CHAPTER 6: SLEEP Flashcards
(33 cards)
1
Q
sleep
A
- naturally occuring and reversible altered state of conscious
- characterised by a reduction in awareness and responsiveness to external surroundings
- unique brain wave activity and distinguishable physiological changes
- considered as a psychological construct
- fundamentally private in nature to an individual
2
Q
consciousness
A
awareness of your own internal mental processes
- thoughts, feelings, sensations and perceptions and your awareness of the external world around you
- a psychological construct
3
Q
psychological construct
A
a concept that cannot be objectively observed or measured directly through the collection of data, but is widely understood to exist
4
Q
altered state of consciousness
A
- is any state of consciousness that is distinctly different from normal waking consciousness in terms of level of awareness and experience
- can be naturally occuring or induced
- mental processing of internal and external stimuli shows distinguishable, measureable changes
- self-control, inhibition, self-awareness, emotional awareness, perceptions of time, place and one’s surroundings
5
Q
naturally occuring altered state of consciousness
A
a type of altered state of consciousness that occurs w/o intervention
- sleep
- day dreaming
6
Q
induced altered state of consciousness
A
a type of altered state of consciousness that occurs due to a purposeful action or aid
- meditation
- hypnosis
- influence of alcohol/ drugs
7
Q
normal waking consciousness
A
- associated with being awake and aware of objects and events in the external world, and one’s sensations, mental experiences and own existence
- is not one single state
- varying levels or ‘degrees’ of awareness when we are awake
- generally includes all states of consciousness that involve heightened awareness
8
Q
nrem sleep
A
- characterised by a progressive decline in physiological activity
- 3 distinct stages
- 80% of a sleep episode in people of school age and older
- it is thought that our body is repairing itself during NREM sleep
9
Q
nrem stage 1
A
- traditional phase between wakefulness and sleep
- light sleep
- physiological responses begin to slow down
- brain activity
- heart rate
- body temp
- once not distrubed for a couple of mins in n1 a person can quickly move to n2
- 5 to 10 mins
10
Q
nrem stage 2
A
- light sleep
- physiological responses continue to slow down
- still wakes relatively easily
- burst of brain activity help resist being woken up by environmental stimuli such as noises
- this stage is experienced the most
- lasts approx. 20 mins
11
Q
nrem stage 3
A
- deep sleep
- physiological responses are at slowest
- most difficult to wake up
- known as ‘slow-wave sleep’
- experience more in the first half of the night than the second half
- as sleep progresses, a person experiences less n3 sleep and may not at all in the last one or two cycles
12
Q
rapid eye movement sleep - REM
A
- eyes make quick daring movements behind closed eyelids
- physiological activity increase
- brain activity resembles wakefulness and heart rate & heart rate increase
- voluntary muscles are seemingly paralysed and twitch only intermittently
- most vivid and memorable dreams occur during REM sleep
- 20% of sleep episode depending on age
13
Q
hypnogram
A
- a line graph that represents that stages of sleep plotted against time
- time on x axis
- types and stages of sleep on y axis
- display the sleep architecture or patterns of a sleep episode
- a typical night’s sleep of an adult consisting of five sleep cycles
14
Q
sleep research
measurement of physiological responses associated with sleep
A
- enable researchers to obtain quantitative data on bodily processes and changes that occur as we fall asleep, during sleep itself and as we awaken from sleep
- includes info about (depending on what info is required):
- electricity activity of the brain
- eye movements
- body’s muscle tone or ‘tension’
- other physiological responses such as heart rate, body temp, respiration, blood oxygen, blood movements
- snoring noises can also be record
15
Q
electroencephalograph (EEG)
A
- device that detects, amplifies and records general patterns of electricity activity of the brain over a period of time
- electrodes are attached to the surface of the scalp to detect summative electrical activty produced by neurons in the cerebal cortex below
- limitations
- poorly measures neural activity that occurs below the outer layer of the brain (e.g cortex)
- does not provide detailed information about which particular structures of the brain are activated and what their specific functions might be, especially areas beneath the cortex
16
Q
beta waves
A
- highest frequency
- lowest amplitude
- irregular
- associated w/ normal waking consciousness when alert, attentive to external stimuli and intensive mental activity
- e.g. someone who is awake and physically or mentally active, with eyes open and concentrating on some mentally engaging task
17
Q
alpha waves
A
- high frequency (slower than beta waves)
- low amplitude (slightly larger than beta waves)
- regular configuration (teeth of a comb)
- typically associated with a relaxed, calm, internally focused, wakeful state, with eyes closed
18
Q
theta waves
A
- medium frequency (slower than alpha & beta)
- mixture of high & low amplitude waves
- typically associated with drowsiness, falling asleep, awakening from sleep, creative activites, excitement and when in a deep meditative state in which there is not awareness of external stimuli
- when falling asleep there is usually a changeover from alpha to theta waves across a period of several mins
19
Q
delta waves
A
- lowest frequency
- highest amplitude
- typically associated with the deepest stage of sleep which precedes periods of REM sleep and unconsciousness
20
Q
electromyograph (EMG)
A
- used to detect, amplify and record the electrical activity of muscles
- recordings generally show the strength of electrical activity in occurring in the muscles, which indicates changes in muscle activity (movement) and muscle tone(tension)
