Effects of 7.5% CO₂-induced anxiety on individual performance: During a group computer combat game

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.