What is impedance in EEG?

: A measure of the impediment to the flow of direct current, measured in ohms. Larger numbers mean good contact.

;  A measure of the impediment to the flow of alternating current, measured in ohms. Larger numbers mean higher resistance to current flow. 

; A measure of the connectivity between electrode and scalp, measured in bits. Smaller numbers mean higher resistance to brainwave activity.

; A direct measure of how much paste and abrasive scrub was used to prep the individual. Smaller numbers mean poor contact.

