This paper describes a series of studies investigating the effects of memory reactivation in early infancy. Twelve-week-old infants were taught a footkick response by having one leg tied to an overhead crib mobile so that each footkick produced movement of the mobile (reinforcer). Retention of the footkick response was assessed after 6, 8, and 14 days and rates of forgetting were determined. The effects of memory reactivation in counteracting the forgetting were then examined. Reactivation consisted of placing the infants under the mobile without attaching the ribbon to their leg, so that they could be exposed for 3 minutes to the reinforcer (movement of the mobile) independent of their response (footkick). Results showed that this reactivation was sufficient to bring the level of footkicks back to its level on the original retention test immediately following initial training. Further results showed that the effects of reactivation were greatest at 24 hours after reactivation. Thereafter, forgetting was shown to occur at about the same rate as the forgetting of the initial learning. Further investigation showing that reactivation was facilitated by periods of sleep was interpreted as suggesting that infant memory is more accessible for reminiscence during periods of minimal interference. (Author/JMB)