During the day following an all-nighter, or following a deprivation, in relation to our personal needs, of one or two hours of sleep per night for several nights in a row, we can observe various things :
severe irritability
mood disorders
difficulty concentrating for more than 5 minutes
memory loss
a need for constant movement
If sleep deprivation is more severe, the following appear:
hallucinations
less critical thinking and a greater risk of being manipulated
difficulty projecting into the future or making plans
difficulty assessing the long-term consequences of one's actions
Sleep deprivation also has a negative impact on the immune system.
Good to know
Even if an occasional lack of sleep can be made up in a night or two, recovery is not equivalent for the two types of sleep. In fact, our first priority is to make up for our deficit in deep slow wave sleep (physical fatigue), while the deficit in REM sleep (nervous fatigue and memory) will only be made up after physical recovery.
So you need to be particularly vigilant during exam periods! Grab as little sleep as you can, and if you have to, allow yourself enough recovery time to catch up on REM sleep too..
For some, a short nap (15-30 min) can be beneficial.
