An electrode placement system has a headband that is adjustable for size two or more retainers slidably mounted on the headband and a first elastic measurement cord, wherein the cord is releasably held by the two or more retainers in order to determine a position on a cranium. An electrode retention system has a headband that is adjustable for size, having a plurality of attachment points thereon, two or more strips, each strip having two ends, wherein each strip is connected to an attachment point at one end, and at least one adjustable electrode holder configured to hold an electrode to a cranium, wherein first and second strips are connected to attachment points, and first and second strips pass through the electrode holder, and are independently retained by the adjustable electrode holder such that the electrode holder is adjustable for tension and position.
