Table 1. EEG bands.

Band Frequency (Hz) Normally
Theta 4-8 • Drowsiness in adults and teens
• Fatigue
Alpha 8-12 • Relaxed/reflecting
• Closing the eyes
Beta 12-30 • Range span: active calm → intense → stressed → mild obsessive
• Active thinking, focus, anxious
Gamma 30-100 • Excited