Recent quotes:

Napping and teenage learning

Routine nappers, who napped five to seven days in a week, had sustained attention, better nonverbal reasoning ability and spatial memory. How long to nap is also an important question? The sweet spot is between 30 to 60 minutes. A nap longer than one hour interferes with circadian rhythm. Participants who slept between 30 to 60 minutes produced better accuracy in attention tasks as well as faster speed. She recommends not to nap after 4 p.m., nor over-nap. Researchers were surprised to find a positive relationship between midday napping and nighttime sleep, which is different than the literature. Habitual nappers (who napped more often) tended to have a better nighttime sleep. “That’s different than the findings in the United States, where napping may serve as a function to replace sleep lost from the previous night. Consequently, that may interfere with the following night’s sleep,” Ji said. “In China, a midday nap is considered a healthy lifestyle. Routine nappers are more likely to experience healthy nighttime sleep. So routine nappers are essentially trained to sleep well and sleep more at night.”

Magical napping

I just want to add that we've done some studies looking at naps in terms of the memory processing and have been rather stunned, really, by the fact that in almost every experiment that we've tried, an hour-and-a-half nap seems to do as much good for memory processing as an entire night of sleep, and we continue to ponder that and sort of conclude that OK, we just don't get it yet. But in studies where six hours of sleep at night seems not enough to lead to consolidation of memory of a particular task, an-hour-and-a-half nap will. So there's something, at least from the memory perspective, rather magical and unusually efficient about napping as opposed to nocturnal sleep.