PY 105 Chapter Notes - Chapter 3: Slow-Wave Sleep, Activation-Synthesis Hypothesis, Circadian Rhythm
Consciousness
• Awareness that we have of ourselves, our internal states and the environment
o Important for reflection and directing our attention
States of Consciousness
• Alertness - ability to remain attentive to what is going on
o Can be impaired by narcolepsy, ADD, depression and chronic fatigue
• Alertness and arousal are controlled by structures within the brainstem - reticular formation (RAS)
Sleep
• Stages
o Polysomnography (PSG) - multimodal technique used to measure physiological processes
during sleep
• EEG: measures electrical impulses in the brain
• EMG: measures skeletal muscle movements
• EOG: measures eye movements
There are four stages of sleep
1. Stage 1: Non-REM
a. EEG - theta waves, low intensity and intermediate frequency
b. EOG - slow rolling eye
c. EMG - moderate activity
2. Stage 2
a. K complexes and sleep spindles
b. K complex - duration of half second, large and slow
c. Sleep spindles - bursts of waves, frequency = 12-14 Hz
d. No eye movement
e. EMG - moderate ectivity
3. Stage 3
a. Slow wave sleep (SWS)
b. Delta waves - high amplitude and low frequency
c. Deepest level of sleep
d. EOG - no eye movement
e. EMG - moderate muscle movement
4. REM
a. Quick eye movements
b. EEG - beta waves, low intensity, jagged
c. EMG - low/no muscle movement
d. Dreams
Have multiple sleep cycles
Sleep and Circadian Rhythms
• Sleep heals the body
• Circadian rhythm - biological waxing and waning of alertness over 24 hour day (biological clock)
• Light influences biological clock by activating light sensitive proteins in the retina
o These proteins send signals to the brain's pineal gland (produces melatonin)
Dreaming
• During REM stage
• REM rebound - if you miss REM one night, make up for it the next time you sleep
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Document Summary
Consciousness: awareness that we have of ourselves, our internal states and the environment. States of consciousness: alertness - ability to remain attentive to what is going on, can be impaired by narcolepsy, add, depression and chronic fatigue, alertness and arousal are controlled by structures within the brainstem - reticular formation (ras) Stages: polysomnography (psg) - multimodal technique used to measure physiological processes during sleep, eeg: measures electrical impulses in the brain, emg: measures skeletal muscle movements, eog: measures eye movements. Sleep heals the body: circadian rhythm - biological waxing and waning of alertness over 24 hour day (biological clock) Light influences biological clock by activating light sensitive proteins in the retina: these proteins send signals to the brain"s pineal gland (produces melatonin) Dreaming: during rem stage, rem rebound - if you miss rem one night, make up for it the next time you sleep.
