By: Inas Essa

Children with dyslexia—a common learning difficulty that can cause problems with reading, spelling, and writing—have been thought to have reduced sensitivity to visual information, which leads to struggling with reading. Although the link between reduced reading ability and dyslexia has been well known, researchers have been unclear on which brain processes are affected by the condition. Increasing the understanding of this problem could lead to more effective support for those children.

New research has shed light on which brain processes are affected by dyslexia beyond just reading ability; it has found how visual processing speed is reduced in children with dyslexia. The study, published in the Journal of Neuroscience, suggests that dyslexic children have difficulty with reading because they are slower to process visual information.

Monitoring Visual Motion Processing

Through the study, researchers challenged a group of children, 50 children with dyslexia and 50 typically developing children aged 6 to 14 years, to identify the average direction of motion of a mass of moving dots as accurately and quickly as possible, while their brain activity was measured. Based on this study, the researchers aimed to investigate which processing stages are affected in children with dyslexia when performing visual motion processing tasks.

Results showed that dyslexic children took much longer to gather the visual evidence, and were less accurate, than the typically developing participants, and that the behavioral differences were reflected in differences in brain activity. Moreover, the study supports a link between motion processing and dyslexia, although the causes are not yet known.

Brain activity monitoring during the study indicated that a synchronized activity over certain regions of the brain that are involved in decision-making was steadily increased in all of the children during the task until they made a decision. However, with dyslexic children, this happened more gradually. “These findings show that the difficulties faced by children with dyslexia are not restricted to reading and writing. Instead, as a group, children with dyslexia also show differences in how they process visual information and make decisions about it,” said Dr. Cathy Manning, the lead researcher in the Centre for Autism at the University of Reading.

Dr. Manning added: “Future research will be needed to see if these differences in visual processing and decision-making can be trained to improve reading ability in affected children, or provide clues as to the causes of dyslexia”.

References

jneurosci.org

neurosciencenews.com