Effects of 7.5% CO 2 -induced anxiety on individual performance

The inhalation of 7.5% CO2 has been shown to induce cognitive effects similar to anxiety. Sixteen healthy participants (14 male; mean age 25.6 years) inhaled either a mixture of 7.5% CO2 gas or air while playing a group combat computer game. Participants reported greater feelings of anxiety and fired fewer bullets when inhaling CO2 compared with air, indicating CO2-induced anxiety may improve efficiency without task-related decrements. Being able to induce controlled and measured anxiety in group situations by CO2 inhalation may be a useful technique when evaluating response to stressful situations, such as combat, in simulators or real-life scenarios.