Evidence for a transitional period for development of persistence in infant rats.

Abstract

Four experiments point to the existence of a transitional period in neonatal rats for the learning of persistence. Partial reinforcement training with suckling on an anesthetized dam as reward induced greater persistence in extinction of the approach response than did continuous reinforcement in rat pups 14 days old but not in 11 day old pups. Other aspects of this period of development are discussed.