Consciousness and sleep Flashcards
Evolutionary (circadian) theory
Emphasises the relationship of sleep to circadian rhythms. The idea that sleep is adaptive and evolved to enhance survival.
Pros: Accounts for why and when we sleep
Con: Does not account for loss of awareness and alertness during sleep
Restoration theory
Sleep is to recover from depleting activities during wake up time that use up the body’s physical and mental resources.
NREM: restores and repairs body (growth and tissue repair)
REM: Restores body and is involved in learning and memory (the consolidation of memory)
REM REBOUND
catching up on REM sleep immediately following a period of lost REM sleep by spending longer in REM sleep than usual next time sleeping.
Pros: Research evidence
Cons: A physically disabled person confined to their bed has a similar sleep cycle to a physically active individual
Automatic process
Requires little conscious awareness and mental effort, minimal attention and does not interfere with the performance of other activities
Beta brainwaves
High frequency, low amplitude
- Alertness and intensive mental activity during NWC
- Present during states of tension, anxiety, threat and fear
Delta brainwaves
Low frequency, high amplitude
- Deep, dreamless sleep or unconsciousness
- Begin to appear in stage 3 of NREM sleep
- Stage 4 - deepest sleep
Theta brainwaves
Med frequency, mix of medium, high, and low amplitude
- Very drowsy, falling asleep, just waking
- Awake and engaged in creative activities, excited and deeply meditating
Controlled processes
Conscious, alert awareness and mental effort in which the individual focuses their attention on achieving a particular goal
Alpha brainwaves
Low to medium frequency, low to medium amplitude
- Awake and alert but mentally and physically relaxed and internally focused
- Drowsy or relaxed state, just prior to falling asleep
Selective attention
Choosing and attending to a specific stimulus to the exclusion of others
Daydreaming as an altered state of consciousness
A temporary change in one’s normal state
A temporary shift on the consciousness continuum
Divided attention
Ability to distribute our attention and undertake two or more activities simultaneously
EOG
Electro-occulargraph
Measures eye movement by detecting, amplifies and recording electrical activity in eye muscles that control eye movements
EMG
Electromyograph
Detects, amplifies and records the electrical activity of muscles
EEG
Electroencepholograph
Detects, amplifies and records patterns of electrical activity in the brain
Circadian rhythm
Changes in bodily functions and activities during a cycle of 24 hours
Area of the hypothalamus - the suprachiasmatic nucleus - is called the ‘master’ biological clock. It regulates timing and activity of the sleep wake cycle.
The brain induces sleep by alerting the pituitary gland to secrete melatonin until exposed to light stimulus
Ultradian rhythm
Changes in bodily functions and activities during a cycle of less than 24 hours
Psychological construct
Cannot be directly observed eg) consciousness
Self reports
Written or spoken responses to questions, statements or instructions
Sleep diary
A self recorded report of an individuals sleep and waking time activities
Video monitoring
Recording of externally observable physiological responses during a sleep episode
Methods to study consciousness
EEG, EMG, EOG, self reports, sleep diaries, video monitoring
Infant’s sleep
Sleep duration = irregular
Fewer sleep cycles but cyclic alternation of NREM-REM sleep is present
REM sleep = restless, may contain movement
Sleep onset occurs through REM
Proportion of REM sleep is relatively high
Young children
Total sleep time decreases as kid gets older
REM sleep decreases, NREM increases
Slow wave deep sleep is quantitatively and qualitatively different from adults
Adolescents
Total sleep time decreases, REM sleep too
NREM = 3 +4 stages decline and 2 increases
Slow wave deep sleep decreases more
Adults
Sleep appreciably less
Average 8 hours
Decline in duration of sleep episode and in REM and NREM sleep
Stages 3+4 eventually disappear
Alcohol and sleep deprivation
After sleep deprivation, performance on cognitive tasks decreased to a level equivalent to a person under the influence of alcohol
Performance on tasks tended to decrease
Influence mood states, cranky, interfere with ability to think clearly
Sleep wake shifts in adolescence
Timing of melatonin secretion peaks later (1 to 2 hours)
Results in a delayed seep onset, sleep wake cycle shift
Psychological and social factors may influence sleep habits
Dysomnias
Problems with sleep wake cycle processes, difficulty falling or staying asleep, inability to prevent sleep onset, a disruption to the timing of the circadian sleep wake cycle
I.e. sleep-onset insomnia
Persistent difficulty falling asleep at the usual time
Parasomnia
Inappropriate disruption of sleep by some abnormal sleep-related event
i.e. sleepwalking
Getting up from bed and walking about or performing other behaviours while asleep
During NREM 3_$
Partial sleep deprivation
A state caused by inadequate quantity or quality of sleep, voluntarily or involuntarily. Having less sleep than what is normal required
Partial sleep deprivation
Affective
Emotional response threshold is lowered, emotional reactivity, can cause overreacting
Compromise brain’s ability to process emotional information
Partial sleep deprivation
Behavioural
May lead to involuntary lapses into sleep called microsleeps
Reduces efficiency, tend to take longer to finish tasks, slower reaction times, more mistakes
Partial sleep deprivation
Cognitive
Reduce alertness and ability to stay focused on task
Errors are more likely when a task lacks interest or complexity
CBT
Aims to find solutions on how to change a person’s current thoughts and behaviours so they can function better now and in the future
Cognitive - assists the individual to recognise and change inappropriate or dysfunctional attitudes, beliefs and other thoughts about their sleep
Behavioural - helps the individual develop good sleep habits to avoid behaviours that prevent them from sleeping well
Bright light therapy
To treat circadian phase disorders
Involves timed exposure of the eyes to intense but safe amounts of light
Circadian rhythm phase disorders
Group of sleep disorders involving sleep disruption that is primarily due to a mismatch between an individual’s sleep-wake pattern and the pattern that is desired or required
