U4AOS1A - Demand for Sleep Flashcards
1
Q
How is consciousness defined?
A
-
Awareness of the world around us and ourselves, including thoughts and feelings
- Internal or external
-
Varies along a continuum of awareness
- Total awareness (sustained attention)
- Complete lack of awareness (unconscious in deep coma or vegetative state)
2
Q
What are the contents of consciousness?
A
- What we are aware of at any given moment
3
Q
What is normal waking consciousness?
A
- 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
4
Q
What is an altered state of consciousness (ASC)?
A
- 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
-
Types
- Naturally Occurring
- Induced
5
Q
Describe the types of ASC’s
A
-
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
-
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
6
Q
Define psychological construct
A
- 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)
7
Q
What is a hypnogram?
A
- 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
8
Q
Define sleep
A
- 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)
9
Q
What is REM?
A
-
Rapid eye movement sleep
- High levels of brain activity
- Low levels of physical activity
- Heart rate fast and irregular
- Blood pressure rises
-
Breathing is shallower, faster and irregular compared to NREM
- Sleeper looks relaxed
-
Occasional twitching in small muscles
- Most skeletal muscles are limp
- Appear paralysed
- Dreaming has narrative
-
Arousal threshold is variable
- May be like that of N2 or N3
10
Q
Why is REM sometimes referred to as paradoxical sleep?
A
- Contradictions in…
- Active brain in an apparently paralysed body
- Internally, brain and body are active; externally body appears calm and inactive/relaxed
11
Q
Is REM considered deep or light sleep?
A
- Depends on criteria
- Wakefulness - Light
- Lack of muscle activity - Deep
12
Q
What is NREM?
A
- 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)
13
Q
Describe Stage 1 of NREM sleep
A
- When sleep begins
- Relatively light sleep
-
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)
14
Q
Describe Stage 2 of NREM sleep
A
- 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
-
Less easily disturbed compared to N1 and requires more stimuli
- But can still be easily aroused
15
Q
Describe Stage 3 of NREM sleep
A
- Deep sleep
- Heart rate and breathing slow to their lowest levels
- Muscles completely relaxed - Barely move
- Delta waves are predominant
-
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
16
Q
What are similarities between REM and NREM sleep?
A
- Naturally occurring
- Reduced awareness
17
Q
Distinguish between REM and NREM sleep (8)
A
- 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
18
Q
What is within each sleep episode?
A
-
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
19
Q
Distinguish between a sleep episode and sleep cycle
A
-
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)
-
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)
20
Q
State how sleep cycles and episodes can be voluntary and involuntary
A
- 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
21
Q
What are 4 types of brain waves?
Fish and Chips are good BATD (battered)
A
-
Beta
- Associated with alertness and intensive mental activity during NWC
- Also present when dreaming during a period of rapid eye movement sleep
-
Alpha
- Appears when you are awake and alert but mentally and physically relaxed and internally focused
-
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
-
Delta
- Mostly associated with deep, dreamless sleep or unconsciousness
22
Q
State the frequency and amplitude of the 4 main brainwaves
A
-
Beta
- F - High
- A - Low
-
Alpha
- F - Med-High
- A - Low-Med
-
Theta
- F - Low-Med
- A - Med-High
-
Delta
- F - Low
- A - High
B x D, A x T Matching opposites
23
Q
What are psychological indicators that can be used to measure consciousness?
A
- Perceptual and cognitive distortions
- Emotional awareness
- Self control
- Time orientation
- Considered subjective - Based on or influenced by personal feelings, tastes or opinions
24
Q
What are physiological indicators that can be used to measure consciousness?
A
- 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
25
Q
What physiological measures can be used to determine consciousness?
x3 DARE
A
-
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
26
Q
What is an advantage of using physiological measures to determine consciousness?
A
- Precise observations and measurements can be made during sleep without actually waking the person
27
Q
What are limitations of an EEG?
A
-
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
28
Q
How do you interpret an electroencephalography (EEG)?
A
- Amplitude - How high/intense
-
Frequency - How often
- How many action potentials
29
Q
What activity would each objective means of measuring consciousness show during REM and NREM sleep?
A
-
EEG
- REM - Beta-like BW
- NREM - Theta-Delta BW
-
EMG
- REM - Paralysis, no movement
- NREM - Slow movement
-
EOG
- REM - High activity
- NREM - Slow, rolling
30
Q
What psychological measures can be used to determine consciousness?
DISCLAIMER - Presents both qualitative and quantitative
A
-
Sleep Diaries
- Record containing self-reported descriptions from an indivdual about their sleeping periods
- Includes an estimated time spent sleeping
- Has judgments they might have about the quality and nature of their sleep
-
Video Monitoring
- The use of camera and audio technologies to record an individual as they sleep
- Both objective and subjective
31
Q
What is a sleep lab?
