(HealthDay News) -- Babies process and preserve memories during those many naps they take during the day, a new study suggests. "We discovered that sleeping shortly after learning helps infants to retain memories over extended periods of time," said study author Sabine Seehagen, a child and adolescent psychology researcher with Ruhr University Bochum in Germany. "In both of our experiments, only those infants who took an extended nap for at least half an hour within four hours after learning remembered the information." The study doesn't definitively confirm that the naps themselves help the memories stick, but the researchers believe that is happening. "While people might assume that infants learn best when they are wide awake, our findings suggest that the time just before infants go down for sleep can be a particularly valuable learning opportunity," Seehagen said. Scientists have long linked more sleep to better memory, but it's been unclear what happens when babies spend a significant amount of time sleeping. 
 
 In the new study, researchers launched two experiments. In each one, babies aged 6 months or 12 months were taught how to remove mittens from animal puppets. Then some of the babies took a nap for a half-hour and some didn't. A total of 216 babies were tested. 
 
 Then the researchers tested the babies to see if they remembered how to remove the mittens either four or 24 hours later. 
 
 The researchers found that only the babies who'd taken naps after learning actually remembered what they'd learned, especially after 24 hours. 
 
 Study author Seehagen said it's "quite unlikely" that the babies who didn't nap remember less because they were tired. Still, she said more research is needed to confirm the results. 
 
 So, how many naps do babies need and how long should they be? 
 
 "The small number of studies makes it difficult to make firm recommendations to parents," said Angela Lukowski, an assistant professor of psychology and social behavior at the University of California, Irvine. 
 
 However, "the lesson for parents seems to be that napping after learning may help infants remember information over time," she said. She added that naps of at least 30 minutes seem to be helpful, although there hasn't been much, if any, research into shorter naps. 
 
 As for adults, don't worry about napping as a memory aid. "There are many studies in the literature showing the benefit of naps for adults, but adults do not need to nap to retain new memories," said Rebecca Gomez, an associate professor of psychology at the University of Arizona. 
 
 The new study is published in this week's issue of the Proceedings of the National Academy of Sciences. 
 
 More information 
 
 Visit Harvard Medical School's Healthy Sleep website for more about sleep, learning and memory. ||||| Because most babies at those ages are not yet talking, the researchers had to find a nonverbal way to measure how the timing of sleep influenced the strength of a memory. Four furry puppets--two resembling mice and two resembling rabbits, each wearing a detachable felt mitten on one hand--helped researchers infer whether or not a baby had successfully committed his or her experience with the puppets to memory and stored that information for later use. ||||| The potential benefits of infant sleep for memory processing are largely unexplored. Here we show evidence that having an extended nap (≥30 min) within 4 h of learning helps 6- and 12-month-old infants to retain their memories for new behaviors across a 4- and 24-h delay. These results suggest that infants rely on frequent naps for the formation of long-term memories. 
 
 Abstract 
 
 Human infants devote the majority of their time to sleeping. However, very little is known about the role of sleep in early memory processing. Here we test 6- and 12-mo-old infants’ declarative memory for novel actions after a 4-h [Experiment (Exp.) 1] and 24-h delay (Exp. 2). Infants in a nap condition took an extended nap (≥30 min) within 4 h after learning, whereas infants in a no-nap condition did not. A comparison with age-matched control groups revealed that after both delays, only infants who had napped after learning remembered the target actions at the test. Additionally, after the 24-h delay, memory performance of infants in the nap condition was significantly higher than that of infants in the no-nap condition. This is the first experimental evidence to our knowledge for an enhancing role of sleep in the consolidation of declarative memories in the first year of life.
– It's long been thought that napping is an important part of a baby's growth—both physically and mentally. Now new research in the Proceedings of the National Academy of Sciences suggests that naps help babies form new memories, and that when a nap directly follows a new activity the baby is far likelier to recall it the next day than if that child doesn't nap until four hours after the activity, reports the Los Angeles Times. "In both of our experiments, only those infants who took an extended nap for at least half an hour within four hours after learning remembered the information," the study's lead author tells HealthDay News. To test a baby's recall, researchers studied 216 babies ages 6 months and 12 months. They demonstrated how to remove mittens from animal puppets, and found that those who then took naps at least 30 minutes long (and typically more like 80) were better able to recall how to remove the mittens 24 hours later than those who didn't nap until four hours later. Whether a baby napped just before the experiment made no difference. The authors also hypothesize that because the hippocampal region—key to memory formation—is so small in babies, it may only be able to store smaller chunks of information, hence the need for frequent sleep early in life. (Other research shows a newborn's brain grows 1% a day.)