Dependence of the auditory brainstem response on electrode location.

The human auditory brainstem electric response to right ear stimulation was studied for effects dependent on active electrode location. Recordings were made with the reference electrode located on the sternum and the ground electrode located on the nasion. Responses showed significant differences for electrodes that were located at two cephalic (left and right mastoid processes) and three non-cephalic (wrist and left and right sides of the neck) active locations. Components 1 to 6 (Jewett vertex potentials I to VI) were not identifiable at the wrist, but were consistent in polarity for all other (15) locations, apart from the right side of the neck and the right mastoid process, where components 1 and 3 showed polarity reversal. Components 1, 2, 3, and 5 were best recorded with the use of M2--Fz, T4, F4, and Cz locations, respectively. Taking into account all of the components responses were best recorded with the use of the M2--Pz differential electrode pair.