Different features of visual function mature along unique timescales through infancy and early childhood. It is not clear
which functions continue to mature in school age children. Functions believed to be mediated by the Magnocellular (M) and
Parvocellular (P) pathways were compared in five- (
n=25), eight- (
n=21) and eleven-year-old children (
n=21) and young adult controls (
n=20). Steady-state visual evoked potentials were recorded from occipital electrodes in response to very low spatial frequency
gratings, at a series of contrasts (M), and to high contrast gratings at a series of spatial frequencies (P). No evidence
was found to indicate M pathway development across these age groups. However, the youngest children demonstrated elevated
VEP thresholds to the high contrast gratings compared with either the adults or eleven-year-olds. This difference in threshold
implies an immaturity of the high contrast, high spatial frequency stream, i.e. the putative P pathway.
magnocellular pathway - parvocellular pathway - steady state VEP - visual development
This revised version was published online in July 2006 with corrections to the Cover Date.