Question: why do we sleep?????

Blanka Sengerova answered on 26 Jun 2012:

Sleep is important to allow our bodies to regenerate.

I once went to a talk by a sleep researcher and this is how I paraphrased his answer to exactly this question: “Apparently, although only about 50 calories are saved by an average human when sleeping compared to sitting down and resting, sleep is key for enabling brain recovery. This can easily be demonstrated by the problems that arise when lack of sleep is encountered; indeed, Dr Oliver pointed out that in cognitive tests, those who have had no sleep for 17 hours have similar levels of ability as those who have drunk two glasses of wine. And whilst you probably wouldn’t (and certainly shouldn’t) drive after drinking two glasses of wine at the pub, you wouldn’t think twice about doing so when you’ve just done a monster of a day in the office, the lab or the operating theatre from 7am till midnight, yet you might be as likely to cause an accident in the latter as in the former case. In a similar vein, experiments have been carried out to show that sleep helps to consolidate memories acquired during the wakeful hours: when you practice doing a simple task such as tapping out a sequence with your fingers, you get faster and faster at doing it, eventually reaching a plateau where you cannot get any faster. It has been shown that if a night’s sleep follows the learning period, the level of the plateau can be increased.” (The full article is on http://www.scienceoxford.com/news/have-i-got-snooze-for-you-a-review/)