Electroencephalographic phase reversal observed in chickens.

OOKAWA and GoTOH8,9,10)have studied the surface electroencephalogram (EEG)of chickens by the chronic experimental method and determined its normal patterns from wakefulness to sleeping and the effect of anesthesia on EEG. In their experiments,electric activity revealed many interesting characters, including phase reversals at certain regions of the brain. The phase reversal mentioned above,was originally observed in the examination of a series of leads on the surface of the skull,including the frontal and parietal regions,for relative polarity. Owing to the dipole hypothesis concerning the EEG origination,it was suggested from this examination that further attempts might possibly determine the site and role of the dipole as the origin of EEG. In the present experiment,analysis was made on the electric field concerning the phase reversal by using the bipolar leads of chronically implanted electrodes.