12. Sleep on it! Sleep Consolidation Produces Strong Delayed Memory Retrieval much like Immediate Retrieval

Gabby Silone University of Dayton, Carolina Vazquez University of Dayton, Sarah Lawson University of Dayton, Vicki Karpuzska University of Dayton
Faculty Sponsor(s): Susan Davis University of Dayton
Research indicates that memories are strengthened by consolidation, defined as their incorporation during sleep into a previously established memory network (Rasch & Born, 2008; Rasch & Born, 2013). Data indicate that memories are initially unstable after encoding and that sleep consolidation increases resistance to interference of time and other factors (Robertson, 2011). On the first day of a two-day experiment designed to examined whether delay in retrieval after learning would affect later memory consolidation, participants in the present research memorized pictures of common objects (e.g., owl, motorcycle) presented in a slideshow. Participants were assigned to either complete an immediate recognition test of the pictures, or return to lab the following day to complete a delayed recognition test. We tested the hypothesis that target pictures tested for memory only on the second day would be remembered at least as good if not better, due to sleep consolidation, than when tested for memory only on the first day. A second hypothesis was that participants would differ in their performance in discriminating lures from targets, depending on whether recognition was tested on the first or second day, after sleep. A 2 (Test day: Day 1 and 2) x 2 (Test stimulus: Targets and Lures) ANOVA compared correct discrimination on Day 1 and 2 between studied target pictures and tested lure pictures.
There was a significant interaction between test stimuli and day of testing, F(1, 50) = 11.664, p = .001. The strength of the effect of the interaction, as indexed by eta2 was .189. There were also main effects of test stimulus and testing day (p < .05, for each effect).
Participants tested on Day 1 were as correct as those on Day 2 in identifying picture targets. This indicates that sleep consolidation has an overall effect of maintaining the strength of memory over time. However, participants on Day 2 were less accurate than those on Day 1 in discriminating lures from targets. Data to be studied involves repeated testing on Day and Day 2 and is expected to verify these observations.
Analyses to examine serial position effects on sleep consolidation as a function of a task interruption and their effect on sleep consolidation are in progress.
Poster Presentation

When & Where

Irwin Library Lower Level