A
- A place where people with and without a sleep problem or disorder can be studied for research purposes
- Individuals with a sleep problem may also be observed, diagnosed and treated
- Artificial environment
32
Q
What are limitations of a sleep laboratory?
A
- Artificial environment → Data may be inauthentic
- EEG, EOG & EMG may bring discomfort
- Individual may be self conscious due to monitoring
- Sleep may be intentionally interrupted by researchers for the purposes of studying sleep patterns
33
Q
What are the uses of a sleep diary?
A
- Provides insights that can only be gained from the individual themself
34
Q
What are the advantages of a sleep diary?
A
- Can’t obtain the specific data in any other way
- Non-intrusive
- Cost-Effective
- Does not require specialised equipment
35
Q
What are the disadvantages of a sleep diary?
A
- Extremely subjective
- Individuals may be ashamed to be completely honest
- Requires compliance
36
Q
What are the uses of video monitoring?
A
- Able to see things like…
- Sleepwalking
- If someone gets up a lot during their sleep
- If they toss and turn more than usual
37
Q
What are the advantages of video monitoring?
A
- In their own home, not a sleep lab - Natural and non-obtrusive
- Can be a valuable tool for children who have trouble verbalising their experience
- Too young to complete a sleep diary
- More valid to measure sleep quantity
- Useful in uncovering sleep disturbances the individual may not rememeber (sleep walking)
38
Q
What is a disadvantage of video monitoring?
A
- Don’t know reasoning behind behaviour
39
Q
Define biological rhythms
A
- Repeated natural biological processes that are regulated by internal mechanisms
- Cyclical
- Two types
- Circadian
- Ultradian
40
Q
Define biological clock
A
- Innate timing mechanism that regulates the cycle of a biological rhythm
- Functioning is genetically determined and occurs at the cellular level
- Level of melatonin indicates state of body clock
- SCN is a notable example
41
Q
Define circadian rhythms
A
- Biological processes that occur as part of a cycle that lasts 24 hours
- Coordinate timing of activity of body systems
- Allow for optimised functioning at certain time points
- Relate to presence of light and dark
42
Q
Define endogenous
A
- Orginating within an organism
43
Q
Define exogenous
A
- Originating outside an organism
44
Q
What are criteria that can be used to classify a biological rhythm as a circadian rhythm?
A
- Duration of 24 hours
- Repeats every 24 hours
- Persists in the absence of external cues (endogenous)
- Can adjust to match new external cues (entrainable)
- Controlled/regulated by a biological clock
45
Q
Define ultradian rhythms
A
- Biological processes that are repeated within cycles that last less than 24 hours - Sleep cycle is a type (90 minutes of REM and NREM)
- Other examples include…
- Digestion
- Heart rate
- Appetite
- Arousal
46
Q
Distinguish between circadian and ultradian rhythms
A
- Circadian are 24 hours
- Ultradian are less than 24 hours
47
Q
Define sleep-wake cycle
A
- 24-hour cycle that is made up of time spent sleeping and time spent awake and alert
- Type of circadian rhythm (with ultradian rhythm occuring within)
- Determined by internal body clock located in the hypothalamus
- Also regulates our level of body temperature and hormone secretions
48
Q
Define melatonin
A
-
Hormone released by the pineal gland to induce sleep as part of the sleep-wake cycle
- Typically at night time
- Low levels of light
- Helps to sync internal events to external cues
- Therefore regulates circadian rhythm and syncs sleep-wake cycle to night and day
- Amount of light influences how much is released
- Artificial light can inhibit the release (smartphones, tablets and other electronic devices)
49
Q
How is melatonin released?
A
- Lack of light is detected by the eye
- Stimulates suprachiasmatic nucleus (SCN)
- The SCN signals the pineal gland in the hypothalamus to release melatonin
🔗 - Serotonin involved in making melatonin
50
Q
What is the suprachiasmatic nucleus?
A
-
Double nucleated structure in hypothalamus that regulates an individual’s sleep-wake patterns
- Regulates by sending neuronal messages to the pineal gland to secrete more/less melatonin
- When light is detected from the eyes, the SCN also…
- Increases body temperature
- Releases cortisol to promote alertness and other arousal activities
- Master biological clock
- Influenced by zietgebers
Zietgebers - External cues
51
Q
What would happen if the SCN was intentionally destroyed?
A
- Circadian rhythms and cyclical behaviours are likely to become completely disorganised or dysfunctional
52
Q
What is the pineal gland?
A
- A gland in the brain responsible for the production and release of melatonin
53
Q
Explain from a biological perspective why digital media use for a prolonged period before sleeping can affect sleep onset
A
- Artificial lighting can mimic natural lighting
- SCN uses lighting as an external cue to signal to the pineal gland to inhibit the release of melatonin
- Therefore in the presence of a device the natural time for melatonin to be released is delayed
- Causes sleep onset to occur later
54
Q
Define sleep onset
A
- Transition period from being awake to being asleep
- Length of time to transition is sleep latency
55
Q
What is the restoration theory?
