From the Research
At least one full night of quality sleep is required for new information to be consolidated into long-term memory, with more complex information potentially benefiting from multiple consecutive nights of good sleep. This is based on the most recent and highest quality study available, which suggests that sleep plays a crucial role in memory consolidation, particularly during slow-wave and REM sleep 1. The study published in 2022 in Neuroscience and biobehavioral reviews, challenges the notion of "sleep-dependency" and proposes that it is not sleep per se, but the engagement of plasticity mechanisms, active during both sleep and waking states, that constitutes the critical factor determining memory formation.
Key Findings
- Sleep benefits the consolidation and reorganization of learned information 1
- Plasticity mechanisms thought to mediate or facilitate consolidation during sleep also operate during non-sleep states, particularly quiet wakefulness 1
- Sleep deprivation significantly impairs memory consolidation, which is why cramming the night before an exam is less effective than spaced learning followed by proper sleep 2
- The hippocampus replays the day's experiences and transfers them to the neocortex for permanent storage during sleep, particularly during slow-wave and REM sleep 3
Recommendations
- Study important information before bedtime to allow for optimal memory consolidation during sleep
- Get 7-9 hours of quality sleep to ensure adequate slow-wave and REM sleep
- Consider reviewing the material again the following day to further strengthen the memory connections
- Avoid sleep deprivation, as it can significantly impair memory consolidation and cognitive function
Limitations
- The exact number of nights required for long-term memory consolidation may vary depending on the complexity of the information and individual differences in sleep and cognitive function
- More research is needed to fully understand the mechanisms underlying sleep-dependent memory consolidation and the optimal sleep patterns for cognitive longevity 3