subject: Why Is Sleep Essential? [print this page] After years of study scientists still have not been able to discern the specific reason why humans need sleep, yet from birth human beings spend a third of life asleep. It is only known that after 15-17 hours the body becomes tired and demands around 7 "" 9 hours sleep.
Beside the functions of cell re-generation and detoxification, the predominant theory is still, the brain demands sleep and that memory consolidation may be just one its functions.
A noted sleep researcher at Madison's University of Wisconsin, Guilio Tononi, has devised a different theory. He thinks that the sleeping brain appears to get rid of redundant, or unwanted, synapses, or connections. Tononi states this permits a person to remember what is important and forget what not relevant.
"We think what's happening during sleep is that you open the aperture of memory and are able to see the bigger picture," says senior author, Matthew Walker, a neuroscientist at the University of California. He believes people figure out what they didn't truly understand when awake, "Only when you enter this wonder-world of sleep do these insights occur."
Scientists know that sleep loss makes a person more emotionally fragile, more irresponsible, less able to focus and almost certainly more open to infection. Laboratory experiments with animals confirm that a total lack of sleep leads to death.
While these figures appear to increase with age, the average duration of sleep requirements seems to be 7.58 hours for men and 7.12 hours for women.
Study results from two continents, over twenty years, contradict the widely-held hypothesis that it is beneficial to rest for a minimum of 8 hours each night. The researchers have concluded that those who sleep 8 hours or longer have a higher mortality risk than those who sleep around only 7 hours.
While the reason for this is still unidentified, not only do humans need sleep, but all mammals and birds sleep. Fish, reptiles and insects all experience some kind of rest.
