Abstract
The effects of 3-h nap in the early morning on performance and sleepiness during prolonged continuous works were studied. After one night sleep recording, subjects performed prolonged works for 20 hours. Following the 20 hours of works, four subjects took a 3-h nap lying in a bed (0400-0700), and the other four subjects took a 3-h rest sitting in a reclining chair. After taking a 3-h nap or rest, they performed the same works again for 12 hours. In working period, three different computer tasks were administered every 15 min. Results revealed that the early morning nap had a positive effect upon the improvement of performance and sleepiness, lasting 2 to 3 hours following the nap, and it delayed the decline in performance and the increase of sleepiness for several hours.
