Study on Situation Awareness under Different Mental Workloads

The aim of the present study was to examine the situation awareness (SA) changes under various mental workloads and to explore the sensitive physiological indicators to SA under this circumstance. Twenty-four participants were recruited to perform tasks under three kinds of mental workload based on the Multi Attribute Task Battery (MATB) Ⅱ platform. Performance measures, situational awareness global assessment technology (SAGAT), three dimensions situation awareness rating technology (3D-SART), eye movement and electroencephalograph (EEG) data were recorded. Results indicated that, the SAGAT scores and 3D-SART scores decreased significantly with the increasing of mental workload. In addition, the two scores both have a medium negative relationship with the National Aeronautics and Space Administration Task Load Index (NASA-TLX) scores. The SAGAT scores have a medium positive relationship with the high alpha relative power at C4 electrode site. What's more, The SAGAT scores have a medium negative relationship with the Nearest Neighbor Index (NNI) under high mental workload condition. In conclusion, under different mental workload levels, (1) Mental workload has a medium negative relationship with SA. (2) NNI and high alpha relative power may be possible sensitive indicators to SA. The present study can provide a reference for designing the display and control interface in cockpit and for optimization of man-machine functional allocation