Long-Term Memory for Context-Specific Category Information at Six Months

Abstract

The ability of 6-month-old infants to remember a functional category acquired in a specific context was assessed in 3 experiments via an operant procedure in which infants learned to perform a specific action (a footkick) to activate an object suspended before them. In Experiment 1, infants trained with different exemplars in the same context transferred responding to a novel exemplar in the same but not a different context 24 hours later. Experiment 2 revealed that infants' reactivated memory of category training remained intact and context-specific after 3 weeks. In Experiment 3, a novel category exemplar was able to reactivate the forgotten memory of category training only in the encoding context. At 6 months, information about the place where categories are constructed is prerequisite for retrieval of a category concept from long-term memory. This requirement insures that early category concepts remain stable over relatively long periods.

Contextual updating of infants' reactivated memories

“…These data reveal that exposing infants to a novel context immediately after a reactivation treatment does not interfere with either the reactivation process or with the subsequent expression of the reactivated memory in the original context. Previous research has shown, however, that when an otherwise effective reminder is presented in a novel context during a reactivation treatment, the memory reactivation process is precluded (Borovsky 8z ; Shields & Rovee-Collier, 1992). The present data indicate, therefore, that (a) infants could perceptually distinguish that the two contexts occurred in succession as two discrete events (i.e., that the mobile was in one context before it was in the other), and (b) memory reactivation was initiated-probably instantaneously-by the first event, independent of the second.…”

“…Infants' newly acquired and reactivated memories, like those of rats, are both severely disrupted by contextual change ; Butler & Rovee-Collier, 1989; Shields & Rovee-Collier, 1992). Although their newly acquired memories are likewise modified by information that is encountered after training is over (Muzzio, 1994; RoveeCollier, Borza, Adler, & Boller, 1993), the relative ease with which their reactivated memories are modified by the same information is not known.…”

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

“…On occasion, however, novel stimuli are effective retrieval cues. This occurs when, for example, infants (a) selectively attend to features that are shared by the original stimulus and the novel one (Rovee-Collier, Hankins, & Bhatt, 1992), (b) are explicitly trained with a series of discriminably different mobiles (Fagen, Morrongiello, Rovee-Collier, & Gekoski, 1984;Hayne, Rovee-Collier, & Perris, 1987;Shields & Rovee-Collier, 1992), (c) are exposed to a novel mobile (postevent information) after training is over (Boller et al, 1995;Greco, Hayne, & Rovee-Collier, 1990;Rovee-Collier, Borza, Adler, & Boller, 1993), and (d) have forgotten the specific details of the original stimulus (Riccio et al, 1992;Rovee-Collier & Sullivan, 1980). Under all of the preceding conditions, the novel test mobile is treated as functionally equivalent to the training mobile (see Riccio et al, 1992).…”

“…For 3-month-old human infants, changing the context at the time of testing has no impact on retention after 1 day (Butler & RoveeCollier, 1989;Hayne, Rovee-Collier, & Borza, 1991) but impairs it after longer delays (Butler & RoveeCollier, 1989;Rovee-Collier, Griesler, & Earley, 1985). At 6 months, a context change impairs retention after both 1 day and 3 days but has no effect on retention after longer delays (Borovsky & Rovee-Collier, 1990;Shields & Rovee-Collier, 1992). At both ages, training in one room and testing in another one has the same effect as training in the presence of a distinctive cloth panel and testing in the presence of another one (Borovsky & Rovee-Collier, 1990;Butler & RoveeCollier, 1989;Hartshorn & Rovee-Collier, 1997;Hayne et al, 1991).…”

Developmental changes in the contextual control of recognition

“…Butler & Rovee-Collier, 1989;Hayne, Rovee-Collier, & Borza, 1991;Richardson et al, 1988;Smith, Glenberg, & Bjork, 1978).…”