U4AOS1A - Demand for Sleep Flashcards
How is consciousness defined?
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Awareness of the world around us and ourselves, including thoughts and feelings
- Internal or external
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Varies along a continuum of awareness
- Total awareness (sustained attention)
- Complete lack of awareness (unconscious in deep coma or vegetative state)
What are the contents of consciousness?
- What we are aware of at any given moment
What is normal waking consciousness?
- Being awake and aware of…
- The external worlds
- Perception and thoughts
- Remaining aware of personal identity
- Percieving the world as real
- Maintaining a sense of time and place
- Most people spend around 2/3 of their day in this state
What is an altered state of consciousness (ASC)?
- Any state of consciousness that is significantly different from NWC or any waking state in terms of level of awareness and experience
- Mental processing of internal and external stimulus shows distinguishable, measureable changes in areas such as…
- Content limitations - Information we choose to attend to and how much we can take in
- Self-control
- Inhibition
- Self-awareness
- Emotional awareness
- Perceptions of time, place and one’s surroundings
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Types
- Naturally Occurring
- Induced
Describe the types of ASC’s
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Naturally Occurring
- In the course of our everyday activities without the need for aid or external influence
- E.g sleep, dreaming, daydreaming, cycles of wakefulness and drowsiness, fatigue
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Induced
- Brought on through some sort of aid
- Intentional - meditation, hypnosis, alcohol ingestion, certain medication or drugs
- Unintentional - accident, disease or disorder
- Types are not mutually exclusive and a naturally occurring ASC like sleep can also be induced through tranquilisers and sleeping pills
Define psychological construct
- An agreed upon concept that is ‘constructed’ to describe specific ‘psychological’ activity, or a pattern of activity that is believed to occur or exist but cannot be directly observed/measured
- Primarily based on research evidence
- Measured indirectly using
- Information provided by the individual
- Behaviour that is demonstrated
- Physiological changes that can be measured (such as recording brain activity)
What is a hypnogram?
- A graph that represents the time period of each stage of sleep, and the transitions between these
- 1 1/2 hour cycles consist of NREM and REM
Define sleep
- A regular and naturally occurring altered state of consciousness (ASC) that involves a loss of awareness and disengagement with internal and external stimuli
- Necessary for restoration and rejuvenation
- Full duration of sleep - Sleep episode
- Fundamental human need alongside nutrition and physical exercise (3 pillars of good health)
What is REM?
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Rapid eye movement sleep
- High levels of brain activity
- Low levels of physical activity
- Heart rate fast and irregular
- Blood pressure rises
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Breathing is shallower, faster and irregular compared to NREM
- Sleeper looks relaxed
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Occasional twitching in small muscles
- Most skeletal muscles are limp
- Appear paralysed
- Dreaming has narrative
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Arousal threshold is variable
- May be like that of N2 or N3
Why is REM sometimes referred to as paradoxical sleep?
- Contradictions in…
- Active brain in an apparently paralysed body
- Internally, brain and body are active; externally body appears calm and inactive/relaxed
Is REM considered deep or light sleep?
- Depends on criteria
- Wakefulness - Light
- Lack of muscle activity - Deep
What is NREM?
- Non-rapid eye movement sleep
- Type of sleep characterised by…
- Lack of rapid eye movement
- Has 3 stages with increasingly deeper sleep (N1, N2, N3)
Describe Stage 1 of NREM sleep
- When sleep begins
- Relatively light sleep
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Physiological
- Lower level of bodily arousal
- Decrease in heart rate, breathing, body temperature and muscle tension
- Slow, rolling eye movements
- Hypnic jerks (involuntary muscle twitches), similar to a spasm
- Can easily be awakened by a gentle nudge or sound
- Low arousal threshold
Arousal Threshold - How much it takes to wake up (similar to pain)
Describe Stage 2 of NREM sleep
- Period of light/moderate sleep - Gradually becomes deeper
- First stage where you are completely asleep
- Continued slowing of heart rate, breathing, muscle activity and body movements
- Body temperature continues to fall
- Eye movements slow
- Brain waves slow further
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Less easily disturbed compared to N1 and requires more stimuli
- But can still be easily aroused
Describe Stage 3 of NREM sleep
- Deep sleep
- Heart rate and breathing slow to their lowest levels
- Muscles completely relaxed - Barely move
- Delta waves are predominant
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Highest arousal threshold
- Difficult to awaken someone
- Harder than in any other stage
- If awoken (especially adruptly), they feel groggy and can take a few minutes to adjust - Referred to as ‘sleep inertia’
- May disappear as sleep progresses
What are similarities between REM and NREM sleep?
