Title: Hobson and McCarley (1977)

Title: Hobson and McCarley (1977)
Date: 27th February 2017 Assessment Objective: To be introduced to a new biological theory of dreaming. Learning Outcomes and differentiation Grade Challenge questions To describe and explain (with elaboration) what the strengths and weaknesses of the Activation Synthesis Theory are. A* - B What does REM stand for? What are the strengths and weaknesses of To describe the strengths and weaknesses of the Activation Synthesis Theory. C - D To be aware of what the strengths and weaknesses of the Activation Synthesis Theory are. E - F Success Criteria To know what Hobson and McCarleys theory of dreaming is. Do Now! In your book summarise Hobsons and McCarleys Theory (Use KEY WORDS…) Key words: Active Synthesis REM Sensory Blockade Movement inhibition

On a scrap piece of paper write down a;
Do Now… On a scrap piece of paper write down a; Random name Random place Random verb (action)

New Title: Hobson and McCarley (1997)

A biological theory of dreaming…
Hobson & McCarley (1977) – Activation-synthesis theory (very different to Freud’s psychological theory) They are biologists who believed: Dreams are randomly activated messages (neurons firing). Which are synthesised (put together & interpreted) in a story. So, now look at your list with the three random words on. A boring example would be… Teach Verb Mr Sparks Name Bexley Grammar Place

Once we have randomised the post-its you will synthesise your three words into a dream, it can be as elaborate and odd as a real dream might appear. Place Name Verb

Stick in your new dream and create a story about what your dream may be. Place Name Verb

5 STAGES OF SLEEP Hobson & McCarley identified… which happen can up to 8 TIMES A NIGHT Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.

Hobson & McCarley identified 5 stages of sleep: Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.

According to Hobson & McCarley (1977) activation-synthesis takes place during REM sleep (RAPID EYE MOVEMENT). As REM sleep is easily recognised scientists can study brain activity using an EEG (electroencephalograph). During REM sleep, SENSORY BLOCKADE occurs. Incoming information from the senses (sight, sound, touch, taste and smell) is blocked. Furthermore, MOVEMENT INHIBITION also occurs. Physical movements are also blocked so no outgoing movement are made by the body. Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.

However, during REM sleep RANDOM ACTIVATION occurs. Random neurons are activated and impulses provide information as if it were from the senses. This information is generated inside the brain (internally- generated information). The brain tries to make sense of this ‘nonsense’ information by synthesising it into a story. This is the ACTIVATION part of the theory. Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses. This is the SYNTHESIS part of the theory.

They also said that under 5’s do not dream, even though they have REM sleep. Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.

And what they said with regards to the brain must be true because they tested it on cats… Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.

To Summarise … Random – no pattern Activation – to start, begin
Synthesis – to make up, create Sensory blockade – sight, sound, taste etc are stopped Movement blockade – the body cannot move Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.

Read pages 64 – 65. Write down the key words and their definitions into your books. Stage 1 Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep. Stage 2 Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow. Stage 3 Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep. Stage 4 Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep. Stage 5 Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed. The Sequence of Sleep Stages It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.

Do Now… EXAM PRACTISE – have a look at the type of questions you may be asked – can you do these? Write them down and answer these: 1) Could you write a description for the journey that messages are transmitted to the brain? (5) 2) Could you describe the key words: REM, Synthesis, sensory blockade, movement inhibition (6)

Answer to Question 1 Could you write a description for the journey that messages are transmitted to the brain? (5) Message are transported to the brain via the Central Nervous System (CNS), using electrical impulses through neurons. Neurons gather the information from other neurons via lock and key method – meaning that only relevant information is shared with the appropriate neuron. The impulse travel from cell body, along the axon and towards the terminal branches where the electrical impulses jump trough the synaptic gap to the next neuron to the brain where the information is processed.

Answer to Question 2 Could you describe the key words: REM, Synthesis, sensory blockade, movement inhibition (6) REM stands fro Rapid Eye Movement that happens in the 5th stage of sleep. Synthesis is when something is made up, such as a random dream is created in the brain. Sensory Blockade is when the body does not get any sensory messages from outside the body during REM sleep, such as sound, smell, light, touch. Movement inhibition is when the body cannot move, which is why we do not physically act out our dreams.

