Brain Network Reorganization in Response to Multilevel Mental Workload in Simulated Flight Tasks

In various real-world situations, inappropriate mental workload (MWL) can impair task performance and may cause operational safety risks. Growing efforts have been made to reveal the underlying neural mechanisms of MWL. However, most studies have been limited to well-controlled cognitive tasks, overlooking the exploration of the underlying neural mechanisms in close-to-real human–machine interaction tasks. Here, we investigated the brain network reorganization in response to MWL in a close-to-real simulated flight task. Specifically, a dual-task (primary flight simulation + secondary auditory choice reaction time task) design flight simulation paradigm to mimic real-flight cognitive challenges was introduced to induce varying levels of MWL. The perceived subjective task difficulty and secondary task performance validated the effectiveness of our experimental design. Moreover, multilevel MWL classification was performed to delve into the changes of functional connectivity (FC) in response to different MWL and achieved satisfactory performance (three levels, accuracy $=$ 71.85%). Further inspection of the discriminative FCs highlighted the importance of frontal and parietal-occipital brain regions in MWL modulation. Additional graph theoretical analysis revealed increased information transfer efficiency across distributed brain regions with the increase of MWL. Overall, our research offers valuable insights into the neural mechanisms underlying MWL, with potential implications for improving safety in aviation contexts.