Rapid and Enduring Associative Connections: Ontogenetic Differences in Minimal Conditions for Learning Transfer at 6 and 9 Months.

Associations can enhance memory flexibility by enabling infants to transfer learning from one cue to another. The present experiment combined sensory preconditioning and deferred imitation to investigate the minimal conditions under which 6- and 9-month-olds form associations between co-occurring stimuli without exogenous reinforcement and retain this information for at least 48 h. Six-month-olds demonstrated robust learning transfer 2 days after a single 1-min, 52-s exposure to two stationary puppets in their visual surround. A single 56-s exposure or two 56-s exposures on consecutive days were ineffective. Nine-month-olds showed learning transfer after substantially longer exposure that involved stimulus movement (15 min). Additionally, age-related differences emerged in the conditions that supported learning; 6-month-olds rapidly formed and retained associations following simultaneous exposure, whereas 9-month-olds did so only after sequential exposure. These findings highlight ontogenetic differences in the constraints of associative learning and are discussed in relation to domain-general learning mechanisms.