People spend more of their time asleep as babies than at any other point in their lives, but even if this has been common knowledge for some time we’re only beginning to understand what role sleep plays during this key stage. University of Sheffield researchers claim that sleeping is key to learning and forming new memories for infants as old as 12 months. Babies who didn’t nap were far less able to repeat what they had been taught only 24 hours earlier. The findings aren’t only important for parents looking for advice to manage their babies, though. The researchers draw a parallel between life’s dawn and twilight years, suggesting that more sleep is important for memory consolidation for the elderly and helps keep neurodegenerative diseases like Alzheimer’s at bay. Is napping good or bad? Read on.

Sleeping through our baby years

Trials were performed with 216 babies six to twelve months old. The infants were taught three new tasks involving playing with hand puppets, then divided into two equal groups. Half the babies took a nap within four hours of learning, while the rest either had no sleep or napped for fewer than 30 minutes. Remarkably, those who took a nap could repeat one-and-a-half tasks on average the following day, in stark contrast to a big zero for the babies who stayed wide awake for the whole afternoon.

“Those who sleep after learning learn well, those not sleeping don’t learn at all,” said Dr Jane Herbert, from the department of psychology at the University of Sheffield.

Previously, it was assumed that staying wide awake is best for learning, yet the findings contradict this. Instead, it seems like learning new things just before a nap is best for infant memory consolidation, according to the paper published in Proceedings of the National Academy of Sciences.

[RELATED] Strikingly similar ape and human infant gestures hint to evolution of language

Dr Herbert added: “Parents get loads of advice, some saying fixed sleep, some flexible, these findings suggest some flexibility would be useful, but they don’t say what parents should do.”

Prof Derk-Jan Dijk, a sleep scientists at the University of Surrey, said: “It may be that sleep is much more important at some ages than others, but that remains to be firmly established.”

In other words, the findings show that sleeping after training renders positive results. Being sleepy during training does not necessarily, though.