U4A1 sleep Flashcards
what is a psychological construct?
concept or model that is ‘constructed’ to describe a specific psychological activity.
define consciousness.
a psychological construct that is the level of awareness an individual has over their thoughts, feelings, perceptions and existence.
what are the two types of consciousness?
normal waking consciousness (NWC)
altered state of consciousness (ASC)
name some examples of an altered state of consciousness.
coma, sleep, anaesthetised, drowsy, daydreaming, meditation, alcohol induced.
what is sleep?
sleep is a psychological construct. it is a naturally occurring ASC that involves a loss of awareness and a disengagement with internal and external stimuli.
name some characteristics of REM sleep.
- rapid movement of eye muscles
- highly active brain, less active body
- most muscle movement not possible
- light stage of sleep
- vivid dreaming can occur
- stage increases as the sleep episode goes on
name some characteristics of NREM sleep.
- lack of rapid movement of eye muscles
- muscle movement is more possible
- dreams can occur, but usually not vivid
- often can’t recall dreams when woken here
- stage decreases as the sleep episode goes on
name and describe the three stages of NREM sleep.
NREM stage 1 – light sleep, easily woken, can hear faint sounds, less awareness of themselves and surroundings.
NREM stage 2 – truly asleep, still relatively light sleep, most sleep spent in this stage
NREM stage 3 – deep sleep, difficulty waking, most likely to experience sleeping walking/talking
describe the relationship between sleep cycles and sleep episodes.
a sleep episode is the full duration of sleep time, made up of multiple sleep cycles, which are 90-minute periods made up of REM and NREM which repeat.
what does EEG do?
detects, amplifies and records electrical activity in the brain through brainwaves.
what does EMG do?
detects, amplifies and records the electrical activity of the body’s muscles.
what does EOG do?
detects, amplifies and records electrical activity of eye muscle movement.
what do EEG brainwaves look like in REM?
high frequency and low amplitude.
what do EEG brainwaves look like in NREM1?
high frequency and low amplitude.
what do EEG brainwaves look like in NREM2?
medium frequency and medium amplitude.
what do EEG brainwaves look like in NREM3?
low frequency and high amplitude.
how is REM and NREM sleep displayed through EMG?
REM: low EMG activity
NREM: medium EMG activity
how is REM and NREM sleep displayed through EOG?
REM: high EOG activity
NREM: low EOG activity
what are sleep diaries?
records with self-reported descriptions from an individual about their sleeping periods, as well as judgements about the nature and quality of their sleep.
what is video monitoring?
use of camera and audio technologies to record an individual sleeping.
what is a biological rhythm?
repeated biological processes regulated by internal mechanisms eg. circadian rhythm, ultradian rhythm.
what is a circadian rhythm?
biological + behavioural changes that occur as part of a 24 hour lasting cycle, eg. the sleep-wake cycle.
what is an ultradian rhythm?
biological and behavioural changes that occur in a cycle lasting less than 24 hours, eg. a sleep cycle
what is the suprachiasmatic nucleus (SCN)?
- part of the hypothalamus
- regulates an individual’s sleep-wake patterns
- receives info from both external and internal cues
how does the suprachiasmatic nucleus (SCN) regulate the sleep-wake cycle at night?
- SCN receives internal and external cues
- SCN sends neural messages to pineal glands to produce melatonin
- pineal glands release melatonin into bloodstream, promoting relaxation
what is the role of cortisol in the sleep-wake cycle?
increases alertness and maintains heightened arousal. therefore it is released in the morning to promote wakefulness.
what is the sleep duration and REM percentage for individuals in the neonatal/infancy period?
sleep duration: 12-17h
50% REM, 50% NREM for neonatal
35% REM, 65% NREM for infancy
higher REM due to rapid brain development
what is the sleep duration and REM percentage for individuals in childhood?
sleep duration: 11h
20% REM, 80% NREM
REM reduces as brain development pace steadies
what is the sleep duration and REM percentage for individuals in adolescence?
