Table 1 . Cerebral Functions Related to Different EEG Frequencies (8, 9) .

Band	Frequency (Hz)	Location	Normally	Pathologically
Delta	< 4	Frontally in adults, posteriorly in children; high-amplitude waves	• Adult slow-wave sleep • In babies • Has been found during some continuous- attention tasks	• Subcortical lesions • Diffuse lesions • Metabolic encephalopathy hydrocephalus • Deep midline lesions
Theta	4 – 7	Found in locations not related to task at hand	• Higher in young children • Drowsiness in adults and teens • 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).	• Focal subcortical lesions • metabolic encephalopathy • Deep midline disorders • Some instances of hydrocephalus
Alpha	8 – 15	Posterior regions of the 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.	• Coma
Beta	16 – 31	Both sides, Symmetrical Distribution, most evident frontally; low-amplitude waves	• Range span: active calm -> intense - > stressed -> mild obsessive • Active thinking, focus, hi alert, anxious	• Benzodiazepines • Dup15q syndrome
Gam ma	32 +	Somatosensory cortex	• Displays during cross-modal sensory processing (perception that combines 2 different senses such as sound and sight) • Also, it is shown during short-term memory matching of recognized objects, sounds, or tactile sensations	• A decrease in gamma-band activity may be associated with cognitive decline, especially when related to the theta band; however, this has not been proven for use as a clinical diagnostic measurement
Mu	8 – 12	Sensorimotor cortex	• Shows rest-state motor neurons.	• Mu suppression could indicate that motor mirror neurons are working. Deficits in Mu suppression, and thus in mirror neurons, might play a role in autism.