Ontogeny of early event memory: II. Encoding and retrieval by 2- and 3-month-olds

Infants' eyewitness testimony: Effects of postevent information on a prior memory representation

“…In all respects, their performance mirrored that of Group AAb/ A in Experiment 3 (see Figure 5, top panel). In previous research with the same mobiles but in which no postevent information was introduced, infants had similarly failed to recognize their training mobile if more than a single novel object had been substituted into it (Hayne, Greco, Earley, Griesler, & Rovee-Collier, 1986;Rovee-Collier, Patterson, & Hayne, 1985). The considerable specificity required of effective retrieval cues at this age, therefore, encourages us to reject the memoryblend alternative: Had the test mobile matched the representation in long-term memory, infants would have recognized it.…”

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

“…The effect on retention of changing the original focal cue at the time of testing has been studied with 2-to 6-month-olds in the mobile conjugate reinforcement paradigm (Butler & Rovee-Collier, 1989;Gulya, 1996; Hayne et al, 1986;Hill et al, 1988;Merriman et al, 1997;Rovee-Collier, Earley, & Stafford, 1989;Rovee-Collier & Sullivan, 1980) and with 12-to 21-month-olds in the deferred imitation paradigm (Hayne et al, 1997). The results of these studies differ markedly, but whether the differences are due to differences in age or in paradigm is unclear.…”

“…Moreover, the cues that are required to retrieve their memory of the training stimulus are highly specific. At both 2 and 3 months, for example, infants exhibit no retention whatsoever if more than a single novel object is substituted into the original five-object mobile during a 1-day test (Fagen, Rovee, & Kaplan, 1976;Hayne et al, 1986), and at 3 months, they exhibit no retention after the same delay if the ϩ on the sides of the training mobile is only 25% smaller (Adler & Rovee-Collier, 1994).…”

Generalization of deferred imitation during the first year of life

“…Not only can 3-and 6-month-olds perceptually diVerentiate between their training and test stimuli after 24 h Bhatt, Rovee-Collier, & Shyi, 1994;Fagen, Rovee, & Kaplan, 1976;Fagen, Yengo, RoveeCollier, & Enright, 1981;Hayne, Greco, Earley, Griesler, & Rovee-Collier, 1986;Rovee-Collier & Capatides, 1979), but they also can remember the speciWc details of their training stimuli for periods ranging from several days at 3 months of age to 2 weeks at 6 months of age (Bhatt & Rovee-Collier, 1996;Borovsky & Rovee-Collier, 1990;Hill, Borovsky, & Rovee-Collier, 1988;Muzzio & Rovee-Collier, 1996;RoveeCollier & Sullivan, 1980). Despite the speciWcity and accuracy of their memories, 3-and 6-month-olds can also exhibit acquired equivalence and generalize to novel cues and contexts if they have encountered at least two diVerent cues or contexts previously.…”