Naps play a significant role in the development of infants' brain, helping them retain new information, researchers have observed.
Experts at the University of Arizona in Tucson found differences between babies who were able to get in a little daytime nap and those who did not.
Rebecca Gomez, Richard Bootzin and Lynn Nadel in the psychology department at the university discovered that those had napped were more likely to show an advanced level of learning known as abstraction.
Nadel said: "It's a fairly nuanced story. What we know is that infants have mostly REM sleep, given the type of sleep they have, given how their brains are developed at that point. And they have to get some of that sleep within a reasonable amount of time after inputting information in order to be able to do abstracting work on it.
"If they don't sleep within four to eight hours, they probably just lose the entire thing."
Nadel, a Regents' Professor at the UA, was due to explain the group's work (Early Learning in Infants May Depend on Sleep) in a session at the American Association for the Advancement of Science annual meeting in San Diego. (ANI)