Two of the most effective study techniques are spaced learning and sleep. Spaced learning (or distributed practice) is when learning is spaced out over multiple sessions rather than presented in one long session. Sleep, on the other hand, has many learning benefits. After sleep, newly learned information becomes more stable thereby enhancing learning. The goal of the current study was to determine if combining both strategies could lead to better learning.
The study had 3 parts, the studying session, relearning session, and delayed testing (1 week and 6 months later). In the studying session, participants read 16 Swahili-French word pairs (nyanya-tomate) and then studied each word (given nyanya-____, what is the French translation?). For words they recalled incorrectly, the correct translation was shown, and participants practiced until they got all 16 correct. The relearning session happened 12 hours later and proceeded in a similar way. Delayed testing occurred 1 week and 6 months later. Participants were divided into 3 groups: (i) sleep group: studied at 9 pm, slept, and then relearned at 9 am the next day; (ii) no sleep group: studied at 9 am and relearned at 9 pm on the same day; and, (iii) control group: studied at 9 pm, slept, and then completed a recall-only session at 9 am the next day. Findings revealed that sleeping after learning (sleep and control groups) led to better retention the next day than not sleeping (no sleep group). Further, the sleep group required fewer trials to successfully recall all 16 pairs correctly than the no sleep group (i.e., relearning happened faster). Strikingly, the benefits of sleep and relearning were amplified 1-week later and were maintained 6-months later: only the sleep group remembered significantly more word pairs than both the no sleep and control group.
The results suggest that sleeping after learning is a good strategy but additional learning after sleep is especially beneficial to long-term memory. It would follow from these findings that it would be beneficial to children’s learning if a clinician could introduce new learning in therapy one day and then incorporated a re-learning phase (perhaps with home practice materials) after sleep the next day.