Weaker semantic language lateralization associated with better semantic language performance in healthy right-handed...

The relationship between language abilities and language lateralization in the developing brain is important for our understanding of the neural architecture of language development.

We investigated 35 right-handed children and adolescents aged 7-16 years with a functional magnetic resonance imaging language paradigm and a comprehensive language and verbal memory examination.

We found that less lateralized language was significantly correlated with better language performance across areas of the brain and across different language tasks. Less lateralized language in the overall brain was associated with better in-scanner task accuracy on a semantic language decision task and out-of-scanner vocabulary and verbal fluency. Specifically, less lateralized frontal lobe language dominance was associated with better in-scanner task accuracy and out-of-scanner verbal fluency. Furthermore, less lateralized parietal language was associated with better out-of-scanner verbal memory across learning, short- and long-delay trials. In contrast, we did not find any relationship between temporal lobe language laterality and verbal performance.

This study suggests that semantic language performance is better with some involvement of the nondominant hemisphere.