Detection of contrast by the newborn and 2-month-old infant

We studied newborns' and 2-month-olds' sensitivity to contrast by taking advantage of their preference for patterned over unpatterned stimulation. Newborns looked longer at checkerboards in which the checks contrasted by 11%, by 17%, by 23%, and by 27% than at gray squares matched in luminance to the checkerboards, but showed no preference when tested with checks contrasting by 3% or by 5%. In addition, the magnitude of the preference increased as a function of increasing contrast. Two-month-olds showed preferences for checkerboards with contrasts of 5%, of 11 %, and of 23%, but not of 3%, over matching gray squares. However, 2-month-olds' preferences did not increase with increasing contrast. The results suggest that newborns are much more sensitive to contrast than previous studies had indicated, and that 2-month-olds are even more sensitive than newborns.