Sleep & Consciousness Flashcards
Consciousness
- ones level of awareness of the world and ones own existence within the world
- states of consciousness: alertness, sleep, dreaming, altered states (ex. sickness, delirium, coma, dementia)
Alertness
- awake and able to think
- cortisol levels higher
- maintained by neurological circuits in PFC which have fibers that communicate with the reticular formation (structure in brainstem) to keep cortex awake
EEG
records an average of the electrical patterns within different portions of the brain
What are the different stages of sleep?
- awake
- stage 1
- stage 2
- stage 3
- stage 4
- REM
What are the features and EEG waves of the awake stage?
- features: able to perceive, processes, and access information and express information verbally
- waves: Beta and Alpha
What are the features and EEG waves of Stage 1?
- features: light sleep and dozing
- waves: theta
What are the features and EEG waves of Stage 2?
- features: sleep spindles and k complexes
- waves: theta
What are the features and EEG waves of Stage 3?
- features: slow-wave sleep, dreams, declarative memory consolidation, sleep disorders occur at this stage
- waves: delta
What are the features and EEG waves of Stage 4?
- features: slow wave sleep, dreams, declarative memory consolidation, sleep disorders occur at this stage
- waves: delta
What are the features and EEG waves of REM?
- features: appears awake physiologically, dreams, procedural memory consolidation, body is paralyzed
- waves: mostly beta
Beta Waves
- high frequency
- occur when alert or attending to a mental task that requires concentration
- occur when neurons are randomly firing
Alpha Waves
- slower than beta but more synchronized
- occur when awake but relaxing with eyes closed
Theta Waves
- irregular waveforms waveforms with slower frequencies and higher voltages
- occurs once you have dozed off
Delta Waves
- low-frequency, high-voltage sleep waves
- slow waves because there are only a few waves per second
Slow Waves
- correlates with stages 3 and 4 of sleep cycle
- occurs as you fall more deeply asleep
- associated with cognitive recovery, declarative memory consolidation and increased growth hormone release
What are sleep stages 1-4 all part of?
non-rapid eye movement sleep (NREM)
Sleep Cycle
- refers to a single complete progression through the sleep stages
- early in the night SWS predominates whereas later in the night REM sleep predominates
- 50 minutes in children and 90 minutes in adults
Activation-Synthesis Dream Theory
- dreams are caused by widespread, random activation of neural circuitry
- activation can mimic incoming sensory information and may contain pieces of stored memory, desires, and needs
- brainstem = activation
- cortex = synthesis
Problem-Solving Dream Theory
- dreams are a way to solve problems while sleeping
- dreams are untethered by rules of world and allow interpretation of obstacles differently than when awake
Cognitive Process Dream Theory
dreams are merely the sleeping counterpart of stream-of-consciousness
Neurocognitive Models of Dreaming
seek to unify biological and psychological perspectives on dreaming by correlating the subjective, cognitive experience of dreaming with measurable physiological changes
Freud’s Dream Theory
- separated dreams into their manifest content (what one actually sees and hears) and their latent content (underlying significance of these dream elements)
- dreams represent unconscious feelings/thoughts
What two hormones maintain circadian rhythm?
melatonin and cortisol
What are the two categories that sleep disorders are divided into?
- dyssomnias
- parasomnias
