0 relating to the mastoid process (= part of the skull just behind the ear):
1 shaped like a breast or a nipple (= one of the two small darker parts that stick out from the breasts or chest)
A grounding electrode was placed on a prepared site over the left mastoid.
A subclavicular ground was used instead of mastoid or earlobe leads since the subjects wore headphones during the recording.
Some of the bone, especially the mastoid process of one adult male, showed evidence of cremation.
Signals were then rereferenced to the left and right mastoid channels and cut into 1,100 ms epochs starting 100 ms before stimulus onset.
The right mastoid was actively recorded and the data were re-referenced to the algebraic sum of the left and the right mastoids off-line.
Recordings were on-line-referenced to the left mastoid and off-line-rereferenced to the average of the two mastoid recordings.
Following cap placement, a small amount of abrasive gel was inserted into each of the electrode sites and the mastoid sites.
All scalp electrodes were referenced to the left mastoid and off-line re-referenced to linked left and right mastoids.