# Product Styling Cognition Based on Kansei Engineering Theory and Implicit Measurement
## 4 Results  
### EEG Signals  
The EEG data were processed before determining the experimental results. The main processing steps were re-referencing, ocular correction [52], raw data inspection, filtering, segmentation [53], baseline correction, and superposition averaging [54]. The default reference electrode for the BP EEG device was located at the tip of the nose (FCz). However, in practice, the average value of the bicolor mastoid (TP9, TP10) was used as the reference electrode, a process known as re-referencing. The EEG-evoked potentials during the experiment were extremely weak and easily influenced by disturbances such as blinking, muscle activities, and heartbeat. Ocular correction was applied to mitigate the electromyographic effects resulting from eye movements or blinks. The raw data inspection step aimed to remove artifacts that arose either from the equipment or the movements of the participants. This step comprised settings that accounted for gradient changes between two sampling points, maximum absolute value of amplitude changes, maximum and minimum permissible voltage values, minimum permissible amplitude change within the set time period, and maximum permissible amplitude change within the set time period. Due to the susceptibility of EEG signals to noise, certain frequencies improbable for human generation were filtered. Considering the lowest and highest EEG signal frequencies of the brain, data in this experiment were processed using low-cutoff filtering (0.01 Hz), high-cutoff filtering (35 Hz), and notch filtering (50 Hz) to filter out interference signals. In this experiment, evoked potentials are EEG signal amplitude variations occurring over a period after the participant observes the product study sample. Segmentation was conducted based on the markers of events, and considering the cognitive process of the brain, this experiment was segmented according to the time range from \(-200\) ms to \(800\) ms of the stimulus material presentation [55]. For each study sample, the pertinent EEG data spanned a timeframe of 1000 ms, beginning 200 ms prior to and ending 800 ms after sample presentation. Baseline correction was employed to counteract the effects of data drift on results. Typically, in EEG studies, pre-stimulus EEG activity serves as the baseline. By contrasting it with post-stimulus EEG activity, the EEG signals elicited by the stimulus can be analyzed. For instance, using the \(-200\) ms to \(800\) ms EEG data, the segment from \(-200\) ms to \(0\) ms functions as the baseline, with EEG data fluctuations from \(0\) ms to \(800\) ms being the focus of the study. To enhance both experimental precision and the quality of EEG signal analysis, multiple trials of either the same sample or samples  
Figure 5: Scene of the combined EEG and eye-tracking experiments. of the same type were superimposed and then averaged [56]. Superimposing EEG data not only counteracts spontaneous potentials but also improves the evoked potential EEG signal's analytical quality. Crucially, when superimposing EEG data, time-locking must be observed. Specifically, only EEG signals from identical timeframes across different trials of either the same or similar study samples by the same participant can be superimposed. The divisor in the EEG signal average was consistent with the number of trials presented for the study sample during segmentation. The EEG topography generated using the participant EEG data is depicted in Figure 6. This was derived from the \(-200\) ms to \(800\) ms range of stimulus presentation through the superimposed averaging of EEG signals. As shown in Figure 6, the energy intensity in users' car styling cognition is notably higher in the frontal region, indicating that the frontal region predominantly governs product styling image cognition. According to the 10-20 system for electrode distribution, the electrodes with the highest energy during the combined EEG and eye-tracking product styling cognition experiment were FP1, FP2, F7, and FT9.