Losing sleep over sleep deprivation? On average, Americans live for approximately 75 years, of which they spend about 25 years sleeping. There is perhaps no other single activity that preoccupies a human life as much as sleep does.
Sleep is a universal trait in the animal kingdom and is likely an evolutionary survival tool. It is speculated that sleep offers adaptive inactivity to ensure that species are not active and exposed to predators when they are most vulnerable. Other theories include energy conservation theory, restorative theory (time for the brain to repair itself) and brain plasticity theory (sleep correlated to bodily changes such as growing children needing more sleep than grown adults). Although there is no consistent empirical data to pin any of these theories to the evolutionary purpose of sleep, biological truth about the purpose of sleep is likely hidden among all of these theories. What we do know, is that sleep is not, however, a state of unconsciousness as envisioned in the early days, but is a highly metabolically active state.Read More