Behavioral measurement of background adaptation in infants.

Thresholds for detecting blue test flashes in the dark-adapted condition and on steady red background fields were measured in 2- to 18-week-old human infants by a two-alternative forced-choice preferential looking method. The results show that dark-adapted sensitivity increases and background adaptation develops during the early postnatal weeks. Thus, the retinal mechanism that underlie (1) detection of brief flashes and (2) neural processing in background adaptation appear to mature postnatally.