Sleep and Consciousness Flashcards
(29 cards)
Consciousness
awareness of our self and environment; can have different levels of consciousness (different levels of awareness) and can be natural or induced by external factors such as drugs or internal factors such as mental efforts; states range from alertness to sleep
Alertness
you’re awake, aware of who you are, and know what’s going on in the environment, focus your attention, engage in conversation, and code information into your memory
Daydreaming
feel more relaxed; not as focused as alertness; effects can also occur in light meditation (self-induced)
Drowsiness
just before falling asleep/after waking up; can also be self-induced in deep meditation
Sleep
not aware of self or the world around you
-the type of EEG wave depends on the stage
Electroencephalogram (EEG) Brainwaves
your brain knows when you are switching from one stage of sleep to another because of neural rhythms or waves
- beta (12-30 Hz) = associated with awake/concentration; if you are alert for too long, beta levels get high and you experience stress, anxiety, and restlessness
- alpha (8-13 Hz) = daydreaming state; lower frequency than beta waves; disappear during drowsiness but later reappear during deep sleep
- theta (4-7 Hz) = slower/lower frequency than alpha; associated with drowsiness/right after you fall asleep/when you are sleeping lightly
- delta (0.5-3 Hz) = slower than theta; deep sleep or coma
Sleep Stages
brain goes through distinct brain patterns during sleep; 4 main stages (N1, N2, N3, REM) that occur in 90 min cycles
- cycle through these about 5 times per night
- N1 –> N2 –> N3 –> N2 –> REM –> N1
- how long each stage lasts depends on how long you’ve been asleep and your age (babies spend more time in REM sleep whereas adults spend time in slow deep sleep)
- dreams in NREM sleep are not memorable whereas those in REM sleep are
Non-REM N1
dominated by theta waves
- strange sensations (hypnagonic hallucinations) = hearing or seeing things not there
- Tetris Effect = you might see visual images of whatever you were doing that day
- Hypnic Jerks = muscle twitches you sometimes experience as you fall asleep
Non-REM N2
deeper stage of sleep; people in N2 harder to wake; characterized by theta waves, sleep spindles, and K complexes
Sleep Spindles and K Complexes
- Sleep Spindles = burst of rapid brain activity; inhibit certain perceptions to ensure tranquil sleep; associated with sleeping through loud noises
- K Complexes = suppress cortical arousal and keep you asleep; involved in sleep-based memory consolidation during which memories are transferred from short term to long term; occur naturally but also can be induced
Non-REM N3
slow wave sleep; very difficult to awaken; characterized by delta waves; this part of sleep is when sleep talking/walking can occur; declarative memory consolidation
-occurs more somewhere close to falling asleep
REM (Rapid Eye Movement) Sleep
eyes move rapidly under eyelids but most muscles are paralyzed
- “paradoxical sleep” = brain is active through dreaming but body prevents it from doing anything
- most important for memory consolidation and formation of episodic and procedural memories
- combination of alpha, beta, and dyssynchronous waves similar to how seen when awake
- occurs more somewhere close to waking up
- activity of prefrontal cortex decreases and therefore is why our dreams seem to defy logic
Circadian Rhythms
regular body rhythms across a 24-hour period; controlled by melatonin, which is produced by the pineal gland
- control our body temperature, sleep cycles
- daylight is a big queue
- changes as you age - why younger people are night owls and older people go to bed early
Sigmund Freud’s Theory of Dreams
dreams are our unconscious thoughts and desires that need to be interpreted; like an iceberg where conscious is only the tip of iceberg whereas unconscious is submer.
- Manifest Content = literal meaning of the dream
- Latent Content = hidden meaning of the dream
- Dreams have meaning and interpreting them can help us resolve and identify hidden conflict
Activation Synthesis Hypothesis
when dreaming, the brain gets a lot of neural impulses in the brainstem, which can sometimes be interpreted by the frontal cortex
- brainstem = activation; cortex = synthesis
- our brain is simply trying to find meaning from random brain activity so our dreams may not have meaning
Evolutionary Biology’s and Other’s Theories
Evolutionary Biology -threat simulation to prepare for the real world -problem solving -maybe no use Others -maintain brain flexibility -consolidation into long-term and cleaning up thoughts -develop and preserve neural pathways
Sleep Deprivation
people with this are more irritable and have poorer memory and attention
- more susceptible to obesity because body makes more cortisol and releases ghrelin (hunger hormone)
- can also lead to depression as REM sleep is important for processing of emotional experiences
- can get back on track by paying back “sleep debt”
Insomnia
persistent trouble falling asleep or staying asleep
-medication may help but there are limitations due to addiction; psychological training and lifestyle changes better alternative
Narcolepsy
individuals can’t help themselves from falling asleep; various fits (typically 5 min) of falling into REM sleep (1 in 2000 chance to get)
- indications that it may be genetic and due to absence of alertness neurotransmitter
- neurochemical interventions may be effective to treat
Sleep Apnea
occurs in 1 in 20 people; people with it are often unaware
- stop breathing while sleeping – body realizes you are not getting enough oxygen, wake up just long enough to realize you don’t have air and then you fall back asleep without realizing
- can occur 100x a night
- not getting enough N3 sleep
- snoring and feeling fatigued during and after sleep are common indicators
Sleepwalking/Sleeptalking
mostly genetic; occurs during N3 sleep; occurs more in children (as they get more N3 sleep)
Induced States of Consciousness
examples include hypnosis and meditation; does not occur naturally
Hypnotism
usually occurs by getting the person to relax and focus on breathing, and they become more susceptible to suggestion in this state–but only if they want to
-marked by more alpha waves = awake but relaxed state
False Memory
memories that incorporate hypnotizers’ expectations even when not intended
