Continuities in infant memory development

Abstract

Fifty-five 6- to 7-month-old human infants were trained in an operant conditioning procedure, adapted from a procedure developed for 3-month-olds, in which kicks were reinforced by conjugate movement of a mobile. Retention was assessed in a simple forgetting paradigm (Expt. 1) or in a reactivation paradigm (Expt. 2) with either the training mobile or a different one serving as the retrieval cue. In Experiment 1, retention was tested 1, 7, 14, or 21 days after training. When the training and test mobiles were the same, infants exhibited virtually no forgetting for 14 days, but forgetting was complete by 21. When the training and test mobiles were different, infants exhibited no retention, discriminating the novel mobile for as long as they could remember the contingency. In Experiment 2, when the training mobile was presented as a reminder, the forgetting previously seen after 21 days was alleviated; when a different mobile was the reminder, it was not. These findings reveal that the efficacy of a reminder is predicted by the efficacy of that same stimulus in cuing the original memory 24 hr following training. Although the 6-month-olds learned more rapidly and remembered longer than infants half their age, their memory processing was described by the same basic principles.

Bidirectional priming in infants

“…In contrast, forgetting and reactivation control groups exhibited no evidence of retention whatsoever. An identical result was obtained with 6-month-olds in the same task (Hill, Borovsky, & Rovee-Collier, 1988), with 6-to 18-month-olds in a task in which lever-pressing moved a miniature train around a circular track (Hartshorn & Rovee-Collier, 1997;Hildreth & Rovee-Collier, 1999Sweeney & Rovee-Collier, 2000), and with 14-to 18-month-olds engaged in multiple activities in a laboratory setting (Sheffield & Hudson, 1994).…”

Levels‐of‐Processing Effects in Infant Memory?

“…Three-month-olds typically double or triple their operant levels within 3-6 min of the introduction of reinforcement; their increased response rate is due solely to the contingency and not to behavioral arousal (e.g., Hill, Borovsky, & Rovee-Collier, 1988;Rovee & Rovee, 1969;Rovee-Collier, Morrongiello, Aron, & Kupersmidt, 1978). (Tukey, 1979).…”

Developmental changes in the specificity of memory over the first year of life

“…The answer to this question is particularly important because recent studies of deferred imitation during the 2nd year of life have presented evidence that infants 12 months of age and older are generally insensitive to cue and context changes (Barnat, Klein, & Meltzoff, 1996;Hanna & Meltzoff, 1993;Hayne, MacDonald, & Barr, 1997), whereas evidence from mobile studies indicates that, after the same absolute delays, infants 6 months of age and younger are highly sensitive to such changes (Boller, Grabelle, & RoveeCollier, 1995;Borovsky & Rovee-Collier, 1990;Butler & Rovee-Collier, 1989;Gulya, 1996;Hill, Borovsky, & Rovee-Collier, 1988;Merriman, RoveeCollier, & Wilk, 1997). The present experiments, therefore, were designed to complete this picture for the last half of infants' 1st postnatal year and then to provide a systematic analysis of the effect of cue and context changes on infants' memory performance over the entire 1st year of life.…”