Absence of subcortical pathway optokinetic eye movements in an infant with cortical blindness

Tracking of large visual targets by normal neonates and by infants with visual cortex damage has led to the suggestion that infants use subcortical vision to guide visuomotor behaviors. To test this assertion, the author recorded eye movements in a five-month-old infant who became cortically-blind following an anoxic episode. Use of a full-field, high-contrast visual stimulus failed to elicit any evidence of optokinetic nystagmus. The findings in this infant lead to the conclusion that retinotectal visual inputs are incapable of driving eye movements in the young human in the absence of cortical vision.