JOURNAL OF EXPERIMENTAL CHILD PSYCHOLOGY 68, 22–34 (1998) ARTICLE NO. CH972407 Human Newborn Color Vision: Measurement with Chromatic Stimuli Varying in Excitation Purity

Groups of newborn human infants (N 180) were habituated to large 167 achromatic (‘‘white’’) lights of varying luminance (0.35 to 1.16 log cd/m2) and then tested for recovery of habituation to 167 green (dominant l 545 nm), yellow (dominant l 585 nm) or red (dominant l 650 nm) lights which varied in the level of excitation purity (range 32 to 83%). Results showed that newborns discriminated the chromatic stimuli from white only when excitation purity values exceeded at least 41 % for 545-nm green, 47 % for 650-nm red, and 65 % for 585-nm yellow, limits much higher than those for adults (1%). Taken together with the results from previous experi-ments, these saturation discrimination data (with the exception of the yellow data), provide some support for an expanded MacAdam ellipse model of early color dis-crimination (Brown, 1993; Teller & Lindsey, 1993). This helps reinforce the current view that neonates ’ vision is based on general rather than selective immaturities or inefficiencies within the requisite optical, photoreceptoral and neural mech-anisms. q 1998 Academic Pres