Effects of Hyper-and Hypoventilation upon EEG Pattern

　Sir，──There has been considerable accumulation of works on the effects of changing respiratory gas contents upon EEG pattern．Interpretation of the results of these works, however, varies rather widely from one investigator to the other．This paper describes a study into the mech．anism involved in the alteration in EEG pattern produced by hyper- and hypoventilation with room air．

　Electroencephalograms were taken in cats, weighing 2 to 3kg, immobilized with d-tubocurarine chloride and under artificial positive pressure respiration with room air．