- when falling asleep, we usually become less and less alert as we drift into deeper stages of sleep
- sleep studies using EMG recordings show that while this is occurring, our muscles progressively relax (e.g. decrease in muscle tone) and there is less movement
- the higher the level of muscular activity and tone, the more alert we tend to
21
Q
electro-ocular graph (EOG)
A
- measures eye movements of eye positions by detecting, amplifying and recording electrical activity in eye muscles that control eye movements
- records of EOG are displayed as line graphs (similar to EEG & EMG)
- most commonly used to measure changes in eye movements over time during different types and stages of sleep and while dreaming
22
Q
sleep diaries
A
- ‘log’ or journal used to self-record and self-report sleep and waking time activities over a period of time (usually one week or more)
- most often used in conjunction w/ physiological measured such as EEG and EMG to support the assessment of sleep disturbances or disorders, particularly their nature, severity and possible causes
- considered to be a subjective measure because they are based on or influenced by personal feelings or interpretations
- records may be kept of
- the time when trying to fall asleep, believed sleep onset or wake up time
- the number, the time and length of awakenings
- the number of caffeinated drinks, meals, exercise, phone use
23
Q
subjective measure vs objective measure
A
- subjective data
- is often biased
- can vary from person to person, day to day from the same person
- is not always entirely accurate
- objective data
- e.g electronic recording device
- is impartial
- not subject to personal opinion or interpretation
24
Q
video monitoring
A
- monitor and record externally observable physiological responses throughout a sleep episode, including behaviours when fallvng asleep and when waking
- can be done at home
- these types of responses can be examined together with those of other types of recordings, then linked to different sleep stages, sleep types or the specific
- responses that may be targeted:
- changes in posture or body position (‘tossing and turning’)
- sleep-related breathing problems
- what happens when awakening from a nightmare or night terror
- behaviours associated with sleep walking
25
biological mechanisms
- circadian rhythm
- bodily changes that occur as part of a cycle with a duration of approx. 24hrs
- like the conductor of an orchestra, it synchronises all the clocks of your body to a uniform internal time
- sleep-wake cycle
- environmental cues
- ultradian rhythm
- bodily changes that occur as apart of a cycle with a duration of less than 24hrs
- heart beat
- respiration
- hunger
- hormone secretion
- sleep stages
26
sleep-wake cycle
- our bodies are turned into a 24 hour sleep-wake cycle which is a regular **circadian rhythm**
- determined by SCN located in the hypothalamus
27
suprachiasmatic nucleus (SCN)
- an internal body clock (SCN) located in the hypothalamus
- SCN receives information about the amount of incoming light from the eyes and sends neuronal messages to the nearby pineal gland to secrete more or less of the hormone **melatonin** into the blood
- more light = stop melatonin
- less light = more melatonin
28
melatonin
- hormone that is involved in the initiation of sleep and in the regulation of the sleep-wake cycle
- produced by the pineal gland and released into blood stream to reach every organ in the body
- amount of melatonin present in the blood is associated with alertness
- higher melatonin level is associated with greater drowsiness
29
ultradian rhythms: stages of sleep
experience two types of sleep during sleep: REM & NREM
- both these types of sleep occur in continuous cycles, one after the other
- a period of REM usually follows each period of NREM
- both types of sleep is characteristically different and has contrasting features and functions
- linked to specific brain waves and changes in bodily activity
- NREM sleep has been described as sleep w/ a relatively inactive brain in a body that can move and REM sleep as sleep with an active brain in a paralysed body
30
a typical night sleep in a healthy adult
- approx. 7-8 hours total
- 1.5 (90min) cycles
- NREM decreases
31
NREM vs REM
NREM
- 80% sleep in NREM
- as night progresses time spent in NREM decreases
- NREM typically associated w/ physical restoration of the brain and body's resources
- e.g. new brain and muscle cells created
- NREM consists of 3 stages that range from light sleep to deep sleep
REM
- 20% sleep in REM
- begins approximately 1/12 hours after sleep onset and increases as the night progresses
- characterised by rapid eye movement and a loss of muscle tone
- the brain is showing a high level of activity while the body remains inactive (to the point of paralysis)
- nerve impulses below the neck are blocked in order to stop us acting out our dreams
- REM sleep is often referred to as paradoxical sleep because of the brains activity and the body’s inactivity- it’s a paradox !
32
sleep across the lifespan graph
1. total sleep time gradually decreases as we get older
- significant reduction in stage 3 deep sleep as the sleep episode progresses and the frequent awakenings throughout the episode
2. the proportion of time spent in REM sleep decreases markedly during the first two years and then remains relatively stable through to old age
3. decrease in the proportion of NREM sleep that persists through to old age
33
dreams in REM sleep
* most dreaming occurs during REM sleep
* dreams also occur during all NREM sleep stages
and can be as bizarre as those in REM sleep
- generally shorter,
- less frequent,
- less structured,
- less likely to be recalled and
- less vivid than those of REM dreams.
- REM dreams have a narrative structure and consist of storylines
- NREM dreams may be better referred to as ‘dream
imagery’ – more colours and abstract shapes