- Naturally occurring
- Reduced awareness
Distinguish between REM and NREM sleep (8)
- REM - Fast, jerky eye movement, NREM - Slow minimal eye movement
- REM - Beta brain waves (small), NREM - Delta
- REM - Paralysis, NREM - Movement is possible
- REM - Heart rate increases, NREM - Heart rate decreases
- REM - Dreaming, NREM - Generally no dreaming
- REM - Duration increases, NREM - Decreases
- REM - 20% of sleep, NREM - 80%
- REM - Replenishes mind, NREM - Replenishes body
What is within each sleep episode?
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Sleep cycles between rapid eye movement (REM) sleep and non-rapid eye movement (NREM)
- Each sleep cycle lasts around 90 minutes (ultradian)
- NREM periods tend to decrease as the night progresses, REM periods increase
Distinguish between a sleep episode and sleep cycle
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Sleep Cycle
- Sleep phase comprising NREM sleep and REM sleep
- Occurs within a sleep episode (and is normally repeated a number of times, depending on the duration of the sleep)
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Sleep Episode
- Sleep event
- Starts with sleep onset and ending with a final awakening
- Comprises one or more sleep cycles (but not necessarily complete cycles)
State how sleep cycles and episodes can be voluntary and involuntary
- Voluntary - Intentionally induced by medication
- Involuntary - Tiredness or fatigue
- Both cannot be prevented and can be interrupted
- Voluntary - Alarm Clock
- Involuntary - Arousal due to biological need for urination
What are 4 types of brain waves?
Fish and Chips are good BATD (battered)
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Beta
- Associated with alertness and intensive mental activity during NWC
- Also present when dreaming during a period of rapid eye movement sleep
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Alpha
- Appears when you are awake and alert but mentally and physically relaxed and internally focused
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Theta
- Most commonly produced when you are very drowsy - E.g falling asleep or just before waking
- Can also be produced when awake and engaged in creative activities
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Delta
- Mostly associated with deep, dreamless sleep or unconsciousness
State the frequency and amplitude of the 4 main brainwaves
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Beta
- F - High
- A - Low
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Alpha
- F - Med-High
- A - Low-Med
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Theta
- F - Low-Med
- A - Med-High
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Delta
- F - Low
- A - High
B x D, A x T Matching opposites
What are psychological indicators that can be used to measure consciousness?
- Perceptual and cognitive distortions
- Emotional awareness
- Self control
- Time orientation
- Considered subjective - Based on or influenced by personal feelings, tastes or opinions
What are physiological indicators that can be used to measure consciousness?
- Heart rate
- Body temperature
- Galvanic skin response
- Eye movement (EOG)
- Muscle movement (EMG)
- Brainwaves (EEG)
- Considered objective - Not influenced by personal feelings or opinions in considering or representing facts
What physiological measures can be used to determine consciousness?
x3 DARE
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Electroencephalograph (EEG) - Detects, amplifies and records electrical activity in the brain
- Only EEG has beta, alpha, theta and delta brain waves
- Electromyograph (EMG) - Detects, amplifies and records the electrical activity of the body’s muscles
- Electro-oculograph (EOG)- Detects, amplifies and records electrical activity of the muscles surrounding the eyes
- Collect quantitative, objective data
- Ensure to always state ELECTRICAL activity
Must use full definition in responses referencing techniques
What is an advantage of using physiological measures to determine consciousness?
- Precise observations and measurements can be made during sleep without actually waking the person
What are limitations of an EEG?
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Poorly measures neural activity that occurs below the outer layer of the brain
- Does not provide detailed information about what particular structure is releasing output
- Lengthy time to attach electrodes to scalp
How do you interpret an electroencephalography (EEG)?
- Amplitude - How high/intense
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Frequency - How often
- How many action potentials
What activity would each objective means of measuring consciousness show during REM and NREM sleep?
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EEG
- REM - Beta-like BW
- NREM - Theta-Delta BW
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EMG
- REM - Paralysis, no movement
- NREM - Slow movement
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EOG
- REM - High activity
- NREM - Slow, rolling