Examining the Utility of Blink Rate as a Proxy for Cognitive Load in Flight Simulation

Blink rate has been suggested to be a proxy for cognitive load. However, there are mixed results regarding this association, which is modulated by the visual demand of a task or when a dual-task paradigm is performed. This study investigated blink rate as a measure of cognitive load using a dual task paradigm (i.e., primary task = flying an aircraft; secondary task = auditory oddball task) to specifically assess changes in cognitive load across two flight phases (i.e., cruise, landing). Primary task performance suggested participants focused on maintaining aircraft control across task conditions, but a significant dual-task difference score in auditory oddball task performance (p<0.001) was still evident across flight phases. Blink rate did not show similar differences across flight phases. Our results demonstrate that the utility in using blink rate to measure cognitive load may be limited in its application to more complex naturalistic scenarios when using an auditory dual-task.