Sleep is a diverse, complex, multifaceted series of stages that make important contributions to our daytime functioning. Sleep is induced and maintained by our homeostatic sleep drive, a physiological process that strives to obtain the amount of sleep needed to provide for a stable level of daytime alertness. Wakefulness is induced and maintained by a clock-dependent alerting process, which is controlled by our biological clock.
While there are individual differences, most people need to sleep 8 hours a day. Recent research suggests that ten hours of sleep is required for optimal performance. Energy, vigilance, critical thinking skills, creativity, and ability to effectively process information are all enhanced. Conversely, we accumulate a sleep debt if we do not get adequate amount of sleep consistently. Consider this, going sleepless for a day could affect performance as much as a blood alcohol level above the legal limit. One hour sleep loss every night for an entire week is equivalent of having pulled one all-night.