Many people think of sleep as a passive, dormant part of our daily lives, and thus if we want to live a vital and productive life we should increase our waking hours and decrease our sleep. Whilst other people, such as busy executives have such a demanding schedule that they have inadequate hours in a day to achieve their goals, and as a consequence their sleep suffers. However, we now know that our brain is very active during sleep, and that different stages of sleep play different roles in maintaining the health of our body.
When we go to sleep we pass through five phases, these include stages 1, 2, 3, 4 and REM or rapid eye movement sleep. The stages progress in a cycle from stage 1 to REM sleep, then the cycle starts over again with stage 1. We spend approximately 20 per cent of our time in REM sleep and the remaining 80 per cent in the other stages. Infants by contrast spend about half of their sleep time in REM sleep. Many sleep researchers believe that REM sleep, which is associated with dreaming, plays an important role in brain development, health and the conversion of short-term memory into long-term memory. The other phases of sleep may play an important role in growth and repair of the body in general.