Brain Activity States Flashcards
Slow wave sleep constitutes what percentage of sleep?
75 %
What is the theory behind sleep activation mechanism?
active inhibition of the ascending reticular activating system
Which of the deep cerebral nuclei when stimulated elicits sleep?
Raphe nucleus
Lesions of the _________ decrease REM sleep.
locus ceruleus
What cortical layers are brainwaves primarily derived from?
cortical layers 1 and 2
What are the characteristic of a-waves (EEG)?
8 to 13 waves/s and amplitude of 50 mV
When are a-waves (EEG) present?
during wakefulness but not with activity or intense stimulation
Where are a-waves (EEG) primarily located?
occipital lobes
What are the characteristics of B-waves (EEG)?
14 to 80 waves/s, decreased amplitude compared to a-waves
Where are B-waves (EEG) primarily located?
frontal and parietal lobes during activity
What are the characteristics of theta-waves (EEG)?
4-7 waves/s with increased amplitude
What are the characteristics of g-waves (EEG)?
less than 3.5 waves/s, increased amplitude
When are theta-waves (EEG) present?
parietal and temporal lobes in children
may appear during stress in adults or with brain disorders
When are g-waves (EEG) present?
occur with deep sleep
What are the EEG findings during sleep at each stage?
Stage 1: very light sleep w/ elimination of a-waves
Stage 2: sleep spindles (short a-wave bursts) and K complexes; may exhibit theta-waves
Stage 3: g-waves, may exhibit theta-waves
Stage 4: g-waves
REM: B-waves
