Sleep EEG

Question 1

States of arousal

Answer 1

During the day there’s a natural change in arousal states. Eg dip at 15.00, sleep/wake etc.

Question 2

Bergers EEG frequencies

Answer 2

Low to high:

Delta

Theta

Alpha

Beta

Gamma

However, EEG signals are very selective (and weird) signals coming from synchronous synaptic currents on the dendrites of cortical neurons (deep structures can’t be reached)

Question 3

Polysomnography

Answer 3

Simultaneous recording of:

EEG (brain waves)
EMG (muscle tone)
EOG (eye movement)

Question 4

Awake

Answer 4

EEG high frequency, but low amplitude
EMG active, high frequency low amplitude
EOG active, high amplitude (saccades)

Question 5

REM

Answer 5

EEG high frequency, low amplitude
EMG low, no muscle tone
EOG active, high amplitude

Question 6

Asleep

Answer 6

EEG low frequency, high amplitude
EMG low, no muscle tone
EOG low, no eye movements (drifts)

Question 7

Normal sleep

Answer 7

90 min cycles
Deep stages in early night
REM sleep in later night

Sleep walking occurs in deep sleep stages
Dreaming occurs in REM sleep