BOGART, ADAM R., AUG 2011 PSYCHOLOGY
VARIED SUSEPTIBILITY OF REACTIVATED MEMORIES TO RETROGRADE AMNESIA (97 pp)
Director of Dissertation: David C. Riccio
The present series of experiments was an examination into the effects of repeated reconsolidations of a fear memory. Reconsolidation is provoked in the laboratory by re-exposure of the animal to the context it was trained in. This is known as reactivation.
It is important to determine whether each reconsolidation provides additional strength to the memory, or weakens it since many behavioral scientists hold the belief that reconsolidation and extinction have many commonalities.
In Experiment 1, the effect of one to three reactivations in a Passive-Avoidance chamber was examined. The reactivations were given 10 minutes apart. It was found that the second and third reconsolidation were immune to the retrograde amnesia produced by hypothermia.
Differences in the spacing of reactivations might introduce changes in a reconsolidated memory’s propensity to develop retrograde amnesia. Thus, Experiment 2 was identical in all respects to Experiment 1 except the intertrial interval was increased to 24 hours. The findings that fear memories in the twice and thrice reactivated groups were still no longer susceptible to retrograde amnesia with 24 hour spacing between reactivations necessitated a 3rd experiment to determine why.
Experiment 3 showed that if small changes in the configural elements of the training context were made, repeated reconsolidations would generate a memory susceptible to RA.
Consideration of the lack of behavioral changes subsequent to great variation of the intertrial interval in Experiments 1 and 2, while large changes in behavior resulted from small configural changes in Experiment 3 suggests clues to the etiology of repeatedly reconsolidated memories becoming resistant to the induction of retrograde amnesia.