THE INFLUENCE OF HYPERPNEA AND OF VARIATIONS OF THE O2- AND CO2-TENSION IN THE INSPIRED AIR UPON AFTER-IMAGES

Abstract

The influence of O2-lack, CO2-excess and hyperpnea is studied in regard to the latent period and appearance of negative after-images in 62 exps. on 8 subjects. It is found that under suitable conditions (O2 conc. 9-11%, CO2 conc. 4-7%, or voluntary hyperpnea lasting 2-5 min. at a rate of 35 and more per min.) there is a lengthening of the latent period of neg. after-images or even complete absence of any after-images. The effect may last as long as 12 min. after the readmission of air. The results correspond to those obtained in a previous paper with audition and seem to point out that O2-lack, CO2-excess and reduction in CO2-tension of the blood due to hyperpnea each cause a lowered excitability of the fundamental nervous mechanism involved in vision.