Sleep's vital role for memory revealed

Researchers have claimed that infants who nap are better able to apply lessons learned to new skills, while preschoolers are better able to retain learned knowledge after napping.

Rebecca Gomez of the University of Arizona said that sleep plays a crucial role in learning from early in development.

A growing body of research shows how memories become reactivated during sleep, and new work is shedding light on exactly when and how memories get stored and reactivated.

In Gomez's new work, she and he team are examining how young children can recognize instances similar, but not identical, to something they have learned and apply it to a new situation - so-called generalization. Examples in language include the ability to recognize the letter "A" in different types of font, understanding a word regardless of who is speaking it, or recognizing a grammatical pattern in a sentence never before heard.

In one of her new studies, Gomez played an artificial "training language" over loudspeakers to infants 12 months old who were playing. They then tested whether the infants recognized novel vocabulary after either taking a nap or being awake.

To create the artificial languages in her studies, Gomez mimics structure in natural language that may be useful in language learning. For instance, nouns and verbs have subtly different sound patterns in many languages.

Gomez's team is also investigating the role of naps for preschoolers who are learning words. "Infants who nap soon after learning are able to generalize after sleep but not after a similar interval of normal waking time," she says.

"Preschoolers with more mature memory structures do not appear to form generalizations during sleep; however, naps appear to be necessary for retaining a generalization they form before a nap," she added.