AOS 3: SLEEP Flashcards
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primary data
info collected directly from the source by the researcher (or through others) for their own specific purpose.
* from the original source for the first time by the researcher
* e.g: you will collect primary data when you conduct your own scientific investigations.
secondary data
information that was not collected directly by the current researcher but was collected at an earlier time by someone else.
* it has already been collected by some other individual, group or organisation and will not be used for the first time,
* e.g: you using info from ABS for your own research
quantative data
information that is expressed numerically.
* information about the ‘quantity’ or amount of what is being studied (how much or how many of something there is).
* e.g: the height or age of a participant
qualitative data
information that is not expressed numerically.
* information about the ‘qualities’ or characteristics of what is being studied.
* e.g: what something is like, how something is experienced
objective data
information that is observable, measurable, verifiable and free from the personal bias of the researcher.
* e.g: the data can be seen, heard or touched (observable), counted or precisely described (measurable), can be confirmed by another researcher (verifiable) and is factual (free from personal bias).
subjective data
information that is based on personal opinion, interpretation, point of view or judgment.
* this data is determined by the research participants and often cannot always be verified by the researcher.
* often biased, can vary from person to person, day to day from the same person, and is not always entirely accurate.
EEG
used to detect, amplify and record the electrical activity through electrodes manually placed at various points on the scalp.
beta waves
- 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
alpha waves
- 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
theta waves
- 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
delta waves
- lowest frequency
- highest amplitude
- typically associated with the deepest stage of sleep which precedes periods of REM sleep and unconsciousness
EMG
- used to detect, amplify and record the electrical activity of muscles
- when falling asleep, we usually become less and less alert as we drift into deeper stages of sleep
- the higher the level of muscular activity and tone, the more alert we tend to be
EOG
- measures eye movements of eye positions by detecting, amplifying and recording electrical activity in eye muscles that control eye movements
- most commonly used to measure changes in eye movements over time during different types and stages of sleep and while dreaming
sleep diaries
- ‘log’ or journal used to self-report sleep and waking time activities over a period of time (usually one week or more)
- considered to be a subjective measure because they are based on or influenced by personal feelings or interpretations
video monitoring
- monitor and record externally observable physiological responses throughout a sleep episode, including behaviours when falling asleep and when waking
circadian rhythms
- bodily changes that occur as part of a cycle with a duration of approx. 24hrs
- it synchronises all the clocks of your body to a uniform internal time sleep-wake cycle environmental cues
ultradian rhythms
- bodily changes that occur as apart of a cycle with a duration of less than 24hrs
- heart beat
- respiration
- hunger
- hormone secretion
- sleep stages
SCN & melatonin
- 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
NREM 1
- a period of relatively light sleep
- low arousal threshold
- as a result of the muscles relaxing, we sometimes experience involuntary muscle twitches (called hypnic jerks)
- physiological changes
- decrease in heart rate, breathing, body temperature and muscle tension
- slow, rolling eye movements are also likely to be observed.
NREM 2
- a period of light sleep that gradually becomes deeper.
- brain waves also generally slow further during N2.
- although the brain wave pattern is overall slower, it is marked by brief bursts of electrical activity (called sleep spindles)
- physiological changes:
- continued slowing of heart rate, breathing, muscle activity and body movements. Body temperature also continues to fall and eye movements stop.
NREM 3
- a period of deep sleep
- highest arousal threshold
- sleep inertia: if woken abruptly, they can feel
groggy and take several minutes to orient themselves, and usually have a poor memory of sleep events. - physiological changes:
- our heart rate and breathing slow to their lowest levels. muscles are completely relaxed and we barely move. no eye movements.
- brain waves become even slower, with delta waves becoming predominant.
REM
- spontaneous bursts of rapid eye movement during which the eyeballs quickly move beneath the closed eyelids, darting back and forth and up and down in jerky, but coordinated movements.
- brain wave pattern associated with REM sleep is
generally like that produced during alert wakefulness. - physiological changes:
- the heart rate is faster and more irregular. blood pressure rises, and breathing is shallower, faster and more irregular when compared with NREM sleep. however, the sleeper looks totally relaxed.
- paradoxical sleep: sleeper paralysed but body is active
demands for sleep across the life span
new borns/ children/ adolescents/ adults
newborns:
* 50% REM and 50% NREM
* 14 -15 hours
children:
* REM DECREASE NREM INCREASE
* 11-13 hours
adolescents:
* 80% NREM 20% REM
* 8-9 hours
adults:
* 80% NREM 20% REM
* 8 hours
sleep across the lifespan graph
- 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 - the proportion of time spent in REM sleep decreases markedly during the first two years and then remains relatively stable through to old age
- decrease in the proportion of NREM sleep that persists through to old age
sleep deprivation
a general term used to describe a state caused by inadequate quantity or quality of sleep, either voluntarily or involuntarily.
