Dissipation of retroactive interference in human infants.

Abstract

In 3 experiments with 85 human 3-month-olds, the authors asked whether retroactive interference with their memory of the original training stimulus is temporary or permanent. Infants learned to move a mobile by kicking and then were exposed to a different mobile (Experiment 1) or context (Experiment 2) immediately or 3 days afterward (Experiment 3). They were tested after increasing delays with the original stimulus, the exposed stimulus, or a completely novel stimulus. Retroactive interference was temporary and unrelated to the exposure delay. The data are consistent with a retrieval-based account of interference. Memory updating (i.e., responding to the interfering stimulus) was coincident with retroactive interference, suggesting that retroactive interference is an adaptive mechanism that facilitates memory updating within a narrow time window.

Updating reactivated memories in infancy: II. Time passage and repetition effects

“…A closer look at the infant data, however, revealed that passive exposure to novel information permanently modified the original training memory only when it was older (Boller et al, 1996;Muzzio & Rovee-Collier, 1996;Rovee-Collier et al, 1994). What had initially seemed to be a memory modification resulting from passive exposure to novel information shortly after training (Rovee-Collier et al, 1993) turned out to be a relatively transient retroactive interference phenomenon (Gulya et al, 2002;Rossi-George & Rovee-Collier, 1999). Likewise, in the present study, passive exposure to novel information permanently modified the reactivated memory only when it was older.…”

“…As a result, the reactivated memory is resistant to modification shortly after reminding (Galluccio, 2005), just as the original memory is resistant to modification shortly after training (Gulya et al, 2002;Rovee-Collier et al, 1994). Also like the original memory, the reactivated memory is more malleable when it is older (i.e., when more time has elapsed since its initial reactivation).…”

“…The main distinction between the vulnerability of infants' reactivated and original memories seems to be their malleability by novel information that is presented via a passive-exposure procedure. When this procedure is administered immediately after original training, it leads to interference with the original memory; when it is administered several days afterward, it leads both to interference and modification (Gulya et al, 2002;Rovee-Collier et al, 1994;Rovee-Collier et al, 1993). In contrast, when the same procedure is administered immediately after a reactivation treatment, it has no effect (Galluccio, 2005).…”

Updating reactivated memories in infancy: I. Passive‐ and active‐exposure effects

“…If the retrieval deficit is transient, then the original memory is rendered temporarily inaccessible; however, after a longer delay the interference dissipates, and the original memory can again be retrieved. Gulya et al (2002) found that passively exposing 3-month-olds to a novel mobile immediately after training (without a distinctive context) led both to interference with and modification of their training memory 1 day later. When infants were tested 2 days later, the interference had dissipated, but they still recognized the novel exposure mobile.…”

“…When the exposure occurred shortly after training, it retroactively interfered with infants' subsequent recognition of the original training mobile and context; that interference eventually dissipated, and recognition of the original mobile was recovered (Gulya, Rossi-George, & Rovee-Collier, 2002). But when the exposure occurred after a longer delay, the details of the novel mobile or context were substituted for those of the original training mobile or context, resulting in a permanent memory modification (Boller, Rovee-Collier, Gulya, & Prete, 1996;Rovee-Collier, Adler, & Borza, 1994).…”