DUSSER de Barenne and McCulloch,1 in 1939, described the phenomenon of cortical suppression following the application of strychnine or electrical stimulation to certain regions of the central cortex. They found after such stimulation a decrease in electrical activities in other areas of the central cortex and also a decrease in the function of the specific areas of the cortex. Somewhat similar phenomena have been described in the various forms of extinction and of spreading depressions of Leão.2 Dusser de Barenne, Garol, and McCulloch3 described particular areas of the cortex from which the suppression response could be elicited. They originally described Areas 4s, 2s, 8s, and 19s, and, later, Area 24, on the medial aspect of the hemisphere. But there has been some disagreement with their views. Marshall and Essig4 maintained that the suppressor areas do not exist as such and that Dusser de Barenne and McCulloch