Patterns of language and visuospatial lateralisation in three-year-old children

Little is known about how or when language and visuospatial processing lateralise in the brain, and if individual differences in lateralisation are related to early language or visuospatial abilities. We explored if patterns of language and visuospatial lateralisation are related to cognitive skills in young children. A large sample of 3-year-olds (n = 136) attempted two functional transcranial Doppler ultrasound (fTCD) tasks to estimate language and visuospatial lateralisation. At the group level, language was lateralised to the left hemisphere, but visuospatial processing was weakly lateralised to the right hemisphere. The relationship between patterns of lateralisation and cognitive skills was investigated using regression analyses with novel calculations of how typical a child's lateralisation pattern was, the degree of crowding of both functions to one hemisphere, or how strongly both functions were lateralised. Language and visuospatial abilities were not predicted by any of these measures. Degree of visuospatial lateralisation, and not language lateralisation, was associated with higher language ability. Future research should investigate if patterns of lateralisation are related to cognitive skills in older children, when lateralisation is more established.