4.3 Consciousness Flashcards
HIGH YIELD
Consciousness
one’s level of awareness of both the world and one’s own existence w/in that world
States of consciousness
alertness, sleep, dreaming, and altered states of consciousness.
Alertness
the state of being awake and able to think, perceive, process, and express info.
How is alertness maintained
- by neurological circuits in the prefrontal cortex at the very front of the brain
- Fibers from the prefrontal cortex communicate w/ the reticular formation, a neural structure in the brainstem, ti keep the cortex awake and alert
- Brain injury → coma
Alertness EEG waves
β and α waves
β waves
high frequency and occur earn the person is alert or attending a mental to a mental task that requires concentration. Occur when neurons are randomly firing
α waves
- occurs when we are awake but relaxing w/ our eyes closed, and are somewhat slower than β wave.
- more synchronized than β waves
Stage 1 of Sleep
- light sleep
- dominated by theta waves (irregular waveforms w/ slower frequencies and higher voltages)
Stage 2 of Sleep
slightly deeper sleep and includes theta waves, sleep spindles, and K complexes
Stage 3 and 4 of Sleep
- even more deeply asleep.
- Aka slow-wave sleep (SWS).
- predominated by Δ waves (low-frequency, high-voltage waves)
- Most sleep-wake disorders occur during these stages
slow-wave sleep (SWS)
- associated with cognitive recovery, memory consolidation, inc growth hormone release.
- Dreaming in SWS focuses on consolidating declarative memories
non-rapid eye movement (NREM)
Stages 1-4 of Sleep
Rapid eye movement (REM) sleep aka paradoxical sleep:
- mind appears close to awake on EEG, but the person is asleep.
- Eye movements and body paralysis occur in this stage.
- Mainly β waves.
- Dreaming in REM focuses on consolidating procedural memories.
- happens more frequent towards the morning
sleep cycle
- approx 90 minutes for adults, approx 50 mins for children
- Normal cycle is Stage 1-2-3-4-3-2-REM or just 1-2-3-4-REM.
Circadian rhythms Circadian rhythms
normally trend around a 24 hour day and is affected by external cues, such as ligh
melatonin
- It’s release is triggered by changes in light in the evening (dec light) → sleepiness
- released by the pineal gland
Cortisol
- levels inc in the early morning and help promote wakefulness
- Produced in the adrenal cortex
dreaming
occurs mainly during REM
Activation-synthesis theory
- dreams are caused by widespread, random activation of neural circuitry
Problem-solving dream theory
dreams are a way to solve problems while you are sleeping and allow interpretation of obstacles differently than during waking hours
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
Dyssomnias
disorders that make it difficult to fall asleep, stay asleep, or avoid sleep
Ex: Insomnia, Narcolepsy, Sleep apnea, sleep deprivation
Narcolepsy
lack of voluntary control over the onset of sleep. Sx include cataplexy, sleep paralysis, hypnagogic and hypnopompic hallucinations
