Abstract
The visual system of human children is functionally immature at birth. Visual experience plays a key role in the maturation of human vision, as evidenced by the onset of amblyopia (“lazy eye”) in individuals with abnormal early visual experience. Since amblyopia can be successfully treated with occlusion therapy as late as ages 9–10, it might be expected that even normally-sighted children at these ages may exhibit cortical retinotopic organization which is different from that of adults. This study mapped the retinotopic organization of the first eight visual areas in alert, non-sedated children ages 7–12 using the fMRI BOLD technique at 1.5 T and standard phase-encoded methods. The high-contrast, temporally modulated stimuli separately map polar angle and eccentricity in visual cortex, and are identical to those used with adults (Sereno et al., 1995). We obtained distinct and reproducible retinotopic maps in children which are qualitatively similar to retinotopic maps obtained in adults under the same conditions. We conclude that retinotopic mapping using non-invasive fMRI is feasible for motivated children in this age range. We anticipate that retinotopic mapping can be used as a basis for region-of-interest analyses of differences in early visual areas in children with visual pathologies like amblyopia.
Supported by NIH/NCRR to JM