1. The nystagmic reaction to caloric stimulation under the influence of alcohol, increased CO2 tension and decreased CO2 tension has been studied in schizophrenic and normal persons.2. Under these experimental conditions, the schizophrenic patients showed an apparently paradoxical reaction.a. Under the influence of alcohol the normals showed an increase, the patients a decrease in the number and frequency of nystagmus.b. CO2 depresses the nystagmic reaction in normals. In 40 per cent of the patients, CO2, causes an increased reaction; 45 per cent show no change and 15 per cent behave somewhat similarly to the normals.c. Hyperpnea causes an increase in the normals and a decrease in the patients.Abstract Teaser