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Head measurements and electrode placement according to the 10-20 electrode placement system (Jasper, 1958). The longitudinal line from the nasion to inion is divided into 10% and 20% segments. Distances along the transverse line (dashed) and the circumference (dotted) are not to scale because the 3-dimensional head is drawn in 2-dimensional profile. Approximate locations of Fz, C3, O1, and A1 (behind the ear) are indicated.
