Brain Activity-Based Metrics for Assessing Learning States in VR under Stress among Firefighters: An Explorative Machine Learning Approach in Neuroergonomics

Air Force Pilot Expertise Assessment with Regard to Mental Effort Requested during Unusual Attitude Recovery Flight Training Simulations

Pilot training and expertise are key aspects in aviation. A traditional way of evaluating pilot expertise is to measure performance output. However, this approach provides a narrow view of the pilot’s capacity, especially with regard to mental and emotional profile. The aim of this study is hence to investigate whether neurophysiological data can be employed as an additional objective measure to assess the expertise of pilots. In this regard, it has been demonstrated that mental effort can be used as an indirect measure of operator expertise and capacity. An increase in mental effort, for instance, can automatically result in a decrease in the remaining capacity of the operator. To better investigate this aspect, we ask two groups of Italian Air Force pilots, experienced (Experts) and unexperienced (Novices), to undergo unusual attitude recovery flight training simulations. Their behavioral (unusual attitude recovery time), subjective (mental effort demand perception) and neurophysiological data (Electroencephalogram, EEG; Electrocardiogram, ECG) are collected during the entire flight simulations. Although the two groups do not exhibit differences in terms of unusual attitude recovery time and mental effort demand perception, the EEG-based mental effort index shows how Novices request significantly higher mental effort during unusual conditions.

Validation of a Light EEG-Based Measure for Real-Time Stress Monitoring during Realistic Driving

Driver’s stress affects decision-making and the probability of risk occurrence, and it is therefore a key factor in road safety. This suggests the need for continuous stress monitoring. This work aims at validating a stress neurophysiological measure—a Neurometric—for out-of-the-lab use obtained from lightweight EEG relying on two wet sensors, in real-time, and without calibration. The Neurometric was tested during a multitasking experiment and validated with a realistic driving simulator. Twenty subjects participated in the experiment, and the resulting stress Neurometric was compared with the Random Forest (RF) model, calibrated by using EEG features and both intra-subject and cross-task approaches. The Neurometric was also compared with a measure based on skin conductance level (SCL), representing one of the physiological parameters investigated in the literature mostly correlated with stress variations. We found that during both multitasking and realistic driving experiments, the Neurometric was able to discriminate between low and high levels of stress with an average Area Under Curve (AUC) value higher than 0.9. Furthermore, the stress Neurometric showed higher AUC and stability than both the SCL measure and the RF calibrated with a cross-task approach. In conclusion, the Neurometric proposed in this work proved to be suitable for out-of-the-lab monitoring of stress levels.