Brainwaves are electrical signals traveling along the cells of the brain (neurons) and they carry information that integrates the different parts of the brain. The Electroencephalogram is what is used to measure different brain states.


Brain Wave Frequency Characteristics
Delta 0.5-4 Hz
  • Predominant in sleep
  • Should be low while awake
  • High delta can interfere with emotional or cognitive processing
Theta 4-8 Hz
  • Pre-sleep, trance
  • Inattentive
  • Distractible
  • Lack of focus
Alpha   8-12 Hz
  • Relaxed (parietal)
  • Spacey
  • Unmotivated
  • Inattentive and depressed
SMR  12-15 Hz
  • Calm, external attention
  • Regulates impulsivity and hyperactivity
  • Promotes body awareness
  • Helps control anxiety; anger
  • Movement Inhibition
Beta  15-20 Hz
  • Active, external attention
  • Enhances cognitive processing
  • Improves concentration, attentiveness, focus
High Beta   22-26 Hz
  • Body tension
  • High state of arousal
  • Excited / anxious / stress

Brain Waves