A study has found that toddlers nap when their brains are ready rather than at a certain age, and experts are urging parents to put their children to sleep.
Naps are known to be critical for brain development and memory processing, but scientists still don’t know when and why young children stop taking naps.
Professor Rebecca Spencer of the University of Massachusetts is leading an investigation into why some four- and five-year-olds enjoy taking daily naps, while some three-year-olds stop.
The findings, “Association between nap transitions and underlying memory and brain development,” were published in the Proceedings of the National Academy of Sciences by Professor Spencer of the University of Maryland and co-author Tracy Riggins.
Professor Spencer added: “When young children nap, they consolidate affective and declarative memories, so you ask yourself, when it’s such an important time for learning, if naps help learning, why do they get away from it? The nap transition? Why not just keep the nap?”
The study focused on the brain’s hippocampus, which plays an important role in developing learning and memory.
Their previous work showed differences in hippocampal development between children who napped and those who stopped napping.
When a young child’s hippocampus is immature, it reaches the limit of memory that can be stored without being forgotten, triggering the need for sleep, the authors say.
Naps allow these memories to be processed to the cortex of the brain, freeing up space in the hippocampus to store more when they wake up.
“When the hippocampus is inefficient, it’s like having a little bucket — your bucket fills up and overflows faster, and some memories overflow and get forgotten,” Professor Spencer said.
“That’s what we think happens to kids who are still napping. Their hippocampus is less mature, and they need to empty that bucket more often.”
When the hippocampus is more developed, children can stop napping because their hippocampus has matured to the point where their “bucket” doesn’t overflow.
The suggestion was that they were able to retain memories until the end of the day, and sleep at night could transfer memories to the cerebral cortex.
Professor Spencer said there was growing evidence that it was important to give all young children the opportunity to nap.
But she said further research is now needed to track children over time.
Forcing children to stop taking naps “may lead to poor learning and memory,” she added.