Promoting memory consolidation during sleep: A meta-analysis of targeted memory reactivation.
Level 1 - systematic review of randomized trials
Meta-analysis of 91 experimental trials
PubMed 32027149 · doi:10.1037/bul0000223
What was done
A meta-analysis was conducted using multilevel modeling across 91 experiments with 212 effect sizes (total N = 2,004) to evaluate the effect of targeted memory reactivation (TMR) on memory consolidation during sleep and wakefulness. Subgroup analyses evaluated sleep stages (NREM 2, slow-wave sleep, REM), wakefulness, memory domains (declarative memory, skill acquisition), and publication bias.
What was found
Overall sleep TMR significantly enhanced memory consolidation (Hedges' g = 0.29, 95% CI [0.21, 0.38]). By stage, significant effects were observed for NREM Stage 2 (Hedges' g = 0.32, 95% CI [0.04, 0.60]) and slow-wave sleep (Hedges' g = 0.27, 95% CI [0.20, 0.35]). TMR was not effective during REM sleep or during wakefulness. Memory improvements were observed for both declarative memory and skill acquisition.
Why it matters
This meta-analysis provides quantitative evidence that cueing memories specifically during NREM sleep promotes consolidation, validating TMR as an experimental tool and potential cognitive intervention.
Limits
The abstract does not specify participant demographics, long-term durability of the consolidated memories, stimulation protocols (e.g., auditory vs. olfactory cues), or individual study risk-of-bias metrics.
Cited by
- partial Re-presenting olfactory cues during sleep that were previously paired with learning material produces a doubling in memory retention benefit.