## 3 Material and Methods
### Research Instruments
#### 3.3.4 Real-Time EEG Monitoring System  
This study used the MindWave EEG headset developed by NeuroSky as the experimental instrument and combined it with a self-developed and patented real-time EEG monitoring system to obtain EEG data [47]. Once the headset had been successfully paired with the computer and had been properly donned by the participant, the EEG signal measurement was ready to start. The measured data in the headset were sent to the computer wirelessly through Bluetooth. The data were updated approximately once every second, and the updated data were immediately displayed on the program window on the computer screen. The EEG monitoring system displayed real-time alpha, beta, theta, and delta waves detected by the headset so that the research team could observe the experimental data of brainwave movement and obtain numerical values for variables such as attention, and relaxation parameters.  
Before the real-time EEG monitoring system was turned on, the EEG headset was paired up with the computer. After the port value corresponding to the headset was confirmed, data collection began when the \"Start\" button was pressed. A brief waiting period followed while the headset was connecting to the system. Once the headset had paired with the system, the start menu was displayed on the screen. Once the user had clicked \"OK\" on the start menu, the EEG monitoring system began its monitoring process. The user was able to view the EEG data on the system menu while the monitoring system was running. Figure 3 illustrates that the top portion of the system screen displayed a line graph of the user's stress and energy indices while the bottom portion displayed a bar chart of various EEG band data. The screen refreshed once every second to monitor the user. In the top half of Figure 3, the line graph of stress and energy indices are displayed to enable comparison at each time point,  
Figure 2: Screenshot of animations on graphic symbol vocabulary.  
whereas the bottom half displays real-time numerical changes of eight EEG bands. However, theta, low alpha, high alpha, low beta, high beta, low gamma, and high gamma.  
The brainwave data detected from the MindWave headset consisted of eight EEG bands. However, because copious volumes of data were collected, the meanings of these brainwave data were difficult to understand without organization and analysis. Figure 4 illustrates the raw data measured by the monitoring system. The monitoring system converted raw data to an intuitive line chart and a bar chart, as shown in Figure 3. The researcher had to ensure that the MindWave EEG headset was worn on the participant's head properly once the real-time monitoring system had begun its recording. Subsequently, both the line chart and the bar chart appeared on the pretest and posttest monitoring screen. The three lines on the line chart on the top half of the screen comprised attention, stress, and relaxation parameters. Table 3 illustrates the frequency range of each EEG band. Recorded EEG raw data were filtered into different brainwaves. Before performing statistical analysis, the brainwave powers were subjected to a natural logarithm to make the distribution close to normality.  
Figure 4: Screenshot of raw data in real-time EEG monitoring system.  
Figure 3: Screenshot of the real-time electroencephalogram (EEG) monitoring system.