On the origin of the EEG alpha rhythm.

at posterior cerebral locations which are not grossly pathological (Jasper, 1949; Penfield & Jasper, 1954). The alpha rhythm under these conditions is of larger amplitude than the alpha rhythm of EEG obtained through scalp leads. This difference in amplitude reflects shunting by these surroundings of the skull. All electrocortical activity suffers shunting by the intact CSF, dura, and brain to the same extent. Whether the brain pulsates mechanically or not makes no difference in the waveform of the alpha rhythm. The possible artifact in electroencephalography which Kennedy's model implies therefore seems nonexistent. REFERENCES