Developmental language disorder (DLD) is common, yet the neurobiology of DLD is poorly understood. A key hypothesis suggests atypical functional lateralization of language, which might be accompanied structurally by a deficit in inter-hemispheric connectivity of language-related regions. Indeed, aberrations of the corpus callosum have been associated with language deficits in children with frank neurological lesions and/or born pre-term. In contrast, studies examining the corpus callosum in children with DLD remain elusive.

We aimed to expand this largely understudied field by comparing callosal morphology between 17 children with DLD and 17 typically developing children carefully matched for sex and age.

We analyzed high-resolution structural magnetic resonance imaging data applying a well-validated computational approach, which captures the thickness of the corpus callosum with a high regional specificity at 100 equidistant points.

As shown in Fig. 1, we observed a significantly thinner corpus callosum, particularly in the splenium, in children with DLD compared to typically developing controls (DLD<CTL).

These findings indicating pronounced aberrations in the brain's largest whiter matter tract make an important contribution to an understudied field of research and support the theory that DLD is accompanied by atypical lateralization of language function.