Sleep And Dreams

Question 1

Suprachiasmatic nucleus (7)

Answer 1

• controls circadian rhythms
• area of the hypothalamus
• gets information from nerve cells in the eyes about whether it is light or dark, allowing the brain to know when it’s time to sleep.
• controls the release of melatonin, a hormone which makes us feel sleepy
• SCN sends a message to the pineal gland and this gland releases the hormone
• released in bloodstream usually in the evening
• melatonin levels peak in the middle of the night and then start to fall back down to daytime levels

Question 2

What are circadian rhythms? (4)

Answer 2

• the body’s natural processes that vary over a 24 hour cycle.
• sleep/wake cycle
• when it’s dark we start to feel tired and when it gets light again we wake up
• internal body clock

Question 3

What is the role of the brain in sleep? (5)

Answer 3

• SCN triggers the release of melatonin when it receives information that it is getting dark
• SCN controls our internal (endogenous) body clock causing us to maintain circadian rhythms on a 24 hour cycle
• adenosine builds up in our neurons because of the brain’s daily activities making us feel tired later on in the day
• brain cycles through REM and non-REM sleep. Non-REM sleep divided into stages. Delta waves found in stages 3 and 4 which can be measured using an EEG brain scan.
• sleep helps the brain to stay healthy and consolidate new memories which have been learned

Question 4

REM and non-REM sleep (3)

Answer 4

• five sleep stages
• change from one stage to the next can be observed by the size and speed of electrical brainwaves that show up on the EEG
• REM sleep is when the brain becomes much more active when we dream. Body is temporarily paralysed and eyes move from side to side.

Question 5

How do drugs affect sleep? (4)

Answer 5

• stimulant drugs make people more alert, keeping them awake and reducing their quality of sleep e.g. caffeine, amphetamine
• caffeine blocks adenosine receptors in the neurons making you feel less tired
• alcohol can affect sleep by making people more sleepy. Alcohol also changes proportion of REM and non-REM sleep
• prescription drugs can interfere with sleep patterns

Question 6

How does light affect sleep? (3)

Answer 6

• artificial light and screens can affect the release of melatonin (blue)
• can act as zeitgebers meaning the SCN might fail to keep track of when it is night and day
• could argue some studies show that blue light doesn’t have the same effects on the younger generation compared to the older generation because they grew up without screens

Question 7

Aim of Dement and Kleitman (1957) study of REM sleep (1)

Answer 7

• to find the link between dreams and sleep stages. Find out the function of REM sleep and whether eye movements during REM sleep were connected to the content of dreams

Question 8

Hypothesis of Dement and Kleitman (1957) study of REM sleep (1)

Answer 8

• that there would be a relationship between REM sleep and dreaming. Content of the dream would link to eye movement patterns. Duration of eye movement would be the same as the reported duration of the dream. Participants will more often recall dreaming when woken up in REM sleep compared to non-REM sleep.

Question 9

Method of Dement and Kleitman (1957) study of REM sleep (5)

Answer 9

• 9 adult participants (seven males, two females)
• observed sleeping over a number of night in a laboratory
• woken during sleep
• EEG measurements recorded brain activity and eye movement
• participants told to avoid alcohol and caffeine during the day

Question 10

Results of Dement and Kleitman (1957) study of REM sleep (4)

Answer 10

• when woken in REM sleep, 80% of the time participants a reported a clear dream
• participants generally couldn’t recall any clear dreams when woken in non-REM sleep
• eye movement was linked to the eye of dream a participant had
• duration of REM sleep showed a relationship with the length of the dream recalled

Question 11

Conclusion of Dement and Kleitman (1957) study of REM sleep (1)

Answer 11

• dreams recalled more often when woken in REM sleep compared to non-REM sleep

Question 12

Evaluation of Dement and Kleitman (1957) study of REM sleep (7)

Answer 12

• study established REM study as the time for dreaming
• participants weren’t told what stage of sleep they were in when they were woken
• sample size very small
• gender bias
• so children included
• participants slept with EEG cap on with wired and sensors which doesn’t reflect someone’s typical nights sleep
• don’t know for sure whether participants didn’t consume alcohol or caffeine

Question 13

Aim of Czeisler study (1990) study of shift workers (1)

Answer 13

• to see if exposing participants to bright light would help night shift workers fully adapt to daytime sleeping. To see if the circadian rhythms could be regulated and and the SCN can be reset by up to 12 hours.

