Feasibility study of ability assessment using fNIRS

Significance of the Study

The ability to monitor cognitive workload and performance in professional settings such as aviation is critical for safety and training efficiency. Functional near-infrared spectroscopy (fNIRS) offers a noninvasive means to assess prefrontal cortex activity, providing insights into pilot expertise, workload management, and neural adaptations over years of flight experience.

Objectives and Study Overview

This feasibility study aimed to evaluate whether fNIRS can differentiate brain activity patterns between experienced airline captains and young pilot trainees during simulated aircraft landings of varying difficulty. The analysis focused on the dorsolateral prefrontal cortex (DLPFC) as a key region for executive control and decision-making under task demands. Two groups of pilots performed easy and difficult landing tasks in a certified flight simulator, allowing direct comparison of neural responses and flight performance metrics.

Methodology and Instrumentation

• Subjects: 12 male pilots from an international carrier—6 expert captains (average age 48, ~10,490 flight hours) and 6 trainees (average age 24, ~120 flight hours).
• Task Protocol: Five landing trials per pilot—two easy and three difficult approaches. Each trial included a 2-minute rest baseline followed by a 4-minute landing segment from 2000 to 0 ft altitude.
• Data Acquisition: fNIRS with a 22-channel prefrontal montage. Regions of interest targeted left and right DLPFC based on Brodmann area mapping using a 3D digitizer and NIRS-SPM software.
• Signal Processing: Low-pass filtering at 0.1 Hz, hemodynamic separation, baseline correction to zero at task onset, and computation of oxy-hemoglobin concentration changes between 1500 ft and 500 ft.
• Performance Scoring: Integration of deviations from ideal flight parameters (airspeed, pitch, etc.) within each segment; lower scores indicate better performance.

Instrumentation Details

The study utilized a portable LIGHTNIRS system (22 channels) with type A fiber holders and optional LABNIRS expansion modules (up to 142 channels). A 3D position measurement system and video recording supported precise channel localization and motion correction. These compact systems enable flexible deployment in simulator and field environments.

Results and Discussion

Expert captains outperformed trainees across both task difficulty levels, consistently achieving lower performance deviation scores. Both groups exhibited increased DLPFC activation during difficult versus easy landings, reflecting higher cognitive demand. However, experts showed significantly greater left-hemisphere DLPFC activity compared to the right (p<0.001), a lateralization not present in trainees. While cognitive aging models suggest reduced lateralization in older individuals, the observed left-dominant activation in experienced pilots implies that proficiency rather than age drives asymmetrical engagement of executive control networks. Trainees appeared to recruit bilateral prefrontal resources, potentially reflecting less efficient neural strategies under high-demand conditions.

Benefits and Practical Applications

• Objective Assessment: fNIRS offers a quantitative biomarker of pilot expertise, enabling tailored training protocols and real-time monitoring of cognitive workload.
• Training Optimization: Identification of neural efficiency patterns may guide adaptive simulators that adjust difficulty based on prefrontal activation.
• Safety Enhancement: Continuous brain monitoring during critical flight phases could support early detection of cognitive overload or fatigue.

Future Trends and Opportunities

Advancements in wearable fNIRS technology will further reduce hardware footprint and motion artifacts, facilitating in-cockpit monitoring. Integration with machine learning algorithms may enable predictive models of pilot performance and automated fatigue detection. Expansion to multi-modal measurements (EEG, eye tracking) could enrich cognitive state estimation. Moreover, large-scale normative databases of neural signatures across pilot populations will enhance benchmarking and personalized training strategies.

Conclusion

This study demonstrates the feasibility of using fNIRS to discern expertise-related brain activation patterns in a realistic flight-simulator setting. The lateralized DLPFC engagement observed in veteran captains underscores the potential of fNIRS as a tool for objective assessment of cognitive proficiency in aviation. Further research with larger cohorts and diverse tasks is warranted to validate these findings and translate them into operational pilot support systems.

Reference

1) Kawaguchi K, et al. Heliyon. 2024 Apr 25;10(9):e30242. doi:10.1016/j.heliyon.2024.e30242.