Abstract
We previously investigated chromatic and luminance contrast sensitivity (CS) in preterm and fullterm infants (JOV, 2009). Here we analyze a larger sample of 104 preterm and 148 infants between 1–8.5 months postnatal age (PNA). We hypothesized the maturational effect of PNA (of which visual experience is a large component) may depend upon when infants were born relative to due date (which is linked to biological maturity). We pooled all infants together and analyzed the effect of PNA (Groups: 2, 3, 4, 5, 6, and 8 mos) and “gestational age (GA)-at-birth” (Groups: −10 to −8, −7 to −5, −4 to −2, −1 to 0, and +1 to +3 weeks around due date). ANOVA results revealed significant interactions between PNA and GA-at-birth for both luminance (p = 0.003) and chromatic (p = 0.004) CS. At 2 and 3 mo (equivalent to 0.7 and 1.8 mos postterm age), both luminance and chromatic CS were worse for infants with lower GA-at-birth than those near-term, but by 6 and 8 mos, infants with the lowest GA-at-birth surpassed other groups. Results suggest an interesting beneficial “sleeper” effect of early postnatal visual experience, which has been reported for detrimental effects of congenital cataracts (Maurer et al., 2007).