Study shows like in adults both naps and overnight sleep important for memory in children
Naps and overnight sleep may be crucial for early childhood memories.
In a new study by sleep researchers at the University of Massachusetts Amherst, neuroscientists led by Rebecca Spencer report how important sleep is in children to boost their memories. The study has appeared in Scientific Reports.
“Individually, the nap and overnight sleep bouts were not sufficient to induce changes in memory. A significant benefit of napping was observed only when changes across the entire 24-hour period were considered. This supports an interplay between the nap and subsequent overnight sleep in the consolidation of memories in young children,” the researchers reported.
They say another highlight of their work is finding that naps do contribute to emotion processing in preschool children, which is consistent with parents’ and early childhood teachers’ observations. This benefit in emotional memory, however is delayed, say Spencer and colleagues. This delay may reflect “short-term destabilization of an enriched memory,” they add.
That is, “there may be measurable benefits in behavior, even if not in memories themselves.”
“A common observation of parents and preschool teachers is that children seem either grumpy or giddy when they skip their nap”
“A common observation of parents and preschool teachers is that children seem either grumpy or giddy when they skip their nap,” says Spencer. “Our results are consistent with these observations of caregivers. Naps do contribute to emotion processing at this young age.”
Earlier research in adults has shown that emotion processing and emotional memory are enhanced with sleep. There are suggestions that naps may support emotional regulation and emotional memory for toddlers, as well. But the prevailing “REM sleep hypothesis of emotional processing” says that REM sleep is required for this benefit, and naps lack this sleep stage. Instead, 42 percent of naps in toddlers consist of slow-wave sleep.
Thus the researchers set out to explore whether naps can contribute to memory consolidation for memories with emotional valence – either good or bad emotional content – in early childhood.
Study results were based on the performance of 49 children who were shown emotionally neutral photos of men’s and women’s faces paired with “mean” or “nice” statements, such as “Lena is always nice. Today she helped us pour milk into our cups at lunch time.” Recognition of the familiar face versus an unfamiliar one was tested at three points: immediately after learning, after a delay either with a nap or awake, and again the next day. Children who did not nap were kept awake with quiet play items before the delayed test.
