S&D Bio Approach Flashcards
What is the biological theory?
It suggests dreams are from random brain activity and they are useless.
What is the activation synthesis hypothesis?
It states dreams result from neurons in brain areas called pons firing randomly which sends messages to the neurocortex - it then tries to make sense of the messages and creates narratives that fit with the random signals, forming dreams.
What did Hobson and McCarley state?
They stated activation synthesis takes place during REM sleep, sensory blockade occurs and movement inhibition occurs.
What is sensory blockade?
Incoming information from the senses is blocked.
What is movement inhibition?
Physical movements are blocked.
What else happens during REM sleep?
Random activation.
What is random activation?
Random neurons are activated, impulses provide information as if it were from the senses (activation part) and the information is generated inside the brain and it tries to make sense of the nonsense information by sorting it into a story (synthesis part).
What are 2 strengths about the biological theory?
1 - It contains lots of lab experiments as evidence such as Dement and Kleitman so the results should be reliable and the view has increased reliability.
2 - There is lots of evidence that we repair during sleep so it’s clear in everyday life that sleep deprivation occurs when we don’t get enough sleep e.g Peter Tripp.
What are 2 weaknesses about the biological theory?
1 - It assumes human behaviour follows a logical order which is a weakness because humans have thoughts and emotions meaning biology cannot predict how every human will behave in the same situation.
2 - It can’t explain dreams that make sense or include events that happened during the day so biological theories of dreaming might not be accurate as it’s clear people dream about what’s going on in their lives.
What is the role of the brain during sleep?
During the day adenosine builds up in the brain’s neurons as a natural by-product each hour and when we sleep the build up is cleared and replaced y energy in the form of glycogen e.g the stimulant drug caffeine blocks adenosine building up.
What controls circadian rhythms
Our body clock tracks time and controls our circadian rhythms and our body’s natural processes.
How do circadian rhythms work?
The hypothalamus controls circadian rhythms and the SCN (a group of neurons in the hypothalamus) gets information from nerve cells in the eyes about whether it’s light or daark.
What is a zeitgeber?
Light functions as a zeitgeber.
How is melatonin induced?
Neurons project from the SCN to the pineal gland.
Example?
Wolfson and Clarkson found in a study of 3000 teenagers that those who slept longer got better grades.
What happens during stage 1 and 2 of sleep?
The individual is easily woken, can still hear noise and heart and breathing rate begin to slow.
What happens during stage 3 and 4 of sleep?
The individual is harder to rouse but a stimulant important to them can break the barrier, blood pressure drops and EEG shows higher amplitude.
What happens during REM sleep?
Eyes move rapidly under eyelids and the body is temporarily.
What is Oswald’s restoration theory?
Oswald suggested that sleep is a period of calm and quite necessary for the body and brain to replenish themselves and repair any deterioration from the day.
What happens during NREM sleep?
He suggested the body is repaired (repairing minor injuries).
What happens during REM sleep?
The brain is repaired during REM sleep (neurotransmitters are replenished).
What are 2 strengths of the restoration theory?
1 - Shapiro et al found after an ultramarathon, the runners’ sleep lasted 90 mins longer and NREM sleep lengthened so we can see in practice that NREM sleep is lengthened after exercise which is a strength as it suggests NREM must repair the body if this was the stage that was lengthened.
2 - It makes more sense than other explanations for sleep as sleep must fulfil an essential function such as repair which is a strength because if we didn’t need sleep to repair, the behaviour would have died out.
What are 2 weaknesses of the restoration theory?
1 - The evidence for what sleep repairs is conflicting because some evidence suggests sleep is essential for the brain only, not the body. Horne found that sleep deprived athletes could still effectively play sports.
2 - There are other explanations for sleeping longer after physical exertions such as the heating up the brain (Horne and Harley). This is a weakness because NREM sleep may not be for the reparation of the body if we can induce longer periods of NREM without physical exertion.
What was the aim of the Dement and Kleitman study?
To find a link between sleep stages and dreams.
What was the method of the D&K study?
Lab experiment.
What was the procedure of the D&K study?
7 males and 2 females came to a sleep lab for a polysomnography, and they were told to avoid caffeine and alcohol during the day. They slept in the lab and machines recorded their brain activity. They were woken several times and asked if they were dreaming, what they were dreaming and how long the dream had lasted.
What were the results of the D&K study?
They found participants were more likely to say they had been dreaming if woken during REM sleep, doing so on 80% of wakings compared to 9% when woken during NREM. They also said their dreams had been shorter if woken 5 minutes after REM sleep started compared to 15 minutes after.
What are 2 strengths of the D&K study?
1 - It was a lab experiment so cause and effect can be established making the study more reliable.
2 - They used controls such as no caffeine or alcohol which is a strength because these are factors that affects sleep and by avoiding them the study is more reliable.
What are 2 weaknesses of the D&K study?
1 - They used a small sample size so the results cannot be generalised to a large population.
2 - The artificial setting may have affected the quality of their sleep so the results may not be natural or valid.
What are 4 conclusions of the D&K study?
1 - Most of the time when we are in REM sleep, we are dreaming.
2 - The longer we are in REM sleep, the longer we perceive our dreams to be.
3 - The direction of our eye movements during REM correlates to the content of our dreams.
4 - The sleep stages can be accurately pinpointed through the use of an EEG.
