Optokinetic technique for measuring infants' responses to color.

Two motion tests will measure normal and defective responses to color in non-verbal infants. Moving gratings displayed on a computer-controlled TV monitor elicited optokinetic eye movements. The first test established three results. First, non-verbal infants can be successfully screened, the one baby known to be colorblind was readily identified. Second, the equiluminance point for red and green was shifted for protans, who needed more red light than normals to make an equiluminance match. Third, the relative contribution of R- and G-cones to the luminance pathways is already in place at the adult level within the first three months of life. The second test, run only on adults, correctly diagnosed deutans who were missed by the first test, and showed that opponent-color mechanisms contribute directly to motion for normal but not for color-deficient observers.