Quiz Which researchers proposed the activation-synthesis theory of dreaming? (1) What does REM stand for? (1) How many times does REM occur each night? (1) How many different stages of sleep are there in total? (1) ‘During REM sleep no information enters through the senses’ – which key terms describes this statement? (1) What is/are randomly activated during REM sleep? (1) What does EEG stand for? (1) What does and EEG allow scientists to do? (1) ‘During REM sleep the body is paralysed and there is no movement’ – which key term describes this statement? (1) What does the term ‘synthesis’ mean in relation to activation- synthesis? (1) Answers: Hobon & McCarley (1977) Rapid Eye Movement 5 or more Five cycles Sensory blockade Neurons Electroencephalograph Measuring electrical activity in the brain during REM sleep Movement inhibition Where the brain tries to make sense of the random activation and ties it together to make a story.

Evaluation We are now going to consider the strengths and weaknesses of Hobson and McCarley’s (1977) work. Write the subheading: Strengths and Weaknesses Use the textbook to try to find three of each!!!

A biological theory of dreaming… A biological theory of dreaming…
Strengths Strengths Strengths 1) Regular REM Sleep Hobson & McCarley provide an explanation for the regularity of REM sleep. During REM sleep people have movement inhibition and sensory blockade, so there must be something happening in the brain during REM sleep to produce dreams. They explained this through the random activation of neurons. Why is this a strength?

Strengths 2) Development of activation-synthesis Hobson and McCarley’s theory has been continually developed. Hobson said that he thought there was ‘meaning’ in dreams and that some ideas generated by the brain from the random ‘firing’ of neurons could be useful and give the individual new ideas. Thus, there may be an advantage of dreaming that has been passed on through natural selection. E.g. If you wake up with a good idea it might have come from your dreams. Why is this a strength?

Strengths 3) Testing cats…how could they? Hobson and McCarley tested cats to see which areas of the brain were active during REM sleep. They found that the pons and the reticular activating system (RAS) seem to be involved in shutting down physical movement during REM sleep (movement inhibition). Why is this a strength?

Weaknesses 1) Activation-synthesis is not so random
Many people recognise parts of their dreams as something that happened the day before or in their lives. This means that thoughts are not as random as activation-synthesis suggests. Activation-synthesis theory is based on the idea that dreams often show unusual, bizarre situations and do not make full sense. However, in a study only about 34% of 200 dreams did not make logical sense. Why is this a weakness?

Weaknesses 2) Children and dreaming…
Young children under the age of 5 seem to have very few dreams and their dreams are not yet very active, yet they have a normal amount of REM sleep. This suggests dreams are not simply linked to REM sleep. Why is this a weakness?

Weaknesses 3) Lucid dreaming
Lucid dreaming is when people are aware that they are dreaming. This does not fit with activation-synthesis, as it means dreams are controllable and not random. Why is this a weakness? tp://

Now complete a table like the following (you can use the text book to help if you, if needed). Strengths Weaknesses

Evaluating Hobson & McCarley
Strengths Weaknesses Regular REM Sleep Development of activation-synthesis Testing cats…how could they? Activation synthesis is not so random Lucid dreaming Children and dreaming Answer the following exam questions: Explain the activation-synthesis model of dreaming (4 marks) 2) Evaluating the activation synthesis model of dreaming (6 marks)

Strength for activation-synthesis
Extension Questions… Strength for activation-synthesis Read page B1C2 and answer the questions: What evidence is there for the activation-synthesis theory? What did Hobson & McCarley say about activation-synthesis theory in 1999?

Weaknesses of activation-synthesis theory
Extension Questions… Weaknesses of activation-synthesis theory 3) When reporting a dream, what sorts of things do people report? What does this tell us? 4) According to Hobson and McCarley, do dreams make sense? Explain your answer. 5) What is lucid dreaming? 6) What piece of evidence from young children suggests that dreams are not simply linked to REM sleep?

Homework… Complete the revision sheets on: Hobson and McCarley (1977) Key words about neurons and activation- synthesis.

Draw the table below and sift the word soup by placing each of the 16 key terms into one of the two dream theories. Key terms Freud Hobson & McCarley 1. Sensory Blockade 2. Random Activation 3. REM Sleep 4. Free Association 5. Pons 6. Neurons Once you have sifted the key words for Hobson & McCarley you will see which key words are linked to Freud. Make sure you know what each word means… 7. Secondary Elaboration 8. Displacement 9. Synthesis 10. Condensation 11. Dream Analysis 12. Dreamwork 13. Reticular Activating System 14. Slip of the tongue 15. ECG 16.Electroencephalograph Manifest Content

Soup of the day… Key terms Freud Hobson & McCarley 4. Free association
7. Secondary elaboration 8. Displacement 10. Condensation 11. Dream analysis 12. Dreamwork 14. Slip of the tongue 1. Sensory blockade 2. Random activation 3. REM sleep 5. Pons 6. Neurons 9. Synthesis 13. Reticular activating system 16. Electroencephalograph (EEG)

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