Psychology Case

Discuss the restorational theory of sleep? (25 marks)

Oswald (1966) proposed that the purpose of sleep, particularly REM sleep, is to restore the bodily energy reserves, and to repair the state of muscles, as well as the cells and to enable growth to take place. The functioning of sleep is important as it enables the brain neurotransmitters to refill and assist psychological recovery i.e. brain recovery. Sleep consists of two stages the slow wave cycle (SWS) and REM. The main purpose of the SWS is to help the body to repair itself and whereas the REM aids brain recovery.

The Growth hormone is released during SWS. The purpose of the Growth Hormone (GH) is to instigate growth and is considered to have a significant part during childhood. Not only is the GH crucial in childhood but it is also important in adulthood too as it allows protein synthesis and cell growth to occur. This is particularly very important in the restoration of body tissue because proteins are considered to be weak and need to be improved constantly. The constant renewing of the important proteins is an aspect of the recovery process that takes place in the body. The GH is released pulses during the day but large quantities are released during the night especially during the SWS. For example in the Sassin et al study (1969) shows that when the SWS is inverted (when a person goes to asleep in the morning and wakes up at night), the secreted GH is also reversed too. This demonstrates that GH secretion ion controlled by neural mechanisms that are linked to SWS. Other evidence shows that there is a correlation between the quantities of the GH secreted and the amount of SWS (Van Cauter and Plat, 1996), and furthermore the reduction of GH in older age has been associated with reduced SWS (Van Cauter et al., 2000).

A lack of SWS can be linked to reduced work of the immune system which is responsible for the protection against viruses and bacteria that occur in the body (Krueger et al., 1985). This goes on to show that there is a link between viruses and bacteria as the immune system comprises of numerous protein molecules i.e. antibodies which are renewed throughout cell growth and protein synthesis in SWS.

The other stage is called REM sleep which consists of brain growth. REM sleep is more common in infants and considerably higher in premature babies compared to adults. This is caused by babies' rapid brain growth. (Need to elaborate on this).

REM sleep may affect the neurotransmitter activity. Siegel and Rogawski stated that REM sleep enables the neurotransmitter to have a break which allows the neurons to recuperate their sensitivity and permits the body to function adequately.

Psychologists have always demonstrated that there is a link between memory and REM sleep. This was shown in the research by Crick and Mitchison (1983) which illustrated that throughout REM sleep undesirable memories are repressed