Question 14

Hypothesis of Czeisler (1990) study of shift workers (1)

Answer 14

• that exposure to bright light during the night and darkness during the day would help participants to feel awake at night and then tired during the day

Question 15

Method of Czeisler study (1990) study of night shift workers (4)

Answer 15

• 2 weeks long
• 8 men between the ages of 22 and 29
• told not to take drugs or alcohol
• exposed to very bright light while working

Question 16

Results of Czeisler study (1990) study of shift workers (3)

Answer 16

• participants exposed to bright light during their night shifts and then darkness during the day slept for 2 hours more than the control group
• control group’s temperatures dropped during the night
• treatment group’s temperatures fell in the middle of the day

Question 17

Conclusion of Czeisler study (1990) study of shift workers (4)

Answer 17

• participants able to adapt to working at night
• got more worker done it was safer
• circadian rhythms can be shifted
• concentration, alertness, cognitive performance improved

Question 18

Evaluation of Czeisler study (1990) study of night shift workers (4)

Answer 18

• took into account people will be exposed to natural light on their way home from work
• small sample size of 8 and they were all men
• many variables not controlled such as drugs, alcohol, when the participants ate breakfast, if the participants actually stayed in the dark when they got home
• showed us about eh effect of night working and the damage it can do mentally and physically

Question 19

What is the restoration theory? (5)

Answer 19

• Adam and Oswald 1983 - sleep is needed to help with the restoration of the brain and body
• brain restoration happens in REM sleep and bodily restoration happens in non-REM sleep
• brain is restored by giving it a rest
• supplies of neurotransmitters and brain proteins restored
• bodily restoration - repairing minor injuries like skin, muscles, and removal of waste chemicals in the muscles

Question 20

Evaluation of the restoration theory (7)

Answer 20

• studies show when an animal is deprived of sleep their biological functions deteriorates
• new born babies have higher proportion of REM sleep which means lots of brains growth
• periods of REM sleep increase if someone is sleep deprived or has been doing lots of physical activity
• counter argument - evolutionary theory states sleep to survive, avoid predators, and to save energy
• don’t know for certain if more REM sleep after a brain injury is because of the restoration process
• Horne (1978) - sleep deprivation didn’t have affect on participants ability to perform physical exercise
• sleep deprivation affects immune system

Question 21

Information processing (5)

Answer 21

• function of sleep is to process information which has been learnt throughout the day
• hippocampus involved in processing memories especially long term memories
• when you sleep you develop a schema for something you have just learnt about
• during sleep memories that were in your short term memory in the hippocampus transfer to the neocortex where long term memories are stored
• sleep deprivation studies show that someone who is sleep deprived is less able to remember information

Question 22

What is the reorganisational theory? (4)

Answer 22

• we dream to get rid of memories that aren’t useful to us anymore
• room is made in our brain for new memories to be made as our brain’s storage capacity is limited
• reverse learning - learning done while awake forming memories is undone when we dream
• adaptive memories are useful and parasitic memories are useless/harmful.

