Cognition, economic decision-making, and physiological response to carbon dioxide

This study examines the isolated effect of carbon dioxide on cognition, economic decision-making, and the physiological response in healthy adults. The experiment took place in an air-tight respiration chamber controlling the environmental conditions. In a single-blind, within-subject study design, 20 healthy participants were exposed to artificially induced carbon dioxide concentrations of 3,000 ppm and 900 ppm in randomized order, with each exposure lasting for 8 h. A high ventilation rate and an air pollutant filter were used to keep concentrations of volatile organic compounds and fine particles equally low in both conditions. Cognition tests were conducted twice during the 8 h and physiological parameters were measured continuously over the 8 h. No evidence on a robust statistically significant effect of carbon dioxide on either cognitive or physiological outcome variables were found. These findings imply that the human body is able to deal with exposure to indoor carbon dioxide concentration of 3,000 ppm for a limited time without suffering significant cognitive decline, changes in decision-making or showing any physiological response.