to learning in children with developmental dyslexia by analyzing alterations in white and grey matter volume associated with sequential learning.

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The serial reaction task was designed as a multifaceted and complex assessment to evaluate different cognitive abilities such as motor skills based on sequences, perception, and cognitive functioning. The tasks included sequence-based trials that were integrated with visual and motor responses including fine movement encompassing general visuomotor learning skills. The current study aimed to induce change in grey and white matter volume through motor skills learning. 

The participants included 17 children with developmental dyslexia and 18 typically developing children to examine differences in brain plasticity. The study was performed over two days with a 24-hour interval to increase the validity of the data. Both groups were part of a large behavioural study focusing on memory and learning in children with reading problems. Data on implicit learning was collected through fMRI scans and was analysed to derive results. This study was conducted over two days and the data collected on both days were compared and analysed to determine brain plasticity. 

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The study revealed that grey matter volume in the right cerebellar increased in both typically developing children and children suggesting that it can grow over time. On the other hand, white volume matter showed significantly lower levels on day 2 compared to day 1. The tea discovered larger white matter volume in the left posterior thalamic radiation in children with developmental dyslexia compared to typically developing children.

It was concluded that brain plasticity can be influenced by implicit sequence learning in children with developmental dyslexia. The results revealed that children with developmental dyslexia use different underlying learning mechanisms as compared to typically developed children for solving implicit structured learning tasks. The results strengthened previous evidence that shed light on the atypical brain development in children with dyslexia. The team of researchers recommended teaching children with developmental dyslexia through more explicit stimulus-driven strategies to cope with and compensate for the reduced ability for implicit learning.