The Restoration Theory Of Sleep

1
Theories of Sleep
Two main theories
1. Restoration theories
2. Ecological theories
http//www.psychology4a.com/biological_rhythms.htm

2
Functions of Sleep Restoration Theory

• BATs
• A01 Describe the restoration approach to the
  functions of sleep
• A02/3 Analyse and evaluate research on the
  restoration approach to functions of sleep
• A02/3 Consider evidence for memory consolidation
  during sleep
• Synoptic points case studies, sleep deprivation
  studies - validity

3
Why do we sleep?

• Jot down 3 reasons why you think we need to sleep

4
The function of sleep is to allow the body to be
repaired/ restored
Did you know? ..Growth Hormone is secreted during
SWS
Van Cauter et al 2000 decline of Growth hormone
in old age associated with reduced SWS
5
Hartmann (1973) said that REM sleep is a time for
making neurotransmitters to compensate for the
amount used during the day.

• Stern and Morgane (1974) also thought that that
  REM sleep allows the brain to restore levels of
  neurotransmitters to 'factory settings'.
• Oswald (1980) claimed that NREM sleep restored
  the body and REM sleep restored the brain,
  through protein synthesis and that Slow Wave
  Sleep (SWS) helped the body restore itself.
• Horne (1988) distinguished between core (SWS
  REM) sleep and optional (stages 1 to 3) sleep

6
Theories of Sleep
Restoration theories
Every stage of sleep is essential for
restoration!
No! Only SWS4 and REM are essential for
restoration!
Horne (1988)
Oswald (1966)

• SWS1-4 are all needed for repair/restoration of
  the body
• REM is essential for repair/restoration of the
  brain

• Core sleep SWS4 REM
• essential for repair/restoration of the brain
• 2. Optional sleep SWS1-3 not needed at all
  for repair/restoration
• Restoration of the body happens
• when we are awake and relaxed

http//www.psychology4a.com/biological_rhythms.htm

7
The main predictions of Restoration Theory are

• Deficits in functioning when sleep deprived
• 'Rebound' effects following sleep deprivation
• Increase in REM sleep during brain growth,
  reorganisation and repair
• Increase in SWS during times of illness or injury

8
Theories of Sleep
Evidence for restoration theories
Total Sleep Deprivation Studies
Partial Sleep Deprivation Studies (REM
deprivation)

• Everson (rats)
• Michel Corke (case study fatal familial
  insomnia)
• Peter Tripp (case study DJ awake 8
  days/nights)

• Jouvet (cats)
• Dement (human REM deprivation)

http//www.psychology4a.com/biological_rhythms.htm

9

• Dement (1960) Effects of REM deprivation were
  severe and included increased aggression and poor
  concentration.
• Randy Gardner, a 17 year old student, stayed
  awake for 11 days (260) in 1965 and effects
  included disorganised speech, blurred vision, and
  a small degree of paranoia.
• DJ Peter Tripp - 1959

• Deficits when sleep deprived?

Stayed awake for 201 hrs in a wakeathon. After
3 days abusive, 5 days began to hallucinate
(spiders in shoes).
10
Rebound effects?

• Dement (1960)
• PPs deprived of REM sleep seemed to have a need
  to catch up Attempts to enter REM sleep doubled
  from an average of 12 to 26 times by the seventh
  night.
• When allowed to sleep normally the participants
  spent much longer than normal in REM sleep, as
  did Randy Gardner.

11
Rebound

• Generally, people catch up on sleep following
  deprivation
• Not all lost sleep is reclaimed
• About 70 of lost SWS and about 50 of lost REM
  typically recovered
• Only some sleep is necessary
• Rebound suggests that sleep is a necessary
  function

psychlotron.org.uk
12
Microsleep

• When participants, being monitored, have been
  sleep deprived for over 72 hours they had short
  periods of MICROSLEEP while apparently awake.
• Williams et al 1959 - EEG recordings show that
  microsleep is the same as sleep

13
Theories of Sleep

• Which of these effects
• could be attributed to
• lack of restoration of the brain?
• lack of restoration of the body?

http//www.psychology4a.com/biological_rhythms.htm

14
Increase in REM sleep during brain growth,
reorganisation and repair?
15
Growth reorganisation

• Reduction in sleep over lifespan
• Highest in infants highest REM in early years
• Some changes in adolescence

5yrs
24 hour period
psychlotron.org.uk
Age
16

• Total sleep time increases during illness
• REM increases during recovery from brain injury,
  ECT drug withdrawal

17
REM sleep and memory

• Crick and Mitchison (1983)
• During REM sleep unwanted memories are disposed
  of thus making more important memories easier
  to access.
• Stickgold, (2005)
• REM may be important to consolidate procedural
  memory (e.g.driving a car)
• SWS important for consolidation of semantic
  memory (knowledge and meaning) and episodic
  memory (events)

18
Over to you

• Read p12-13 and the Restoration Theories of
  sleep worksheet.
• Do the What you need to do activity
• Give one methodological criticism of each study.

19
Evaluation

• The FACE VALIDITY of this theory is high it
  makes sense.
• It is easy to obtain quantitative (OBJECTIVE?)
  data on REM, amount of neurotransmitters etc
• X Extrapolating from hamsters, cats and rats to
  humans is always risky.
• X The research is not always RELIABLE and so we
  might question its VALIDITY. ( human sleep
  deprivation studies and animal sleep deprivation
  studies fatal or not fatal?)
• X Case Studies- 'Alien Among Us' criticism

20
The main problem...

• ...is the lack of death among humans who are
  sleep deprived!!

Rechtschaffen et al 1983 rats died after being
kept wake on a moving disc for 33 days. Stress
more likely the cause!
21
Plenary
Homework q 4 p13

• Do question 3 p13 try this method
• Draw round your hands
• On one hand write the arguments that support
  Restoration Theory
• On the other hand write the arguments against the
  Restoration theory

Against
For