## 2 Materials and Methods
### Apparatus  
This experiment utilized a range of equipment, including a flight simulator, a desktop computer with MATLAB, Simulink models, and Xplane software, as well as a Tobii Glasses-2 eye tracker. The flight simulator provided a simulated flight environment, while the desktop computer controlled the simulation using MATLAB, Simulink models, and Xplane software. The Tobii Glasses-2 eye tracker, along with a laptop computer running Tobii Pro Glasses Controller and Tobii Pro Lab software, was used to track and analyze participants' eye movements. The experiment also included a computer host and audio equipment, among other auxiliary devices. The exterior of the flight simulator was designed in a semi-circular shape, resembling the cockpit of an aircraft. These devices were crucial for creating an immersive flight simulation and collecting eye-tracking data for the purpose of examining participants' performance and behavior during the experiment. The flight simulator used in this experiment is shown in Figure 1a. It had three degrees of freedom: pitch, roll, and yaw. It consisted of a pilot seat supported by hydraulic rods and a hydraulic drive unit. Additionally, there was a set of control devices including a control stick, throttle, and pedals, which were used for flight operation inputs. The control system of the flight simulator was designed to mimic the 737-800 aircraft, with the use of fly-by-wire flight control systems for the control stick, throttle control, and pedals to provide flight operation commands. During the experiment, the participant's control commands were transmitted to the computer-controlled simulation model through the control stick, throttle, and pedals to calculate the current flight attitude. Different hydraulic-driven rods were used to control the angle of the central pilot's seat, thereby simulating the three degrees of freedom of pitch, roll, and yaw. The control stick was equipped with buttons and toggle switches for additional functions. By using the set of control devices, participants were able to simulate various stages of flight operations, including takeoff, cruise, descent, and landing. They could also use the troubleshooting button on the control stick to resolve failures. The simulator was equipped with four environment display monitors with a resolution of 1920 \(\times\) 1080 pixels, providing visual information for the simulated flight environment. Figure 1b illustrates the simulated pilot's perspective and the corresponding visual scene. The display system consisted of three circular monitors positioned at eye level to simulate the external view, and one flat monitor tilted at a 45-degree angle below eye level to simulate instrument parameters. These monitors provided visual information to the pilot. The basic flight parameters were shown on the flat monitor (see Figure 1c). The left side of the flat monitor displayed flight instruments and malfunction indicators, including an airspeed indicator, attitude indicator, and altimeter. The bottom of the flat monitor displayed malfunction indicators. On the right side of the flat monitor, there was a parameter curve area that shows key parameters during the flight and parameters required for troubleshooting. Examples of the former include angle of attack, pitch angle, throttle, and brake positions, while examples of the latter include stabilizer position, elevator command, and rudder command. Figure 1d illustrates an example of the parameters' values displayed on the parameter curve area during the flight in the experiment. The participants were able to observe the real-time display of these flight parameters during the flight. The eye-tracking device used in this experiment was the Tobii Glasses-2 (refer to Figure 2), developed by Tobii, a Swedish company. It was a head-mounted, non-invasive eye-tracking device that utilized four cameras (two per eye) with a sampling rate of 100 Hz, as well as an ultra-wide-angle scene camera for eye-tracking.