sleep Flashcards
unit 4 aos 1
consciousness
awareness of something either internal or external to yourself
normal waking consciousness (NWC)
the state of consciousness in which an individual is awake and aware
altered state of consciousness (ASC)
any state of consciousness that is significantly different from normal waking consciousness
sleep
a regular and naturally occurring altered state of consciousness that involves a loss of awareness and disengagement with internal and external stimuli
-REM and NREM
psychological construct
a concept used to describe a mental process, psychological state or trait; they are used to describe something that is believed to exist, because we can measure its effects, but we cannot directly observe or measure it
eg sleep
five measures of sleep
-electroencephalograph (EEG)
-electro-oculography (EOG)
-electromyograph (EMG)
-sleep diary
-video monitoring
electroencephalograph (EEG)
detects, amplifies, and records the electrical activity of the brain
features of brainwaves from EEG
-amplitude: height of wave
-frequency: number of waves per seconds
the lower the frequency and the higher the amplitude = the deeper the sleep
electro-oculography (EOG)
detects, amplifies, and records the electrical activity of muscles around the eye
REM = high activity
NREM = no-little activity
electromyograph (EMG)
detects, amplifies, and records electrical activity of muscles
-the deeper the sleep, the more relaxed muscles are = less activity except for REM sleep
sleep diary
a log used to self-record and self-report sleep and waking activities over a period of time
-subjective info which can be biased
video monitoring
participants complete normal night routine and sleep time while being recorded
advantages and disadvantages of video monitoring
advantage:
-can re-watch footage recorded
disadvantages
-the artificiality if completed in a sleep lab/being recorded– it’s not the same as being in your room
-the artificiality of the attachments – eg being connected to an EEG machine whilst you sleep
-hard to interpret the data – what behaviours should be recorded, and people interpret things differently
sleep cycle
-periods of around 90 minutes where we experience REM and NREM sleep
-in a typical sleep we go through 5 or 6 sleep cycles
REM sleep
-20-25% of sleep is REM, occurs at the end of each sleep cycle
measures of sleep in REM
-EEG: high frequency, low amplitude
-EMG: low activity
-EOG: high activity
NREM
-75-80% of sleep is NREM
measures of sleep in NREM
-EEG: the deeper the sleep = the lower the frequency and the higher the amplitude of brain waves
-EMG: muscle movements is more likely to occur during this stage
-EOG: the deeper the sleep = the less activity
characteristics of NREM stage 1
-entry point into sleep (except for infants)
-relatively light sleep
-lasts around 2-10 minutes
characteristics of NREM stage 2
-deeper sleep than stage 1
-lasts around 20-30 minutes, but lengthens as a sleep episode progresses
characteristics of NREM stage 3
-deepest sleep
-lasts around 20-40 minutes but decreases as sleep episode progresses
circadian rhythm
a biological rhythm involving physiological, psychological, or behavioural changes that occur as part of a cycle with a duration of about 24 hours
sleep-wake cycle
-an example of circadian rhythm
-time we spend asleep and the time we spend awake
-largely endogenous
zeitgebers
-environmental time cues which can influence sleep-wake cycle
-eg sunlight, artificial light, clocks
-exogenous
endogenous
originating within an organism
exogenous
originating outside an organism
ultradian rhythms
-a biological rhythm involving physiological, psychological, or behavioural changes that occur as part of a cycle shorter than 24 hours
-eg sleep, sleep cycle
location and purpose of suprachiasmatic nucleus
-located within hypothalamus
-regulates sleep-wake cycle by controlling activity of pineal gland
function of pineal gland
-produces melatonin, which makes us drowsy
how does SCN produce right amount of melatonin
-scn receives light from environment
-depending how much light is received, the scn then signals pineal gland to either secrete more or less melatonin (the more light the less melatonin, including artificial lights)
duration of sleep of newborns and infants
decreases from 16 to 12 from birth to age of two
REM and NREM in newborns and infants
-50% of sleep is REM
-experiences REM when they first go to sleep
sleep patterns in newborns and infants
fragmented sleep
duration of sleep in children
decreases from 12 to 10 hours
