Abstract

In adults, the pupil shows a sharp transient constriction to isoluminant chromatic exchanges. Red → green and green → red exchanges produce constrictions of about equal magnitude in normal adults but markedly different responses in adult protanopes and deuteranopes. In this study, pupillary responses were recorded from infants while they were looking at 20° schematic video faces that appeared green or red to normal adults. Ten infants were run in each age group, and each infant's responses were averaged within conditions. Three- and 7-week olds showed substantial pupillary constrictions to red → green exchanges but generally not to green → red exchanges. Most 11-week olds showed clear constrictions to both directions of exchange. Additional conditions showed that infants of all ages had clear constrictions to intensity increments produced by changing a dark face to a bright green one.

© 1987 Optical Society of America