Speech impairment is an extremely common disorder, affecting about two children in every grade. Children with developmental speech impairment have difficulty understanding and using their native language, having difficulty with grammar, vocabulary and conversation.
In the study, which was published in the journal eLife, Dr. Saloni Krishnan and her colleagues used MRI brain scans that were particularly sensitive to different properties of brain tissue. For example, the scans measured the amount of myelin and iron in the brain. Myelin is a fatty substance that envelopes neurons and speeds up the transmission of signals between parts of the brain. It is similar to the insulation around electrical wires.
The study found that children with language impairment have less myelin in areas of the brain responsible for learning rules and habits, as well as producing and understanding language.
This type of scan tells more about the structure or composition of brain tissue in different areas, according to the study's authors. The findings may help understand the pathways involved at the biological level and ultimately help explain why children with language developmental disabilities have trouble learning language.