Comparison table

Comparison of EEG bands
Type Frequency (Hz) Location Normally Pathologically
Delta up to 4 frontally in adults, posteriorly in children; high amplitude waves
  • adults slow wave sleep
  • in babies
  • Has been found during some continuous attention tasks (Kirmizi-Alsan et al. 2006)
  • subcortical lesions
  • diffuse lesions
  • metabolic encephalopathy hydrocephalus
  • deep midline lesions
Theta 4 – 7 Hz Found in locations not related to task at hand
  • young children
  • drowsiness or arousal in older children and adults
  • idling
  • Associated with inhibition of elicited responses (has been found to spike in situations where a person is actively trying to repress a response or action) (Kirmizi-Alsan et al. 2006).
  • focal subcortical lesions
  • metabolic encephalopathy
  • deep midline disorders
  • some instances of hydrocephalus
Alpha 8 – 12 Hz posterior regions of head, both sides, higher in amplitude on dominant side. Central sites (c3-c4) at rest .
  • relaxed/reflecting
  • closing the eyes
  • Also associated with inhibition control, seemingly with the purpose of timing inhibitory activity in different locations across the brain (Klimesch, Sauseng, & Hanslmayr 2007; Coan & Allen 2008).
  • coma
Beta 12 – 30 Hz both sides, symmetrical distribution, most evident frontally; low amplitude waves
  • alert/working
  • active, busy or anxious thinking, active concentration
Gamma 30 – 100 + Somatosensory cortex
  • Displays during cross-modal sensory processing (perception that combines two different senses, such as sound and sight) (Kisley & Cornwell 2006; Kanayama, Sato, & Ohira 2007; Nieuwenhuis, Yeung, & Cohen 2004)
  • Also is shown during short term memory matching of recognized objects, sounds, or tactile sensations (Herrmann, Frund, & Lenz 2009)
  • A decrease in gamma band activity may be associated with cognitive decline, especially when related the theta band; however, this has not been proven for use as a clinical diagnostic measurement yet (Moretti et al. 2009).