* quantity- amount of sleep (objective measure)
* quality- how well we feel we have slept (subjective measure)
sleep debt
- is the accumulated amount of sleep loss from insufficient sleep.
- the difference between the amount of sleep that is needed to function at an optimal level and the amount a person actually gets.
- e.g: a nightly sleep debt of 60 minutes between Monday and Friday would add up to a total sleep debt of 5 hours.
- generally, after a period of sleep deprivation, only some of the sleep debt needs to be recovered.
affective functioning
- mood changes
- heightened anxiety
- depression
- irritability
- lack of motivation
behavioural functioning
- slower reaction times
- clumsiness
- risk-taking behaviours
cognitive functioning
- lack of concentration
- impaired memory (trouble with encoding, not retrieval)
- illogical/irrational thoughts, poor decision-making
- trouble with simple, monotonous tasks
dawson and reid experiment method
- Dawson and Reid obtained their results using
40 participants in a within subjects experiment
with counterbalancing
dawson and reid findings
- the results showed that the performance impairment effects of moderate sleep deprivation are equivalent to or greater than the amount of alcohol that is deemed legally unacceptable when driving, working and/or operating dangerous machinery.
- 0.10% BAC = 24 hrsw/o sleep
- 0.05% BAC = 17 hrs w/o sleep
delayed sleep phase disorder
features & ppl likely to experience
- condition in which the major sleep episode is delayed in relation to the desired sleep time or what is considered a conventional time.
- there is a natural tendency to go to sleep later and therefore wake up later than what is normal according to ‘society’s clock’.
- prominent symptoms: sleep-onset insomnia, difficulty awakening at the desired or necessary time, and excessive sleepiness.
- DSPS tends to emerge or worsen during adolescence and continue into early adulthood.
advanced sleep phase disorder
features & ppl likely to experience
- a persistent disturbance of the sleep–wake cycle characterised by advance of the major sleep episode to an earlier time compared to desired or conventional sleep times.
- the disorder results in compelling evening sleepiness, early sleep onset, and awakening earlier than the desired or necessary times.
- has been proposed that it may be due to an age-related deterioration in the biological clock (SCN) that regulates the sleep–wake cycle, the reduction in melatonin production that is evident among older people and/or a shift in the circadian timing of melatonin secretion to 2–4 hours earlier than normal.
bright light therapy
involves timed exposure of the eyes to intense but safe amounts of light. When used for circadian
rhythm sleep disorders, the aim is to shift an individual’s sleep–wake cycle to a desired schedule, typically the day–night cycle of their physical environment.
- right time of day at the right intensity for the right amount of time.
sleep hygiene
- involves practices that tend to improve and maintain good sleep and full daytime alertness.
- includes behaviours and environmental factors that can be adjusted to help with a good night’s sleep and waking feeling rested and ready to take on the day’s activities.
- sleep hygiene is often used interchangeably with sleep habits because it involves changing basic lifestyle habits that influence sleep onset, good quality sleep and alertness during the normal waking period.
zeitgebers
environmental time cues that can be used to
improve sleep–wake patterns and consequently mental wellbeing.
entrainment
zeitgebers in the external environment are used by the SCN to adjust circadian rhythms to a 24-hour day. The SCN is believed to do this on a daily basis. When the SCN adjusts or resets the sleep–wake cycle to match the environmental day-–night cycle through the influence of a zeitgeber, the circadian rhythm is said to be entrained
- e.g: all our circadian rhythms are entrained to the regular 24-hour, day–night cycle of our external environment.
day light zeitgeber
- natural light from the sun in the course of a typical day, our circadian sleep–wake cycle becomes closely synchronised with sunrise and sunset, keeping us awake during the day and sleeping when it’s dark. The specific timing of the cycle, however, is influenced by the timing of the light exposure.
blue light zeitgeber
- keeps us alert by suppressing the secretion of melatonin that makes us feel drowsy.
- helpful during the day, it becomes unhelpful at night when we’re trying to sleep.
- too much exposure to blue light in the evening disrupts our circadian rhythms leaving us feeling alert instead of drowsy and ready for sleep.
temperature zeitgeber
- sleep is most likely to occur when core body temperature decreases, and much less likely to occur during the rises when the body is preparing for wakefulness.
- about two hours before falling asleep, our core body temperature starts to decrease under circadian control, coinciding with the secretion of melatonin.
eating and drinking zeitgeber
- food can be disruptive just before sleep. Our digestive system also follows a circadian rhythm linked to the day–night cycle. It is ready to digest food during the day, but not at night time.
