Where were those rabbits? A new paradigm to determine cerebral lateralisation of visuospatial memory function in children.

In the majority of people, functional differences are observed between the two cerebral hemispheres: language production is typically subserved by the left hemisphere and visuospatial skills by the right hemisphere. The development of this division of labour is not well understood and lateralisation of visuospatial function has received little attention in children. In this study we devised a child-friendly version of a paradigm to assess lateralisation of visuospatial memory using functional transcranial Doppler ultrasound (fTCD). In a group of 24 adults we found this child-friendly version gave similar results to the original version of the task. In addition, fourteen children aged 6-8 years successfully completed the child-friendly fTCD task, showing a negative lateralisation index, indicating right hemispheric specialisation at the group level. Additionally, we assessed effects of task accuracy and reaction time on the lateralisation index. No effects were found, at the group level or at the level of single trials, in either the adult or the child group. We conclude that this new task reliably assesses lateralisation of visuospatial memory function in children as young as 6 years of age, using fTCD. As such, it holds promise for investigating development of lateralisation of visuospatial function in typically and atypically developing children.