Forgetting is often perceived as the inability to retain information, but in fact at least some memory deterioration is due to active suppression processes, that are behaviorally adaptive. These active processes are thought to involve new, inhibitory learning, suggesting that sleep may serve to enhance them as it does other forms of learning. If this were the case, sleep may be harnessed to weaken non-adaptive memories in a manner that may be beneficial for healthy and clinical populations suffering from memory-related symptoms of disorders such as post-traumatic stress disorder (PTSD). To test this idea, this suggested nap study will incorporate specific memories in a suppression context during sleep monitored by encephalography (EEG). First, participants will take part in an item-based directed forgetting task, in which they will be exposed to different words, immediately followed by instructions to either remember the preceding word or not. The instructions will be conveyed using two distinct odors. In fact, the purpose of this first part would be to cement the associations of these odors with the instructions. Next, in an unrelated task, participants will learn the spatial locations of images on a screen. These images will be presented along with congruent sounds (e.g., cat - meow). During a subsequent nap, some of these sounds will be unobtrusively presented along with one of the two previously learned odors or along with a novel odor. In a final spatial-location test, memory for the images whose sounds were presented along with the "forget" odor during sleep is expected to be worse than for the images that were not cued. Memory for the locations of the images whose sounds were presented with one of the two other odors during sleep are expected to improve, possibly more so for the sounds presented with the "remember" odor relative to those presented with the novel odor. If successful, these results would be a first step towards interventions that may serve to selectively weaken memory during sleep.
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Change in error rates between pre- and post-sleep for the different conditions
Timeframe: Approximately 15 minutes before sleep onset and approximately 15 minutes after sleep offset within the same experimental session
Modulation of EEG spectral power following sound/odor presentation
Timeframe: During sleep within the experimental session, assessed up to 1.5 hours