hi this is gladmohesh .manipalite ,now in chennai as lecturere.will tell u something that i have observed.first usually students will sleep in the afternoon classes.maybe they need rest after a lunch.i feel that excess o2 is needed for the git after alunch to digest and assimilate the things eaten.second early morning classes they go for a deep sleep .mayb bcoz the previos night they didnt have better sleep and so after a cold water bath they feel sleepy .as body takes time to rejuvenate the energy lost.third ,of the most important i have experienced is if the class room was locked up the night with no air circulation and the next day mornign when 50 -100 students sit together and take all the o2 available co2 build up and so i think most of te students go for a nap even with eyes wide open.above all 4th is that when the physiology lec r prof goes for a continous lec for more than 3o mins without the student understanding what he wanted to know fatigue sets in and he finds the profs lec as a lullaby adn goes for a fine nap.

One reason could be that the students are overworking and not sleeping well before the day of the exam.

why do students feel highly sleep during Exam compare to normal sleep ?
please consider this concept on basiced on physiological and neurological
points...............i m v.sure u will consider my concept..i m waiting for your response for this.thanking u all.