Study: Newborns Learn During Sleep

(May 19) -- Newborn babies spend most of their time sleeping, but new research suggests that these infants are taking advantage of the nap time by learning while they nod off.

A research team at the University of Florida evaluated 26 1- to 2-day-old newborns as they slept. Unlike adults, whose brains stop displaying signs of learning during sleep, the babies exhibited brain waves that indicated ongoing engagement with the physical world.

As the babies slept, researchers played an auditory tone, alternated with a gentle puff of air to the eyelids of each baby.

After 20 minutes, the babies could anticipate the puff of air and would clench their eyelids in anticipation after hearing the tone. To the team, the reaction indicates that the infants had quickly learned to associate the tone with the puff of air.

Meanwhile, the babies' brain waves would change to correspond to the expectation.

"They are better learners, better 'data sponges' than we knew," said psychologist Dana Byrd, who led the study published in this week's Proceedings of the National Academy of Sciences. "Newborn infants' sleep patterns are quite different to those of older children or adults in that they show more active sleep where heart and breathing rates are very changeable."

The study has implications for the healthy development of infants. It could be used to pinpoint those whose cognitive progress is hampered, such as those with dyslexia or autism.

It might also be a way to assess risk factors for sudden infant death syndrome, or SIDS, because sleep disturbances are thought to be implicated in the deadly condition.

"It [involves] the same brain circuits implied to be abnormal in some of these disorders," Dr. William Fifer, a co-author of the study, told MedPage Today. "This could help us in understanding some of the early patterns of brain activity and maturation that may be relevant for those disorders."

The researchers caution that babies can't absorb just anything during their resting hours. Rather, the infants exhibited the ability to learn conditioned responses during sleep, so this "isn't the kind of learning that has to do with exposure to [or interaction with] some event," Fifer said.