unit 4 aos 1 Flashcards
consciousness
the level of awareness an individual has to something internal or external to yourself. includes thoughts, feelings, perceptions & existence
- divided into normal waking consciousness and altered states of consciousness
what is a naturally occurring altered state of consciousness
naturally occurring in the course of our everyday activities without the need for any aid, differs in awareness from normal waking consciousness
continuum of awareness
varies from total awareness to complete lack of awareness
- total awareness
- daydreaming
- meditative state
- hypnotised
- asleep
- anaesthetised
- coma
- total lack of awareness
sleep
- a regular and naturally occurring altered state of consciousness that involves a loss of awareness and disengagement with internal and external stimuli
- cycle through NREM and REM in each sleep episode
- each cycle lasts around 90 mins, with a transition between each of the stages of NREM, and a period of REM
characteristics of NREM sleep
- replenishment of the body
- 80% of total sleep episode
- delta brain waves
- reduced physiological activity & no eye movement
- 3 stages:
- N1= light sleep, 5 mins (4-5% of cycle)
- N2 = moderate sleep, 10-25 mins, (50% of cycle)
- N3 = deep sleep, 20-40 mins (10-15% of cycle)
NREM stage 1
- light sleep
- low level of bodily arousal (HR, body temp, respiration)
- slow, minimal eye movement
- 5% of total sleep time
NREM stage 2
- moderate sleep, gradually gets deeper
- continued slowing of physiological body activity
- brain waves slow further, with brief bursts of activity
- eye movement stops
- 50% of total cycle
NREM stage 3
- deep sleep
- muscles completely relaxed
- no eye movement
- slow delta waves occurring
- less time spent in N3 as the night progresses
- 10-15% of total cycle
characteristics of REM sleep
- replenishment of mind
- beta brain waves
- 20% of total sleep episode
- spontaneous bursts of rapid eye movement, eyes move back and forth in coordinated movements
- internally active while body looks calm
- periods lengthen and occur closer together as sleep episode progresses (20-25% of cycle)
measurement of physiological responses associated with sleep
- electroencephalography (EEG)
- electromyography (EMG)
- electro-oculargraphy (EOG)
- sleep diaries
- video monitoring
electroencephalography (EEG)
- detects, amplifies and records different brain waves produced:
> beta: alert
> alpha: mentally & physically relaxed
> theta: drowsy
> delta: deep sleep - brain waves are spontaneous, rhythmic electrical impulses that come from different brain areas
electromyography (EMG)
detects, amplifies and records the electrical activity of muscles produced by sleep
electro-oculargraphy (EOG)
detects, amplifies and records electrical activity of muscles around the eyes during sleep
sleep diaries
- log used to self-record & report sleep & wake time over a period of time
- subjective data
video monitoring
record externally observable physiological responses throughout a sleep episode, including behaviours when falling asleep and waking
regulation of sleep by internal biological rhythms
changes that repeat themselves through time in a cyclical way, linked to cyclical changes in environmental cues, such as sunrise & sunset, day length, amount of light
- circadian rhythm
- ultradian rhythm
biological clock
innate timing mechanism that regulates the cycle of a biological rhythm
circadian rhythms
involves physiological, psychological or behavioural changes that occur as part of a cycle with a duration of ~24 hrs (sleep-wake cycle)
ultradian rhythms
- involves physiological, psychological or behavioural changes that occur as part of a cycle that is less than 24 hours (sleep cycle)
- heartbeat, respiration, sleep
- complete sleep cycle is ~90 mins
melatonin
- produced by the pineal gland and is involved in initiation & regulation of sleep-wake cycle
- helps feel sleepy, amount of melatonin in the blood is associated with alertness
- light determines melatonin production
- low light = produce more melatonin
- high light = produce less melatonin
suprachiasmatic nucleus (SCN)
- detects light through eyes and responds by signalling pineal gland to release melatonin
- adjusts our sleep-wake cycle accordingly by signalling pineal gland to release more or less melatonin based on how much light is detected
- initiates an increase in body temp & releasing hormones to promote alertness
- keeps sleep-wake cycle in sync with day-night cycle
age related changes in sleep
- time spent sleeping decreases as we get older, especially in the amount of N3 sleep
trends in sleep across lifespan
- infancy: ~ 16 hours a day, 50% REM, 50% NREM
- childhood: ~11-13 hrs a day, 20-25% REM, 75% NREM
- adolescence: ~9 hrs a day, 20-25% REM, 75% NREM
- adulthood: ~7-8 hrs a day, 20% REM, 80% NREM
- later adulthood: ~6 hrs
sleep restoration theory
sleep is needed to replenish the mind & bodys resources, explains why we sleep
- REM is higher when studying
- NREM is higher when exercising