The effects of lunch time napping on habitual nappers’ mental work efficiency in the afternoon and early

30 college students who have the habit of lunch time napping (LTN) participated in experiments under two different conditions: Having lunch time napping and not having lunch time napping. They were asked to complete three tasks including vigilance reaction, short-term memory, addition arithmetic; their performance was recorded automatically by computer during 3 different periods in the afternoon and early evening. The analysis about the experimental data showed that: as for habitual nappers, midafternoon nap zone existed, LTN played a very important role in overcoming it, and did great help in enhancing their vigilance in the afternoon and early evening, however, LTN didn’t bring significant positive effect to executing complex tasks (such as short-term memory and addition task) at the periods of time 16:30-17:30, 20:0021:00. Finally, this article discussed the conclusions and its significance.