Inter electrode distance 27 ± 3 mm (given a head circumference of 58 cm).
This montage (Gölz & Rösler, FB Psychologie, Philipps-Universität Marburg) is characterized by near-to-perfect equidistant electrode positions, which were computed from a sphere converged to a realistic head shape This type of electrode arrangement is particularly suited for all interpolating and localizing analysis: brain mapping, dipole analysis and current source densities.
The covered area reaches sagittaly from Fpz to the inion. The outer circle runs through the preauricular points. Positon No. 6 is equal to Cz. The ear area was left blank. Since the total number of 128 channels isn’t used up, other parameter, as EOG, ECG or e.g. from a potentiometer may be acquired as well.
The electrode numbering was chosen for practical reasons. The numbers form a inward bound spiral on each side of the head. Such, electrodes can be mounted by two persons at the same time, without becoming confused.
The grey marked electrode positions constitute a subsample of 32 + 1 equidistant electrodes, which can be used for exploratory purposes or as a montage of its own.
(This montage is also depicted on the first page photograph - there without Ref and Gnd.)