Individual (Sleep + Dreams)

Question 1

What is sleep?

Answer 1

Sleep is an altered state in which consciousness is temporarily lost and the CNS becomes inactive.

We spend about a quarter of our lives asleep.

Sleep hormone (melatonin) is also released in animals when it gets dark.

Our sleep cycles reflect modern lighting.

Question 2

What is “Polyphasic Sleep”?

Answer 2

Polyphasic sleep literally means many (poly) stages (phasic) of sleep. So in the UK, we sleep for blocks of time. In other areas like Spain, it is normal for people to have a shorter sleep or a “Siesta”. This type of sleep is called polyphasic sleep. However this type of sleep schedule does not suit shift work.

Question 3

What are circadian rhythms?

Answer 3

Circadian rhythms (also known as the “internal body clock”):

• Circadian rhythms are controlled by the hypothalamus, more specifically, a part is known as the super chiasmic nucleus (SCN).
• The SCN gets info about light levels from nerves in the eye.
• The SCN controls the production of melatonin.
• The 24-hour cycle tells the body when to wake up and sleep along with many other bodily functions.
• 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 4

What is the role of the SCN in sleep?

Answer 4

The SCN controls the production and release of melatonin.

Melatonin gets released when it gets dark.

Causes drowsiness and feelings of tiredness.

It peaks in the middle of the night.

And it decreases during the daytime.

Question 5

What is the role of adenosine in sleep?

Answer 5

Adenosine:

• Builds up during the day.
• Causes you to get gradually more tired throughout the day.
• When we go to sleep, the build-up is cleared.
• The adenosine gets replaced by energy.

Question 6

How does caffeine affect sleep?

Answer 6

Caffeine:

• Caffeine blocks adenosine receptors.
• Body is less receptive to adenosine due to desensitization.
• Reduced feelings of tiredness.

Question 7

Describe sleep stages 1-3

Answer 7

Sleep stages:

Stage 1:

• Lasts for 10 mins.
• Light sleep.
• Easily woken.
• Still responsive to the external environment.

Stage 2:

• Lasts for 15 mins.
• Sound asleep.
• If woken may not be aware sleep has occurred.
• Sleep spindles show on EEG.

Stage 3:

• Lasts for 20 mins.
• Unresponsive to surroundings.
• Difficult to wake up.
• Delta waves show on EEG.

Question 8

Describe sleep stages 4 and REM

Answer 8

Sleep stages:

Stage 4:

• Lasts for 45 mins.
• Delta waves occur more and more frequently on EEG.
• Subject is deep in sleep and cannot be woken easily.

REM sleep

• Lasts for 25 mins.
• Eye movement occurs.
• Body is temporarily paralyzed.
• EEG pattern becomes mixed.
• Dreams occur.

Question 9

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

Answer 9

Dement and Kleitman’s (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 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%). And if woken during any other stage, only 9% reported dreaming.

• 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 their eye movement was horizontal left-to-right.

Question 10

Explain the role of zeitgebers in sleep.

Answer 10

Zeitgebers are also known as external cues.

Zeitgeber is a German word that literally ‘time giver’.

The SCN can (to an extent) keep track without external cues.

Its own exogenous cues can maintain a schedule when traveling in different time zones.

Light & Dark are important zeitgebers from evolution.

Artificial light can affect our sleep.

Question 11

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

Answer 11

Evaluation of Dement and Kleitman:

Cons:
- Artificial settings may lead to unnatural behavior, 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 toward the dreaming behavior of men.

Pros:
- High-level control, allowing the experimenters to reduce the impact of extraneous variables.

Question 12

What french researcher tested their internal body clock to an extreme?

Answer 12

Michel Siffre:

Slept in a cave in total darkness for three months with no natural light.

NSA monitored his SCN and found it mainly kept to a 24-hour cycle but shifted by a few minutes.

However, his ability to keep track of time was impaired. So although he went in for 3months, he came out thinking he had only spent 2 months in the cave.

Question 13

How much sleep do people need?

Answer 13

This varies.

• Adults need 7-8 hours.
• Babies and young children need more sleep.
• Amount of sleep needed reduces in your lifetime.
• A few people can function on 6 hours of sleep but that can cause sleep dept.
• In adolescence sleep clock shifts gradually later.

Question 14

What are some individual differences in circadian rhythms?

Answer 14

Larks vs Night Owls.

• Some people are prone to early wakening (Larks).
• Others stay up late and get up late (Night Owls).
• Differences are mainly genetic.
• Only around 25% are true night owls.
• Owls are better at logical tasks in the evening, and creative tasks in the morning.

Question 15

What is the impact of sleep on young teenagers? Who studied this and in what year?

Answer 15

Teenagers and Sleep, studied by Wolfson and Clarkson (1998).

They studied 3000 teenagers.

Grades were affected by the amount of sleep they were getting (more sleep = better grades)

Sleep consolidates learning.

The average sleep time was 7 hours 20 minutes.

However, they did not study them long-term so we cannot conclude about the long-term effects of sleep.

Question 16

Date and describe Oswald’s theory of sleep.

Answer 16

Oswald (1966) 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 behavior 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 (1981) 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 deprivation deteriorates biological functioning.

Question 17

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

Answer 17

Crick and Mitchison (1983) 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 18

Evaluate Oswald’s theory of restoration (1966)

Answer 18

Restoration theory (1966).

Pros:

• 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 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 19

Name and date two significant studies on sleep and dreams.

Answer 19

Sleep and dream studies:

• Dement and Kleitman’s (1957) study of REM sleep.
• Czeisler et al (1990) Study of synthetic lighting.

Question 20

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

Answer 20

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 were 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 was given 7000 lux light during the night shift 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 21

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

Answer 21

Evaluation of Czeisler et al:

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

Cons:
- A very small sample size was used, making results hard to generalize.

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

Question 22

What are three common symptoms of sleep deprivation?

Answer 22

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 23

State three factors that can affect sleep

Answer 23

Factors affecting sleep:

Drugs (Stimulants e.g. caffeine and amphetamines + alcohol can change the 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 the ability to sleep).

Question 24

How does the biological approach explain sleep?

Answer 24

Biological approach (sleep).

The biological approach explains behavior in terms of physiology and genetics

• A brain area known as the SCN, within the hypothalamus, is the region associated with the 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 25

How does the biological approach explain dreams?

Answer 25

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 26

How does the cognitive approach explain sleep?

Answer 26

Cognitive approach (sleep).

The cognitive approach explains behavior 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 reorganizational theory (1983).

Question 27

How does the cognitive approach explain dreams?

Answer 27

Cognitive approach (dreams).

• Dreaming is what the brain does when it’s not focused 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 28

How does the psychoanalytic approach explain sleep?

Answer 28

Psychoanalytic approach (sleep).

The psychoanalytic approach explains behavior 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 to process that allowed the mind to withdraw from the external world, allowing it to be in a care-free state.

Question 29

How does the psychodynamic approach explain dreams?

Answer 29

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) that can be interpreted to reveal the true meaning (latent content).
• For example, Little Hans dreamed about his penis during the phallic stage.

Question 30

Describe Freud’s case study of Little Hans

Answer 30

Little Hans - Sigmund Freud.

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

Method:

• Freud exchanged letters with the father of little Hans.
• Discussed the behavior 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 31

Name and describe two sleep disorders

Answer 31

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.

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.

Question 32

What are some factors that affect sleep quality?

Answer 32

Factors that affect sleep quality:

Drugs:

• Caffeine takes 5 hours for it to drop effects by half.
• Nicotine & illegal drugs