Glossary of Sleep-related terms



Frequency bands in EEG analysis

Band Frequency Hz Comment
delta 0.75 - 4.5 slow waves
theta 4.5 - 8
alpha 8 - 12
sigma 12 - 15 spindles
beta1 15 - 20
beta2 >20
This is a widely used definition of the generally used frequency bands. However, exact band limits may differ slightly between laboratories, or depending on circumstances.3