Do high levels of carbon dioxide impair decision-making performance? According to researchers at the Lawrence Berkeley National Laboratory, the answer appear to be that it does.
A paper titled "Is CO2 an Indoor Pollutant? Higher Levels of CO2 May Diminish Decision Making Performance" documented the results of research on a group of test-takers subjected to different levels of carbon dioxide in an enclosed chamber. The research found that the increasing CO2 levels alone, without any other variables, had a direct impact on the results of tests designed to quantify decision making performance.
In their conclusion, they write:
"The dramatic direct influence of CO2 on decision making performance was unexpected and the study needs to be replicated. The findings of this study, if replicated, have implications for the standards that specify minimum ventilation rates in buildings, and indicate the need to adhere more consistently to the existing standards."