Summary: A new study reports sleep between study sessions may help people retain thier learning and relearn things you have forgotten.
Source: Association for Psychological Science.
Getting some sleep in between study sessions may make it easier to recall what you studied and relearn what you’ve forgotten, even 6 months later, according to new findings from Psychological Science.
“Our results suggest that interleaving sleep between practice sessions leads to a twofold advantage, reducing the time spent relearning and ensuring a much better long-term retention than practice alone,” explains psychological scientist Stephanie Mazza of the University of Lyon. “Previous research suggested that sleeping after learning is definitely a good strategy, but now we show that sleeping between two learning sessions greatly improves such a strategy.”
While studies have shown that both repeated practice and sleep can help improve memory, there is little research investigating how repetition and sleep influence memory when they are combined. Mazza and colleagues hypothesized that sleeping in between study sessions might make the relearning process more efficient, reducing the effort needed to commit information to memory.
A total of 40 French adults were randomly assigned to either a “sleep” group or a “wake” group. At the first session, all participants were presented with 16 French-Swahili word pairs in random order. After studying a pair for 7 seconds, the Swahili word appeared and participants were prompted to type the French translation. The correct word pair was then shown for 4 seconds. Any words that were not correctly translated were presented again, until each word pair had been correctly translated.
Twelve hours after the initial session, the participants completed the recall task again, practicing the whole list of words until all 16 words were correctly translated.
Importantly, some participants completed the first session in the morning and the second session in the evening of the same day (“wake” group); others completed the first session in the evening, slept, and completed the second session the following morning (“sleep” group).
In the first session, the two groups showed no difference in how many words they could initially recall or in the number of trials they needed to be able to remember all 16 word pairs.
But after 12 hours, the data told another story: Participants who had slept between sessions recalled about 10 of the 16 words, on average, while those who hadn’t slept recalled only about 7.5 words. And when it came to relearning, those who had slept needed only about 3 trials to be able to recall all 16 words, while those who had stayed awake needed about 6 trials.
Ultimately, both groups were able to learn all 16 word pairs, but sleeping in between sessions seemed to allow participants to do so in less time and with less effort.
“Memories that were not explicitly accessible at the beginning of relearning appeared to have been transformed by sleep in some way,” says Mazza. “Such transformation allowed subjects to re-encode information faster and to save time during the relearning session.”
The memory boost that participants got from sleeping between sessions seemed to last over time. Follow-up data showed that participants in the sleep group outperformed their peers on the recall test 1 week later. The sleep group showed very little forgetting, recalling about 15 word pairs, compared to the wake group, who were able to recall about 11 word pairs. This benefit was still noticeable 6 months later.
The benefits of sleep could not be ascribed to participants’ sleep quality or sleepiness, or to their short-term or long-term memory capacity, as the two groups showed no differences on these measures.
The results suggest that alternating study sessions with sleep might be an easy and effective way to remember information over longer periods of time with less study, Mazza and colleagues conclude.
Funding: This study was supported by the LABEX CORTEX (Grant ANR-11-LABX-0042) of Université de Lyon, within the program “Investissements d’Avenir” (Grant ANR-11-IDEX-0007), operated by the French National Research Agency (ANR). S. Mazza was further supported by ANR Grant 15-CE33-0003-01.
Source: Stephanie Mazza – Association for Psychological Science
Image Source: This NeuroscienceNews.com image is adapted from the Association for Psychological Science press release.
Original Research: Abstract for “Relearn Faster and Retain Longer: Along With Practice, Sleep Makes Perfect” by Stéphanie Mazza, Emilie Gerbier, Marie-Paule Gustin, Zumrut Kasikci, Olivier Koenig, Thomas C. Toppino, and Michel Magnin in Psychological Science. Published online August 16 2016 doi:10.1177/0956797616659930
Relearn Faster and Retain Longer: Along With Practice, Sleep Makes Perfect
Both repeated practice and sleep improve long-term retention of information. The assumed common mechanism underlying these effects is memory reactivation, either on-line and effortful or off-line and effortless. In the study reported here, we investigated whether sleep-dependent memory consolidation could help to save practice time during relearning. During two sessions occurring 12 hr apart, 40 participants practiced foreign vocabulary until they reached a perfect level of performance. Half of them learned in the morning and relearned in the evening of a single day. The other half learned in the evening of one day, slept, and then relearned in the morning of the next day. Their retention was assessed 1 week later and 6 months later. We found that interleaving sleep between learning sessions not only reduced the amount of practice needed by half but also ensured much better long-term retention. Sleeping after learning is definitely a good strategy, but sleeping between two learning sessions is a better strategy.
“Relearn Faster and Retain Longer: Along With Practice, Sleep Makes Perfect” by Stéphanie Mazza, Emilie Gerbier, Marie-Paule Gustin, Zumrut Kasikci, Olivier Koenig, Thomas C. Toppino, and Michel Magnin in Psychological Science. Published online August 16 2016 doi:10.1177/0956797616659930