Order and duration of stimuli are important determinants of reactivation

Abstract

Prior cuing treatments intended to alleviate the forgetting of a conditioned aversion to an odor were tested with 18-day-old rats. Previous experiments had shown that when such pups were conditioned with the use of a CS-/CS+ procedure, pretest presentation of the CS-or US, but not the CS+, alleviated the forgetting otherwise seen after a 3·h retention interval. In Experiment 1, it was determined that the forgetting was not alleviated if the CS-was either preceded or followed by presentation of the CS+, despite the fact that the CS-/CS+ ordering mimicked that of original conditioning. Experiment 2 was an examination of the balance of extinction and reactivation effects caused by presenting the CS+ for varying durations following the 3·h retention interval. The forgetting over this interval was alleviated if the CS+ was presented for 5 or 15 sec, but not 30 sec. With an increase in duration of exposure from 15 to 30 sec, the consequences of the CS+ as a prior cuing treatment apparently shifted from reactivation to extinction. Experiment 3 was a test of the interaction between the consequences of different lengths of CS+ exposure and the effectiveness of adding CS-to the CS+ as a reactivation treatment. The varied effectiveness of reactivation treatments is discussed in terms of a change in stimulus conditions from training to reactivation.The necessary and sufficient conditions for the alleviation of forgetting remain unsettled in memory research. One effective treatment in the alleviation of forgetting is the presentation of a reminder, or prior cue. Many authors have noted the importance of such procedures, which are typically referred to as reactivation treatments (Gordon, 1981(Gordon, , 1983 Rovee-Collier, Sullivan, Enright, Lucas, & Fagen, 1980;Spear, 1978;Spear, Miller, & Jagielo, 1990;Spear & Parsons, 1976). A reactivation treatment involves exposing the subject to a specified aspect of the original training episode prior to a retention test. Reactivation treatments have been used to alleviate forgetting that results from many different sources, such as long retention intervals (Gordon, Smith, & Katz, 1979;Spear & Parsons, 1976), short retention intervals (Feldman & Gordon, 1979;Gordon & Feldman, 1978), and electroconvulsive shock (R. R. Miller & Springer, 1973). Reactivation treatments have also been shown to alleviate forgetting in preweanling animals (Campbell & Jaynes, 1966) and in human infants (Rovee-Collier et al., 1980).In a recent series of experiments, J. S. Miller, Jagielo, and Spear (1989Spear ( , 1991 McKinzie for their comments on an early version of the manuscript. We would also like to thank Teri Tanenhaus for secretarial assistance in preparing the manuscript, Norman Richter for technical assistance, and Heather Rabine for assistance in collecting the data. Requests for reprints may be addressed to N. E. Spear, Center for Developmental Psychobiology, Binghamtom University, Binghamton, NY 13902. rats were exposed to a lemon odor (CS -) prior to the pairing of a second odor, methyl salicy...

Effects of priming duration on retention over the first 1½ years of life

“…Despite the large difference in the interval between training and priming, the minimum duration of priming actually decreased from 120 s to 1.5 s over this age range. These priming durations fall well within the range of durations that have been used with both animals and human adults (Arnold & Spear, 1993;Deweer & Sara, 1984;Gordon et al, 1979;Musen, 1991;Schacter et al, 1991), indicating that the phenomenon presently observed is neither species nor task specific.…”

“…They hypothesized that memory reactivation had begun at the time of exposure to the reactivation stimulus and that once the memory was reactivated, the continued presence of the reactivation stimulus had led to extinction. Similarly, Arnold and Spear (1993) found that exposing 18-day-old rat pups to the CSþ for 5 s or 15 s reactivated their forgotten memory of a learned avoidance response, but exposing them to the CSþ for 30 s did not.…”

Early Responsiveness to Stimuli Paired With Different Stages Within the State of Alcohol Intoxication

“…Notice that when the texture CS was presented for a shorter period of time and 5 min elapsed between that CS and the intake test, and an alternative tactile stimulus was available during the texture preference tests (group T-I, experiment 1), no effects were obtained in terms of the magnitude of the tasteaversive response. The amount of exposure to a given cue originally involved in the learning situation, the delay existing between re-exposure to this cue and the testing situation, and the similarity between the nature of the elements that define the learning situation and the re-exposure treatment represent critical variables in terms of determining reactivation processes of the memory under analysis (Miller et al, 1991;Moore Arnold and Spear, 1993;Richardson et al 1993).…”

“…The possibility of tactile conditioning was also evaluated. Re-exposure to some of the elements that defined the original learning episode were likely to affect the expression of a given conditioned response through processes such as extinction or reactivation of specific memory contents (Miller et al, 1991;Moore Arnold and Spear, 1993;Spear and Riccio, 1994). This experiment was designed to allow us to answer whether CS or US re-exposure facilitates the expression of texture-or tasterelated memories, or both.…”

Minimum duration of reactivation at 3 months of age

“…Subsequently, Arnold and Spear (1993) manipulated the duration of a reactivation treatment with 18-day-old rat pups. They conditioned pups to associate a particular odor with foot shock and, 3 hr after training, exposed the pups to the aversive odor for 30 s (the reactivation treatment).…”