The role of respiratory measures to assess mental load in pilot selection.

While cardiovascular measures have a long tradition of being used to determine operator load, responsiveness of the respiratory system to mental load has rarely been investigated. In this study, we assessed basic and variability measures of respiration rate (RR), partial pressure of end-tidal carbon dioxide (petCO2) as well as performance measures in 63 male pilot candidates during completion of a complex cognitive task and subsequent recovery. Mental load was associated with an increase in RR and a decrease in respiratory variability. A significant decrease was also found for petCO2. RR and respiratory variability showed partial and complete effects of recovery, respectively, whereas petCO2 did not return to baseline level. Overall, a good performance was related to a stronger reactivity in RR. Our findings suggest that respiratory parameters would be a useful supplement to common measures for the assessment of mental load in pilot selection. Practitioner Summary: Respiratory measures are a promising yet poorly investigated approach to monitor operator load. For pilot selection, we assessed respiration in response to multitasking in 63 candidates. Task-related changes as well as covariation with performance strongly support the consideration of respiratory parameters when evaluating reactivity to mental load.