Forgetting functions of reactivated memories over the first year of life

A reactivation treatment alleviates forgetting by reexposing organisms to an isolated component of the original event. How long a reactivated memory persists, however, has not been studied systematically. Presently, we documented the retention of a reactivated memory with 6-, 9-, and 12-month-old human infants. All infants learned an operant task, forgot it, and then received a brief reactivation treatment 1 week later. They were tested after increasingly longer delays until the reactivated memory also was forgotten. To provide a picture of retention over the entire first year of life, we combined their data with corresponding data previously obtained from 3- and 6-month-olds in an equivalent task. Although the maximum duration of original retention increases linearly between 3 and 12 months of age, infants consistently forgot the reactivated memory at the same rate as the original one over this period. In essence, a reactivation treatment doubles the life of the memory.