sleep duration: 9h
20% REM, 80% NREM
may experience biological delayed sleep onset by 1-2h
sleep patterns change due to social factors
what is the sleep duration and REM percentage for individuals in adulthood and old age?
sleep duration: 6-8h
20% REM, 80% NREM
low levels of sleep may cause ill-health + sleeping disorders
what is partial sleep deprivation?
poor quality/quantity of sleep within a 24h period
what is full sleep deprivation?
no sleep within a 24h period
what are some affective effects of sleep deprivation?
changes in emotions + emotional responses from sleep deprivation. eg:
- poor emotional regulation
- irritability and moodiness
- increase in negative emotions
- reduced ability to cope with stress
what are some behavioural effects of sleep deprivation?
changes in actions and ability to control them. eg:
- excessive sleepiness during the day
- increased likelihood of engaging in risk-taking behaviour
- fatigue/lack of energy
- slowed reaction time
what are some cognitive effects of sleep deprivation?
changes in mental processes from sleep deprivation. eg:
- reduced concentration
- impairment of short-term memory
- diminished ability to perform cognitive tasks
- lapses in attention
- impaired decision-making processes
- impaired problem-solving skills
what is BAC?
BAC or blood alcohol concentration is a measure of how much alcohol is in a person’s bloodstream. alcohol slows down the nervous system and decreases alertness.
summarise the dawson + reid study on sleep deprivation and BAC.
participants were required to complete cognitive-motor tasks either sleep deprived or after alcohol consumption.
it was found that a BAC of 0.05 is roughly equivalent to 17h sleep deprivation.
a BAC of 0.10 was found to be roughly equivalent to 24h of sleep deprivation.
what are sleep disorders?
disturbances to typical sleeping and waking patterns.
what are circadian rhythm sleep disorders?
sleep disorders that interfere with the typical regulation of sleep, causing a change in sleep-wake cycles.
explain delayed sleep phase syndrome.
- DSPS is a circadian rhythm sleep disorder where sleeping and waking occurs later than usual
- caused by misalignment between external and internal cues that regulate the circadian rhythm.
- common in adolescence due to biological and social factors.
explain advanced sleep phase disorder.
- ASPD is a circadian rhythm sleep disorder in which sleeping and waking occur earlier than usual.
- caused by misalignment between external internal cues that regulate the circadian rhythm
- more common in older people.
how can shift work impact the sleep-wake cycle?
- impacts sleep-wake cycle as their circadian rhythm is constantly changing and adapting to their environment.
- can lead to difficulty initiating sleep and waking
- effects of shift work include insomnia, fragmented sleep, DSPS or ASPD.
explain how bright light therapy works.
- used to adjust a person’s circadian rhythm through exposure to high intensity light source.
1. individual exposed to light source
2. SCN receives as external cue, regulating sleep-wake cycle
3. this readjusts circadian rhythm and ensures sleep and wake occurs at desired time.
how would bright light therapy work for someone with delayed sleep phase syndrome?
exposed to bright light in the morning, acting as an external cue
how would bright light therapy work for someone with advanced sleep phase disorder?
exposed to bright light in the evening acting as an external cue
define sleep hygiene
practises + habits that promote an individual’s sleep patterns.
eg. time, sound, light, comfort, technology, exercise, etc
define zeitgeber
external cues from the environment that influence the circadian rhythm.
explain how light is a zeitgeber.
- natural light (daylight) is natural blue light that stops melatonin production and promotes wakefulness.
- artificial blue light (technology) acts as an external cue promoting wakefulness.
explain how temperature is a zeitgeber.
- degree of external heat in the environment that can influence the quality and quantity of sleep.
- research suggests 18.3 degrees Celcius is an ideal room temperature.
explain how diet is a zeitgeber.
- some foods and drinks can impact quality and quantity of sleep
- drinks such as caffeine or alcohol
- foods such as spicy foods, or foods high in sugar/fat.
