Individual (Sleep + Dreams)

Question 1

Date and describe Oswald’s theory of sleep.

Answer 1

Oswald (66) Restoration theory:

• During sleep the body carries out repairs on the brain and body
• Explains why all complex animals require sleep
• If sleep was not necessary animals would have evolved out of the behaviour as it makes them vulnerable
• Physical repairs i.e. repair of minor injuries, removal of waste chemicals, replenishment of neurotransmitters and restoration of energy levels
• REM sleep = biological repairs
• Non-REM = restoration of brain processes via protein synthesis
• Shapiro (81) supports this finding that runners sleep for 90minutes longer after an ultra-marathon. REM sleep increased from 25% to 45% of total sleep
• Animal studies also show that sleep derivation deteriorates biological functioning

Question 2

Date and describe Crick and Mitchison’s theory of sleep and dreams.

Answer 2

Crick and Mitchison (83) Reorganisation theory:

• Proposal that during REM sleep a reverse-learning process takes place
• The brain carries out a “decluttering” process
• Unnecessary information is discarded in order to make space and increase efficiency in the brain
• Dreaming is a visual representation of this sorting process
• This explains why dream content often cant be recalled the following day; as the information is no longer there
• This also explains why dreams may be recalled better if the individual is woken up during the dream; because the information has not yet been properly sorted
• Certain species of dolphins that don’t dream have large brains. In theory this could be because their brain does not undergo the “pruning” process during sleep

Question 3

Evaluate Oswald’s theory of restoration (1966)

Answer 3

Restoration theory (1966)

Pro’s

• Supported by Shapiro et al (1981)
• Explains why there is loss of consciousness

Con’s

• Some psychologists argue that sleep is not purely for restoration and other processes are necessary for restorations to occur
• It can be argued that it sleep is not essential for sleep; Horne showed in a study that it was the warmth generated from exercise that increased sleep time rather than bodily repairs

Question 4

Name and date two significant studies on sleep and dreams.

Answer 4

Sleep and dream studies:

• Dement and Kleitman (57) study of REM sleep
• Czeisler et al (90) Study of synthetic lighting

Question 5

Date and describe Dement and Kleitman’s key study of sleep and dreams.

Answer 5

Dement and Kleitman (1957) study of REM sleep

Aim: To find a link between sleep stages and dreaming

Method:
- 9 adults (7 male, 2 female)

• Tested in a sleep laboratory
• Participants were told to avoid alcohol and caffeine
• Participants were woken several times during the night and questioned on if they had been dreaming, and if so, what about and how long for.

Findings:
- Participants were more likely to state they had been dreaming when woken during REM (80%)

• Eye movements appeared to match descriptions of dream content e.g. one participant said they had been dreaming about people throwing tomatoes at each other and they eye movement was horizontal left-to-right

Question 6

State two advantages and two disadvantages of Dement and Kleitman’s (1957) study of sleep and dreams

Answer 6

Evaluation of Dement and Kleitman:

Con’s
- Artificial setting may lead to unnatural behaviour, this makes results less ecologically valid

• The sample size was small and only had 2 women, meaning results are not representative and could be biased towards the dream behaviour of men

Pro’s
- High level pf control, allowing the experimenters to reduce the impact of extraneous variables

Question 7

Name and describe a sleep study other than Dement and Kleitman (1957)

Answer 7

Czeisler et al (1990) Exposure to light and shift work

Aim: To find out if disturbances in the sleep-wake cycle created by shift work can be treated with timed light exposure

Method:
- 10x 2 week studies

• 8 male participants split into two groups
• The control group received no light treatment (150 lux light for nightshift and daylight during their time off)
• The experimental group were given 7000 lux light during their nightshift and kept in complete darkness during their time off
• This was controlled in a sleep lab

Results:
- The experimental group reported increased alertness while on shift and showed an enhanced cognitive performance, suggesting the treatment had helped them to adapt to the shift work

Question 8

Give one strength and one weakness of the Czeisler et al (1990) study

Answer 8

Evaluation of Czeisler et al:

Pro
- The laboratory conditions allowed precise control over lighting meaning all experimental participants were given the exact same treatment. This helps to increases the reliability of the study

Con
- A very small sample size was used, making results hard to generalise.

• Only males were used meaning results cannot necessarily be applied to women

Question 9

What is sleep?

Answer 9

Sleep:

• An altered state in which consciousness is temporarily lost and the CNS becomes inactive

Question 10

What are circadian rhythms?

Answer 10

Circadian rhythms:

• Also known as the “body clock”
• The 24hr cycle which tells the body when to wakeup, eat, sleep etc.
• An example of circadian rhythms is the sleep/wake cycle
• The body uses environmental cues in order to regulate this cycle, for example sunlight and temperature

Question 11

Describe sleep stages 1-3

Answer 11

Sleep stages:

Stage 1

• Light sleep
• Easily woken
• Still responsive to external environment

Stage 2

• Occurs 10 mins in
• Sound asleep
• If woken may not be aware sleep has occurred
• Sleep spindles show on EEG

Stage 3

• Occurs 25 mins in
• Unresponsive to surroundings
• Difficult to wake up
• Delta waves show on EEG

Question 12

Describe sleep stages 4 and REM

Answer 12

Sleep stages:

Stage 4

• Progression from stage 3
• Sleep becomes gradually deeper after 25 minutes
• Delta-waves occur more and more frequently on EEG
• Subject is deep in sleep and cannot be woken easily

REM sleep

• Occurs after 90mins
• Eye movement occurs
• Body is temporarily paralysed
• EEG pattern becomes mixed
• Dreams occur

Question 13

What are three common symptoms of sleep deprivation?

