Sleep and Consciousness Flashcards
Consciousness
awareness of our self and envt- diff levels of awareness can be induced by external factors such as drugs or internal mental efforts. Range from alertness to sleep
Alertness
you’re awake
Daydreaming
feel more relaxed, not as focused, Can also be light meditation (self-induced)
Drowsiness
just before falling asleep/after waking up. Can also be self-induced in deep-meditation
Sleep
not aware of world around you. 4 types
Beta
13-30 Hz, associated with awake/concentration. Increased stress anxiety, restlessness. Constant alertness
Alpha waves
8-13 Hz, in daydreaming. Disappear in drowsiness but reappear in deep sleep. During relaxation
Theta waves
7 Hz, drowsiness, right after you fall asleep
Delta Waves
0-5-3 Hz, deep sleep or coma
EEGs
can measure brainwaves
4 main stages in 90 min cycles
N1–> N2–> N3–> REM
N1
dominated by theta waves. Strange sensations: hypnagonic hallucinations, hearing or seeing things that aren’t there.
Ex: seeing flash of light, or someone calling your name, doorbell etc.
Tetris effect: if you play tetris right before bed, you might see blocks
Hypnic jerks- feeling of falling
N2
deeper stage of sleep, harder to awaken, more theta waves as well as sleep spindles and K-complexes
Sleep Spindles
help inhibit certain perceptions so we maintain a tranquil state during sleep, sleep spindles in some parts of brain associated with ability to sleep through loud noises
K-complexes
supress cortical arousal and keep you asleep, also help sleep-based memory consolidation, even though they occur naturally you can also make them occur by touching someone sleeping
N3
slow wave sleep, delta waves, where walking/talking in sleep happens
REM (rapid-eye movements) stage
most of other muscles are paralyzed, most dreaming occurs during REM sleep, so paralysation inhibits actions, most important for memory consolidation
Combination of alpha, beta, and desynchronous waves
Similar to beta waves seen when awake, sometimes called paradoxical sleep because brain is active and awake but body prevents it from doing anything
waking up during REM sleep prevents memory formation of the dream
Circadian Rhythms
why you get sleepy in afternoon, they’re our regular body rhythms across 24-hour period. Controlled by melatonin produced in pineal gland.
Control body temperature, sleep cycle etc.
Daylight is big queue, even artificial light
Also changes as you age, younger people are night owls but older people go to bed early
Dreaming
during REM sleep, eyes move rapidly under eyelids and brainwaves look like they are completely awake
Prefrontal cortex
activity here decreased in REM sleep, part responsible for logic, why things in our things that defy logic don’t seem weird
Sigmund Freud
dreams are unconscious thoughts and desires that need to be interpreted, little scientific support
Evolutionary Biology
threat simulation, to prepare for real world
problem solving
no purpose
Other
maintain brain flexibility
consolidate thoughts to long-term memory, and cleaning up thoughts. People who learn + sleep retain more than those who do not sleep but role of REM is unclear
Preserve and developing neural pathways bc infants constantly developing new neural networks spend most of time in REM sleep
Dream theories
Freud and Activation Synthesis Hypothesis. Do our dreams have a meaning? Sigmund Freud’s theory of dreams says dreams represent our unconscious feelings/thoughts. Like an iceberg
What happens? Manifest content (ex: monster chasing you)
What is hidden meaning? latent content (ex: job pushing you out) Can help us resolve and identity hidden conflict
Activation Synthesis Hypothesis
brain gets a lot of neural impulses in brainstem, which is sometimes interpreted by the frontal cortex
Brainstem= activation, and cortex= synthesis
Our brain is simply trying to find meaning from random brain activity. Therefore might not have meaning
Sleep deprivation
irritable and poorer memory and can be dangerous when it comes to flying airplanes or driving cars
Sleep disorders
susceptible to obesity- body makes more cortisol and the hunger hormone
can also increase your risk for depression, REM sleep helps brain process emotional experiences which can help protect agains depression
can get back on track by paying back “sleep debt” 7-8 hours sleep for adults
Insomnia
persistent trouble falling asleep or staying asleep
exercising or relaxing before bed can help
Narcolepsy
can’t help themselves from falling asleep. various fits of sleepiness, going into REM sleep can occur any time. 1 in 2000. Indications it’s genetic and linked to absence of alertness neurotransmitter
Sleep apnea
1 in 20 people. Often unaware, stop breathing while sleeping and body realized you’re not getting enough oxygen, wake up just long enough to gasp for air and fall back asleep without realizing. Can happen 100x/night.
Don’t get enough N3 (slow-wave) sleep and snoring is an indication or fatigue in morning
Sleepwalking/sleep talking
mostly genetic occur during N3 and are harmless. Occur more often in children (have more N3)
Apnea
air going into nose/mouth reaches the lungs, tissues around neck may block this airflow- snoring/gasping/pauses in breathing, absence of airflow
Obstructive sleep apnea
Central sleep apnea
presence of apneas without obstruction, presence of apneas without obstruction, problem with the control system for ventilation
Cheyne-Stokes breathing- period of oscillations, then flat etc. problem with the control system for ventilation
Hyperventilation
in lungs or chest wall, can occur at high pCO2 and low pO2, caused by medication/obesity. Chronically elevated pCO2 can lead to right-sided heart failure
Hypnotism
relax and focus on breathing and more susceptible to suggestion in this state. More alpha waves in this stage- an awake but relaxed state.
Used to retrieve memories, dangerous bc memories are malleable and can create false memories
Dissociation Theory
hypnotism is an extreme form of divided consciousness
Social Influence Theory
people do and report what’s expected of them, like actors caught up in their roles
refocused attention, used to treat pain. Reduced activity in areas that process sensory input, doesn’t block it out but might inhibit attention
Meditation
training people to self-regulate their attention and awareness, guided and focused on breathing, mind wanders freely
more alpha waves than normal relaxation in light meditation
In deep meditation have increased theta waves in brain, people who have deep meditation increased activity in prefrontal cortex, right hippocampus and right anterior insula- increased attention control
Can be helpful for people with ADHD or in aging