REM and NREM in children
-REM: 20-25%
-NREM decreases through childhood - 50% is stage 3 NREM
sleep patterns in children
not unusual for REM to be skipped in first sleep cycle
duration of sleep in adolescents
decreases from 10 to 9 hours
REM and NREM in adolescents
-REM: 20-25%
-NREM decreases - less stage 3 and more stage 2
sleep patterns in adolescents
delayed sleep onset
duration of sleep in adults
decreases from 9 to 7 hours
REM and NREM in adults
-REM: 20-25%
-Further decrease in stage 3 and NREM overall
duration of sleep in elderly people
6-7 hours
REM and NREM in elderly people
-REM: 20-25%
-NREM further decrease in sleep - little to no stage 3
sleep patterns in elderly people
-sleep becomes more fragmented
-more naps during the day
-tends to become sleepier in early evening and wake up earlier in the morning
sleep deprivation
inadequate quantity and/or quality of sleep
partial sleep deprivation
having less sleep (either quantity or quality) than what is normally required
full sleep deprivation
no sleep within a 24 hour period
effects of partial sleep deprivation on affective functioning
-impaired ability to regulate emotions
-impaired ability to process emotional information
-increased emotional reactivity
-increased negative emotions
effects of partial sleep deprivation on behavioural functioning
-impaired performance on tasks
-impaired reaction time
-microsleeps
-increased risk-taking behaviours
-fatigue
effects of partial sleep deprivation on cognitive functioning
-difficulties maintaining attention and concentration
-difficulties in thinking and reasoning
sleep deprivation vs bac
BAC of 0.05 = 17 hours of partial sleep deprivation
BAC of 0.10 = 24 of full sleep deprivation
sleep deprivation vs bac - affective
-sleep deprivation = negative emotions
-alcohol = negative or positive emotions
sleep deprivation vs BAC - cognitive
have similar effects such as:
-slower mental processes
-decreased ability to reason and problem solve
-reduced ability to make decisions quickly and effectively
circadian rhythm sleep disorder
any sleep disorder caused by a mismatch between a person’s internal circadian rhythm and their actual or required sleep schedule
potential causes of circadian rhythm sleep disorders
-an issue with the biological mechanisms that regulate our sleep wake cycle
-our physical environment
-our lifestyle
delayed sleep phase syndrome
a type of circadian rhythm sleep disorder in which sleep and waking occur later than usual
advanced sleep phase disorder
a type of circadian rhythm sleep disorder in which sleep and waking occur earlier than usual
shift work
-in itself it is not a circadian rhythm sleep disorder, but can cause one if regularly scheduled during our usual sleep period
-this is because one is working when their melatonin is naturally low and sleep when adrenaline and cortisol are naturally high
bright light therapy
-involves timed exposure of the eyes to intense but safe amounts of light - typically done through artificial light such as a light box
what does bright light therapy do?
-aims to reset our biological clock: the SCN - this is by supressing the secretion of melatonin and in turn promoting alertness at the appropriate times
-occurs during early morning to treat DSPS and early evening to treat ASPD
sleep hygiene
practices that tend to improve and maintain good sleep and full daytime alertness
entrainment
the process of adjusting a circadian rhythm so that it is in sync with zeitgebers of our environment
how does light influence sleep?
-strongest zeitgeber - blue light (main source is sun)
-exposure to light promotes wakefulness by supressing secretion of melatonin
-if exposure to artificial light at night, SCN receives conflicting signals, interfering with sleep
how does temperature influence sleep?
-drowsiness increases as core body temp decreases
-temp is an influential zeitgeber - referring to temp of external environment as cooler environments promote sleep
how can eating and drinking habits influence sleep?
-some foods positively or negatively impact sleep
-eating too close to bedtime can make it harder to fall asleep
-going to bed hungry or overly full can negatively impact sleep - quality and sleeping patterns
-caffeine promotes wakefulness
-alcohol makes it easier to fall asleep, but impairs quality of sleep
-diets high in fatty and sugary foods can negatively impact sleep quantity and quality
-spicy foods can impair sleep from increased body temps, and stimulates and increases metabolic processes which makes it harder to fall asleep