Answer 13

Symptoms of sleep deprivation:

• Lowered mental performance (memory, attention, concentration etc.)
• Visual hallucination, disorientation, paranoia
• Mood changes
• The study of radio DJ Peter Tripp, who stayed awake for 200hrs demonstrates many of these unpleasant symptoms

Question 14

State three factors that can affect sleep

Answer 14

Factors affecting sleep:

• Drugs
  (Stimulants e.g. caffeine and amphetamines + alcohol can change proportion of REM sleep)

Zeitgebers
(Light and darkness can change hormones associated with sleep in the brain i.e. melatonin)

Noise

Anxiety
(Stress and anxiety related mood disorders have been shown to affect ability to sleep)

Question 15

How does the biological approach explain sleep?

Answer 15

Biological approach (sleep)

The biological approach explains behaviour in terms of physiology and genetics

• A brain area known as the SCN, within the hypothalamus, is the region associated with control of circadian rhythms and is sensitive to light
• The SCN releases the hormone melatonin, triggered by the absence of light
• A chemical by-product called adenosine builds up in neurons. This is cleared during sleep and replaced with glycogen which provides energy

Question 16

How does the biological approach explain dreams?

Answer 16

Biological approach (dreams)

• Dreams are caused by random brain activity
• Biological theory suggests that random neural firing from the pons sends messages to the neocortex and here the brain tries to make sense of the signals, displaying them as dreams
• A criticism of this theory is that it cannot explain why 70% of dreams make sense

Question 17

How does the cognitive approach explain sleep?

Answer 17

Cognitive approach (sleep)

Cognitive approach explains behaviour in terms of mental processing based on models like the computer analogy and schemas.

• Sleep aids the brain in processing information
• During sleep the brain cleans up unneeded files, allowing the brain to run more efficiently and strengthen memories
• This is supported by Crick and Mitchison’s reorganisational theory (1983)

Question 18

How does the cognitive approach explain dreams?

Answer 18

Cognitive approach (dreams)

• Dreaming is what the brain does when its not focussed on any other specific tasks to carry out
• This explains why daydreams occur in a similar way; as they also occur when the brain is not focussing on other things
• Dreaming is continued mental processing, built from daytime schemas
• This explains why dream content often makes sense and why content is sometimes related to what we have been thinking about during the day, however, the approach doesn’t explain why this is not always the case

Question 19

How does the psychoanalytic approach explain sleep?

Answer 19

Psychoanalytic approach (sleep)

The psychoanalytic approach explains behaviour in terms of the relationship between the conscious and the unconscious mind. This approach looks at the id, ego and superego and the stages of sexual maturity.

• Freud believed sleep is motivated process which allowed the mind to withdraw from the external world, allowing it to be in a care-free state

Question 20

How does the psychodynamic approach explain dreams?

Answer 20

Psychodynamic approach (dreams)

• Freud believed during sleep the id becomes dominant and unconscious desires are free to be presented to the mind in the form of dreams i.e. we dream about what we really want
• Freud also believed that the true meaning of dreams can be hidden, particularly if the message is disturbing or embarrassing
• Dreams contain symbols (manifest content) which can be interpreted to reveal the true meaning (latent content)
• For example, Little Hans dreamed about his penis during the phallic stage

Question 21

Describe Freud’s case study of Little Hans

Answer 21

Little Hans - Sigmund Freud

Aim: To find evidence to support the Oedipus complex (idea that sons have rivalry with father over the mother)

Method:

• Freud exchanged letters with the father of little Hans
• Discussed the behaviour of Hans, mainly his phobia of horses

Findings:
- Hans was frightened of horses after seeing one collapse in the street

• Hans also worried about the birth of his younger sister and associated this with a horse and cart
• Hans dreamed about being married to his mother, about a crumpled giraffe being squashed by a big giraffe and about a plumber who removed his penis and replaced it with a larger one

Question 22

Name and describe two sleep disorders

Answer 22

Sleep disorders:

Insomnia

• Inability to get to sleep
• Trouble staying asleep
• More common as people age
• Can cause tiredness and problems functioning during the day

Circadian rhythm sleep disorders (CRSD)

• This is when the individuals circadian rhythms are not synchronised with the normal sleep/wake cycle. Can include:
• Going to sleep earlier/later each night
• Waking up and going to sleep at variable times
• Regular rhythm which is not set to the normal 24hr schedule

Sleep apnoea

• The individual stops breathing for a few seconds during sleep
• The body detects the lack of oxygen and wakes the individual up, although they may not recall it as its brief
• Leads to poor sleep quality
• Can reduce alertness during waking hours