A
- Theory that explains why we have the need to sleep
- Underpinned by the belief the sleep is needed for the body to replenish its resources
56
Q
Do newborns have a different NREM to REM ratio? Why?
A
- Instead of 80/20, they have 50/50
- This is because it boosts brain growth and development
- Important because they have rapid brain development
- Changes to 80/20 around 3 years of age
57
Q
What are 4 reasons that adolescents have inadequate amounts of sleep?
A
- Poor sleep habits
- Hormonal changes
- Exposure to blue light
- Busy schedules
58
Q
How can sleep debt accrue over time?
A
- If the body continues to get poor quality or insufficient amounts of sleep
- As sleep debt builds, body and brain functioning begin to deteriorate
59
Q
Can you get rid of sleep debt?
A
- Yes
- Through one night of uninterrupted sleep
60
Q
What are six prominent changes to sleep that appear as we age?
A
- From birth onward total gradually decreases
- Time spent in REM decreases during the first 2 years and remains stable until old age
- N3 decreases, replaced mostly by N2
- Circadian phase delay in adolescence (prefer going to sleep later)
- After adolescence, shift in circadian phase - Sleep earlier
- Awakenings in sleep increase from adulthood to old age
61
Q
Why might an infant only have one or two cycles in a sleep episode?
A
- Their circadian rhythms are not yet fully developed/ synchronised with the day-night cycle
62
Q
What is a biological reason that adolescents tend to get less sleep than they need?
A
- There is a biologically driven change in their sleep-wake cycle that delays sleep onset for 1-2 hours
63
Q
Do sleep needs decline with age?
In order words, do sleep requirements decline with age?
A
- No
- Remains constant through adulthood
- Misconception due to the fact that as adults get older…
- They tend to have a harder time falling asleep
- Sleep lightly
- Wake up more often
- Spend less time in deep, refreshing sleep
- Have a higher chance of developing a sleep disorder (sleep apnea, insomnia)
64
Q
Describe the distinguishing features of an infant’s sleep
A
- Total 16 hours in first month
- Fragmented due to feeding and nuturing
- Reduces to 12-13 hours by age 2
- 50% REM reducing to 25% at around age 2
-
Sleep onset initially REM
- Normalises at around 2 or 3 months with maturation (circadian rhythm)
- 12 months - Majority of sleep as a single episode in the evening
- Daytime napping common☺
65
Q
Describe the distinguishing features of a child’s sleep
A
- Sleeps less than infants and more than adolescents
- Approximately 11 hours
- Proportion of REM sleep continues to decrease
- About half NREM is N3/N4
- Decreases markedly from about age 10
- Daytime napping decreases (especially at school age)
66
Q
Describe the distinguishing features of an adolescent’s sleep
A
- Total sleep continues to decrease
- Approximately 9 hours
- Tendency to have less than required amount of total sleep
- Sleep-wake cycle shift delays sleep onset by 1-2 hours
-
Proportion of REM continues to decrease
- Mid-adolescence sleep episode begins to resemble young adults
- N3/N4 progressively declines
- N2 increases
67
Q
Describe the distinguishing features of an adult’s sleep
A
- Total sleep time is averaged at about 8 hours per night
- NREM 75-80%; REM 20-25%
-
Gradual decline in…
- Total sleep time
- Time spent in NREM and REM
- N3/N4 with eventual loss
- Increase in sleep latency and awakenings
68
Q
Describe the distinguishing features of an elderly person’s sleep
A
- Decreases through old age to about 6 hours
- NREM and REM continue to decrease
- Little to none of N3
- Tendencies of…
- More fragmented sleep/ night awakenings
- Becoming sleepier in the early evening
- Waking earlier compared to younger adults
- Sleep disorders more common
69
Q
At what age does the proportion of REM sleep stabilise?
A
- 6 years old
- REM takes up 20%
- Remains stable over the rest of the life span
70
Q
Explain the importance of light in regulating the circadian rhythm
A
- Without external cues the circadian rhythm runs slightly longer than 24 hours
- Exposure to regular light through the consistent day-night cycle helps to reset a person’s circadian rhythm to exactly 24 hours
- Makes the internal rhythm in line with the external environment
71
Q
When does sleep onset begin at NREM?
A
- By 3 months it changes from beginning at REM to beginning at NREM
- This is because at birth the circadian rhythm…
- Has yet to fully develop
- Has not synced with external cues (zietgebers) of light/dark cycle
72
Q
What is the purpose of light/moderate sleep?
A
- About half of a total sleep episode is spent in N2 (NREM)
- Evolutionary purpose for safety
- Allows us to wake in response to potential threats
73
Q
Compare the sleep-wake cycle of an adolescent to an adult
A
- Adolescents have their sleep onset delayed by 1-2 hours
- Goes to bed later than an adult
- Adolescents need more sleep than an adult
- Wake up later than an adult
