Sleeping on it: Does Interference during Encoding Reduce Sleep Consolidation of Memory?

Indianapolis, IN

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 (Robertson, 2011). On the first day of a two-day experiment designed to examine whether interrupting the encoding of a memory would affect later memory consolidation, participants in the present research memorized pictures of common objects (e.g., owl, motorcycle) presented in a slideshow. At the midpoint of the slideshow, there was a simulated computer crash. While the experimenter pretended to amend the fake situation, participants completed an unrelated task to prevent rehearsal of the pictures. Shortly after, the slideshow resumed, presenting the remaining pictures. Participants were assigned to either complete an immediate recognition test of the pictures, return to lab the following day to complete a delayed recognition test, or complete both an immediate and a delayed recognition test. We hypothesized that pictures that appeared near the beginning and the end of the encoding, and those that appeared after the resumption of the interrupted slideshow would be better remembered than those pictures that appeared just before the interruption. We also expected that participants tested on the second day would be less confident in their assessment of their memory of the pictures, but would recognize just as many pictures, if not more, than those participants tested on the first day of the experiment.