Theories of sleep

Mind Map by , created over 6 years ago

A-Levels PY4 (Levels of Consciousness) Mind Map on Theories of sleep, created by Hayd23 on 06/16/2013.

Created by Hayd23 over 6 years ago
Aetiologies of Depression
Treatment and Punishment of Crime
PY4 Controversy Definitions
B3, C3, P3
George Moores
Specimen Paper B - Unit 1 – Finance, the Individual and Society (FIS)
Carina Storm
The nature of dreams
Approaches to Profiling
Decision Making of Juries
Theories of Hypnosis
Theories of Crime
Theories of sleep
1 Sleep - a physical and mental resting state where a person becomes inactive and unaware of the environment
2 Restoration theory
2.1 Oswald (1966) believed that the function of sleep was to re-group our resources after expending them during the day
2.1.1 believed that REM was important for brain growth, and SWS was important for bodily growth
2.2 during the first year babies sleep 18/24 hours; age 5 an adult circadian pattern is established, may be due to environmental and maturation factors
2.2.1 newborn infants spend half the 18 hours in REM, adults spend 1/4 of the 18 hours in REM; babies have to grow more
2.3 Sassin (1969) found that when sleep-waking cycles are reversed by 12 hours, the release of GH is also reversed
2.4 also suggested that sleep is an important way of conserving neurotransmitters; through the day, the amount of neurotransmitters in our bodies decreases; REM sleep replenishes neurotransmitters
2.5 Stickgold (2005) - REM important in the consolidation of procedural memory, SWS important for the consolidation of semonic and episodic memory
2.6 Jouvet (1967) - when a cat went into REM sleep it's skeletal muscles relaxed, leading it to fall into the water, waking it up; the more deprived of REM sleep the cat was, the more attempts it made to enter REM; the cat eventually died
2.6.1 REM is necessary for adequate brain functioning
2.6.2 however, cat could've died from stress
2.7 DJ Peter Tripp - stayed awake for 201 hours; started hallucinating and getting paranoid
2.7.1 Randy Gardner - stayed awake for 260 hours; displayed no significant psychotic symptoms however, Randy would've had microsleeps (same as normal sleep)
2.8 Lavie (1984) studied a 20 y.o whose head was injured by shrapnel; no REM and this had no ill effects
3 Evolutionary theory
3.1 Energy conservation
3.1.1 warm-blooded animals need to expend a lot of energy to maintain a constant body temperature
3.1.2 all activities use energy and animals with high metabolic rates use even more
3.1.3 hibernation theory sleep serves a purpose of providing a period of enforced inactivity (using less energy)
3.1.4 however, Capellini (2008) found a negative relationship between metabolic rate and sleep; doesn't support the energy conservation theory
3.2 Predator avoidance
3.2.1 sleep is constrained by predation risk
3.2.2 predators can 'afford' to sleep for longer
3.2.3 prey species must remain vigilant so their sleep time is reduced
3.3 Waste of time
3.3.1 Meddis (1975) - sleep may simply ensure that animals stay still when they have nothing better to do
3.3.2 Siegel (2008) - being awake may be more riskier than sleeping as an animal could get injured

Media attachments