Sleep

Babies will sleep for 16-20 hours of the day, and of this 50% will be REM sleep. In premature babies born at 30 weeks the proportions of REM can be up to 80%. At around one years old sleeping patterns are established with 6-8 hours sleep at night and 1-2 hours of sleep in the day. The average time for REM sleep goes down to the average REM sleep for adults at 25%. Between the ages of one and two the adult sleep/wake cycle pattern is established.

Ohayon et al gathered information from 65 studies of sleep from ages 5-102. They found trends in sleeping patterns across ages.

Total sleep time decreased from 470 minuets to 370 at age 70.

The percentage of stage 1 sleep increases from 6% at age 5 to 7% to age 70.

The percentage of stage 3-4 sleep decreases from 24% at age 5 to 9% at age 70.

The percentage of REM also decreases.

Floyd et al also found that REM sleep decreases by 0.6% decay.

There is also a decrease in sleep efficiency as older people have more episodes of walking in the night than the children or younger adults.

Functions of sleep.

Evolutionary explanations. Focuses in ecological niches and how this affects sleep.

Environment- animals have different sleeping patterns because of where they live. Some animals have adapted to sleep in…