Feeling Illogical? Take a Nap!

October 16, 2000

Have you ever felt tired before a big test?
Did you stay up late the night before?
Did you feel like taking a nap?

New research suggests that if you had a poor night's sleep, a 15 minute nap after lunch may improve your alertness and logical reasoning.

Scientists at the National Institute of Industrial Health in Kawasaki, Japan, tested 12 students (average age, 22.1 years old) who slept for only 4 hours the night before tests for alertness, memory and logical reasoning. Students were given the opportunity to nap for 15 minutes after lunch (between 12:30 pm and 12:45 pm) and tested several times later in the afternoon.

After only 4 hours of sleep, the students napped for approximately 10 minutes and took only 3.8 minutes to fall asleep. When they awoke from their naps, the students felt less sleepy compared to when they did not nap. When the students were tested at 1:30 pm, they had fewer errors on the logical reasoning test and were more alert compared to when they did not nap. However, memory test scores were only slightly better and were not significantly different after a nap. When tested later in the afternoon, students did not have better scores on any memory or logical reasoning tests after they napped.

These data suggest that a brief nap after only a few hours of sleep the night before may improve alertness and logical reasoning skills. However, the beneficial effects of a nap were seen only in the early afternoon, soon after the nap. Moreover, the experiments studied the effects of naps on a small group of older students. It is unknown if naps will have the same effect on younger students. Previous experiments have shown that naps do NOT improve performance following a night without any sleep. Therefore, naps do not make up for total sleep deprivation, but may help after partial sleep loss. In other words, a nap will not help if you "pull an all-nighter."

WARNING: IF you do take a nap after lunch, make sure you wake up! You don't want to sleep through your class!


Takahashi, M. and Arito, H., Maintenance of alertness and performance by a brief nap after lunch under prior sleep deficit, Sleep, 23:813-819, 2000.

GO TO: Neuroscience In The News Explore the Nervous System Table of Contents

Send E-mail

Fill out survey

Get Newsletter

Search Pages