Young infants' long-term auditory memory: evidence for changes in preference as a function of delay.

Infants' preferences for a novel or familiar nursery rhyme were examined as an index of long-term memory. One-to 2-month-old infants' preference were tested, using a nonnutritive sucking, discrimination-learning procedure, at 1, 2, or 3 days after the last of multiple familiarization sessions. A consistent novelty preference was observed at the 1-day retention interval, no consistent preference occurred at the 2-day interval, and familiarity preference was found following the 3-day interval. This pattern of results is consistent with attentional preference models which interpret novelty and familiarity preferences as reflecting the discrepancy between an external stimulus and the infants' representation of the stimulus. The findings also reveal that infants as young as 1 month of age encoded and subsequently recognized a repeatedly experienced nursery rhyme after a 3-day retention interval.