Memory reactivation during REM sleep promotes its generalization and integration in cortical stores
Reading this paper because I’m interested in how lucid dreaming can be used to promote learning. Lucid dreaming can be viewed as a form of “memory reactivation” but would likely be restricted to REM, and so I’m curious about the current status of REM-TMR effects. I came across some papers showing no effect of TMR in REM, but this paper looks neat as it shows a certain type of learning other than those typical of NREM TMR. Also it’s fMRI :)
The gist of the experiment is that they scanned participants during encoding and a recognition task, while receiving REM-TMR in-between. There were tones associated with pictures during encoding. There was an aspect of the study where the effects of high/low emotion pictures were investigated separately, but these effects were generally absent of weak if present at all.
They had four conditions (cuedREM / cuedN2 / nocue / cuedREM without encoding cues). There’s a really cool behavioral result where participants that got cued in REM (and cued during encoding) showed more “generalization errors” during the recognition test. This is the claim after finding that there was in increase in false alarms (and correct recollections). It feels tempting to talk this off as being a simple increase in “old” responses, but there are so many control conditions that it feels legitimate. The neural finding linked to this is that during retrieval, even though all conditions show activation in a broad ‘memory network’, the cuedREM condition showed the most in two areas that were relevant (based on past lit) to face perception and multi-sensory convergence. With some reverse inference, they draw the conclusion that this supports a notion of generalized memory representations after encoding.
A cool sidenote is that they used actigraphy and sleep diaries to ensure participtants followed a regular sleep schedule for four nights before the study. This might be a popular thing in overnight sleep studies, but I wasn’t familiar with it before.