Electroencephalography

Question 1

Delta wave

Answer 1

Frequency1-4Hz
Normally foundFrontally in adults and posteriorly in children
Normally seen inSlow wave sleep and in babies. Should not be present when awake, when present if awake this strongly suggests pathology

Question 2

Theta wave

Answer 2

Frequency4-8Hz
Normally foundGeneralised
Normally seen inYoung children, drowsy and sleeping adults, with certain medications, meditation. Small amount seen in awake adults, excessive amount when awake may indicate pathology

Question 3

Alpha wave

Answer 3

Frequency8-12Hz
Normally foundPosteriorly
Normally seen inWhen relaxed and when the eyes are closed (whilst awake)

Question 4

Beta wave

Answer 4

Frequency12-30Hz
Normally foundFrontally
Normally seen inWhen busy or concentrating

Question 5

Sigma wave

Answer 5

Frequency12-14Hz
Normally foundFrontal and central regions
Normally seen in(aka sleep spindles) Bursts of oscillatory activity that occur in stage 2 sleep. Along with k-complexes they are the defining characteristic of stage 2 sleep

Question 6

Gamma wave

Answer 6

Frequency30-100Hz
Normally foundNo specific areas
Normally seen inMedi