Question 23

Evaluation of the reorganisational theory (4)

Answer 23

• shows the importance of REM sleep - leaves space in our brains for new memories to be made
• aligns with biological evidence such as the activation synthesis theory
• based on computers not people
• doesn’t explain how are dreams often follow a story and aren’t just a random collection of thoughts

Question 24

Analysis of the reorganisational theory (6)

Answer 24

• link between reorganisational and restoration theory. They both agree that dreams are a byproduct of brain activity. However they also disagree as they both argue different things. (2 points)
• application - learning a new skill which is consolidated after a nap
• studies show that 90 minute naps can be just as beneficial as a full nights sleep
• studies show that babies learning new skill recall it better after a nap
• Walker et al. (2003) conducted a study involving a finger tapping task to study the role of sleep in learning new memories
• showed that recalling something the next day helps the memory to be reactivated

Question 25

Cognitive process evaluation (4)

Answer 25

• mostly uses laboratory experiments which makes it scientific
• have given us treatments for sleep disorders such as insomnia
• ignores other influences on behaviour e.g. hormonal influences
• laboratories aren’t a natural environment for sleeping

Question 26

Conscious and unconscious processes (5)

Answer 26

• the id is your unconscious mind and becomes dominant when you sleep and is the main motivation of pleasure
• the ego is your conscious mind and controls all our thoughts, memories we are aware of in the given moment
• memory is not always part of our consciousness but can be accessed at any time so we can become aware of it
• unconscious mind contains memories, thoughts, and feelings that we aren’t aware of. Contains stuff that has been pushes away because it is too unbearable. Influences how be act even though we are unaware
• the superego is the unconscious cultural rules that people internalise

Question 27

Manifest and latent content (4)

Answer 27

• manifest content is what the dream appears to be about
• latent content is what the dream is really about
• e.g. dream about school, hidden meaning fear of being judged
• true desires hidden behind symbols to protect the dreamer from anxiety

Question 28

What is the psychodynamic approach? (3)

Answer 28

• when we dream we dream in symbols and those symbols represent the dream’s true meaning
• the true meaning of a dream is often too harmful for someone to process which is why the dreams appear in symbols
• id, ego, and superego (3 points)

Question 29

Evaluation of the psychodynamic approach? (4)

Answer 29

• helped to shift people’s view on whether dreams predicted the future as it showed that that wasn’t true
• given an explanation for many phobias
• most experts disagree with this theory and it is only taught as what people used to think
• doesn’t explain why people get nightmares because those thoughts are supposed to be too harmful to think about

Question 30

Analysis of the psychodynamic approach (6)

Answer 30

• had ben used to help influence cognitive behavioural therapy which is used with people who have anxiety.
• one way of treating patients which originates from Freud is free association. Someone talking about their thoughts and feelings in front of a therapist while the therapist writes it down.
• links with the reorganisation theory as they both think harmful memories are pushed away or deleted as they are too harmful for us to think about.
• disagree with memories repressed compared to deleted
• defence mechanisms - sublimation - instead of someone taking their violence out on someone else they channel that anger into boxing for example
• denial is when we tell ourselves that something isn’t a problem when it actually is. E.g. telling yourself you’re prepared for a test at school when you aren’t.

Question 31

Defence mechanisms (4)

Answer 31

• lack of testability/falsifiability as the unconscious can’t be studied directly
• can only be concluded from behaviour or reported thoughts and experiences
• people can appreciate denial, repression, displacement
• case studies that show people are unable to recall traumatic events

Question 32

Information processing (new)

Answer 32

• REM sleep strengths newly-formed connections in the brain which helps learning and memory formation
• nREM sleep is associated with the consolidation of declarative memories (conscious)
• REM sleep seems to be involved in the consolidation of emotional memories. This may be due to the increased activation of the amygdala in this stage of sleep
• infants spend a lot of time in REM sleep which shows its importance in the development of procedural memories
• hippocampus is very involved in the processing of memories especially long term memories
• sleep deprivation studies show that someone who is sleep deprived is less able to recall and remember information

Question 33

Analysis of restoration theory

Answer 33

• compare to other theories
• studies show that the body had a decreased metabolism of up to 10% during sleep - sleep is necessary to repair and replete cellular components necessary for biological functions that become deleted throughout the day