Brain microstructural correlates of visuospatial choice reaction time in children

► Corticospinal tracts (CSTs) and neostriatum continue to develop during childhood. ► Diffusion MRI was used to study corticospinal tract and neostriatum microstructure. ► A simple visuomotor task assessed choice reaction time in children aged 7 to 13 years. ► Faster reaction times correlated with lower CST and neostriatum mean diffusivity. ► Children of similar age may vary in the phase of maturation of the motor system.