Consciousness Flashcards
Consciousness
one’s level of awareness of both the world and one’s own existence within that world
Alertness
a state of consciousness in which we are awake and able to think.
can experience certain level of physiological arousal
cortisol levels tend to be higher, and EEG waves indicate a brain in the waking state
Fibers from the prefrontal cortex communicate with the reticular formation, a neural structure located in the brainstem, to keep the cortex awake and alert.
Electroencephalography (EEG)
records an average of the eletrical patterns within different portion of the brain
Four EEG patterns:
beta waves
alpha waves
theta waves
delta waves
Beta waves
have a high frequency and occur when the person is alert or attending to a mental task that requires concentration.
occur when neurons are randomly firing
Alpha waves
occur when we are awake but relaxing with our eyes closed, and are somewhat slower than beta waves.
have more synchronized waves than beta waves
Stage 1
detected on the EEG by the appearance of theta waves
At this point, EEG activity is characterized by irregular waveforms with slower frequencies and higher voltages
Stage 2
EEG shows theta waves along with sleep spindles and K complexes
Stage 3 & 4
“slow wave sleep (SWS)”
EEG activity grows progressively slower until only a few sleep waves per second are seen.
Have delta waves: low frequency, high voltage sleep waves
During these stages, its very difficult to wake someone up from their sleep
Non rapid eye movement (NREM) sleep
Stages 1-4
there is usually little or no eye movement during these stages. Dreaming is rare during NREM sleep, and muscles are not paralyzed as in REM sleep
Rapid eye movement (REM) sleep
arousal levels reach that of wakefulness, but the muscles are paralyzed
aka: paradoxical sleep (PS) … sometimes: desynchronized sleep because one’s heart rate, breathing patterns and EEG mimic wakefulness but the individual is still asleep
stage where dreaming most likely occurs
Sleep cycle???
a single complete progression through the sleep stages
????
Meditation
decreases heart rate and blood pressure
on the EEG, meditation resembles Stage 1 sleep with theta and slow aha waves
produces a sense of relaxation and relief from anxiety and worrying
Hypnosis
state in which a person appears to be in control of his or her normal functions, but is in a highly suggestible state
Starts with hypnotic induction, in which the hypnotist seeks to relax the subject and increase the subjects level of concentration.
effective hypnosis requires a wiling personality and lack of skepticism on the part of the patient.
Sleep deprivation
results from as little as one night without sleep, or from multiple nights with poor- quality, short duration sleep.
Can cause psychosis
people who are permitted to sleep normally after sleep deprivation often exhibit REM Rebound, and earlier onsey and greater duration of REM sleep compared to normal
Night terrors
common in children
periods of intense anxiety that occur during slow-wave sleep
high heart rate, rapid breathing
these usually occur during SWS
child is difficult to wake
and does not remember the next morning
Sleepwalking (somnambulism)
occurs during SWS
has no recollection of what they did during their sleepwalk
awakening a sleepwalker will not harm the person; usually suggested to guide them back to bed
Insomnia
difficulty falling asleep or staying asleep
Narcolepsy
lack of voluntary control over the onset of sleep
symptoms are unique and include cataplexy: a loss of muscle control and sudden intrusion of REM sleep during waking hours, usually caused by an emotional trigger
Sleep paralysis
a sensation of being unable to move despite being awake
hypnagogic and hynopompic hallucinations
hallucinations when going to sleep or awakening
Sleep apnea
inability to break during sleep
can be obstructive or central
Obstructive: occurs when a physical blockage in the pharynx or trachea prevents airflow
Central: occurs when the brain fails to send signals to the diaphragm to breathe.
Dyssomnias
disorders that make it difficult to fall asleep, stay asleep or avoid sleep and include insomnia, narcolepsy and sleep apnea
Parasomnias
abnormal movements or behaviors during sleep, and include night terrors and sleep walking
REM stage is the stage that :
dreaming most likely occurs
Sleep cycle
a single complete progression through the sleep stages
the cycle changes throughout the night
Circadian rhythms
normally trend around a 24 hr day
Changes in light in the evening trigger release of ______ by the ____
melatonin; pineal gland
Which hormone is released by the pineal gland?
Melatonin
Melatonin is released by what gland?
Pineal Gland
A steroid hormone produced in the adrenal cortex would be?
Cortisol
Coritsol promotes
wakefulness
Cortisol levels increase during the early morning of the day because :
increasing light caused the release of Corticotropin releasing factor (CRF) from the hypothalamus
Corticotropin releasing factor (CRF) causes release of which hormone?
Adrenocortictropic Hormone (ACTH)
Adrenocortictropic Hormone (ACTH) is released from which gland
the anterior pituitary
which stimulates cortisol release which contributes to wakefulness
Most dreaming occurs during:
REM
Activation - synthesis theory
where dreams are caused by widespread, random activation of neural circuitry.
This activation can mimic incoming sensory information
Problem - solving dream theory
says that dreams are a way to solve problems while you are sleeping
Cognitive process theory
states that dreams are merely the sleeping counter part of stream - of - consciousness
Neurocognitive models of dreaming
unifies biological and psychological perspectives of dreaming by correlating the subjective, cognitive experience of dreaming with measurable physiological changes
