purposes of sleep

Question 1

Restoration Theory

Answer 1

proposes that sleep provides ‘time out’ to help us recover from depleting activities during waking time and allows our body and mind to rejuvenate. REM is important for restoring and repairing the mind and NREM sleep is important for restoring and repairing the body.

Question 2

Supportive evidence/ criticisms for the restoration theory

Answer 2

Supportive evidence:
–Infants sleep 16 hours and spend a lot of time in REM as they are consolidating a lot of new memories each day.
–Cognitive declines with sleep deprivation
Criticisms:
•People who are bedridden still experience the same proportions of NREM sleep
•The brain is active still active throughout replenishment. If sleep is restorative, then it is counter intuitive to have the mind be so active during this time

Question 3

The evolutionary Theory

Answer 3

proposes that sleep evolved to enhance chances of survival. The amount of sleep organisms have is determined by how much time it takes them to meet their energy requirements, how easily they can hide from predators and how vulnerable they are to attack.

Question 4

supportive evidence/ critics for the evolutionary theory

Answer 4

Supportive evidence for evolutionary theory:

• Animals such as cows graze, they therefore get little sleep because they need more time to find and consume food
• Animals vulnerable to predators sleep for safety eg- Mice are small so they can hide from their predators easily and can sleep safely for 18 hours

Criticism for evolutionary theory:
•When animals are asleep, they are more vulnerable to predators due to a reduced awareness so it doesn’t make sense that some animals would sleep for so long.
•this theory explains when we sleep not necessarily why we sleep.