Sleep stage duration and architecture show no significant correlation with memory change in this nap paradigm¶

Claim · All claims
Evidence · 1 study · causal r1 · q2
Currency · newest study 2025 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? No significant correlations were found between memory change (for all items or any learning condition) and the time or percentage of the nap spent in any sleep stage. → Jing Zhang 2025

Evidence¶

Jing Zhang 2025¶

Jing Zhang, Xiaoning Huo, Hongbo Lv, Jiahua Xu & Xiaofeng Ma. (2025). Offline consolidation mechanisms of the retrieval practice effect: an analysis based on EEG signal characteristics. npj Science of Learning. https://doi.org/10.1038/s41539-025-00349-8

q2 · i? · causal · r1

Null correlational analysis of PSG sleep statistics against recall change rate across all three learning conditions in the nap group; all printed p values exceed 0.10. No equivalence test was reported.

"There were no significant correlations between change in memory (for either all items or any of the three encoding strengths) and time or percentage of the nap spent in any sleep stage (all p values > 0.10)"

Discussion¶

Learner Variables¶

• Long-Term Memory — outcome: instruction changes it
• Sleep — predictor: learners who differ on it differ in outcomes

Related Claims¶

• Longer NREM periods in a short nap negatively correlate with subsequent encoding performance, possibly due to sleep inertia — reports the opposite
• Percentage of stage 1 sleep positively correlates with encoding performance in an exploratory analysis — related
• A short pre-lesson nap improves immediate memory encoding of a biology lesson in high-school students — related
• Polysomnographic sleep parameters did not differ between afternoon- and evening-trained groups and did not correlate with memory consolidation measures — related
• Wake groups show greater recall-change differences between learning conditions than nap groups, driven by no-feedback items — related