# Review of Studies on User Research Based on EEG and Eye Tracking
## 4 Application Scope
### Industrial Products
#### 4.1.2 Appearance Form  
The significance of appearance design research is to clarify users' aesthetic preferences and provide design information for product styling optimization. It is worth noting that in recent years, the use of brainwave and eye-tracking technology in the study of chairs has been particularly active due to the closeness of human activities. [PERSON] et al. [51] conducted eye-tracking experiments on Chinese-style chairs, and the results showed that the styling elements that guide the cognitive recognition of styling features were in order of importance of backrest, seat cushion, and armrests, which provided key design elements for the design of new Chinese-style chairs.  
[PERSON] et al. [7] even elevated user preferences for products to the level of aesthetic formula principles. By analyzing output data from eye-tracking software, including gaze count, duration, and coordinates, they explored the mathematical laws of aesthetic quality in product design. Figure 9 provides examples of aesthetic calculation methods for eye-tracking data of different chairs. The experimental results in Figure 10 demonstrate that users' predicted and actual visual performance show a close matching relationship between applicability (left) and novelty (right). In [PERSON] et al.'s [52] experiments on multiple car seat styling samples, the eye-tracking trajectories of the subjects revealed regularity from left to right, and from top to bottom. Results showed that users had a higher aesthetic preference for car seats with horizontal and moderately complex stitching lines. These findings have strategic implications for designing user-preferred car seats. [PERSON] et al. [53] utilized event-related potentials (ERPs) as a method to examine the neural responses linked to users' exploration of diverse product configurations. The findings revealed that images with the ability to evoke participants' intention for deeper engagement resulted in amplified N300 and LPP responses within the central parietal and parieto-occipital regions. This examination of the neural correlates associated with behavioral intention presents a precise measurement approach to accurately assess users' perception. The utilization of these conceptual approaches and methodologies holds significant importance in the validation, assessment, and enhancement of product innovativeness, which provides valuable insights into the effectiveness of innovative product designs, and can facilitate informed decision-making and potential optimization strategies.  
Figure 9: The images which were used in the task [7].  
In packaging-related research, eye-tracking experiment results have shown that the scanning paths of most users are predictable [35], and users tend to associate product styling and its elements with different sensory stimuli, such as the color and flavor of food or drink. [PERSON] et al.'s [54] eye-tracking experiments showed that participants may rely on color when searching for packaging labeled with a certain taste, and if the target cannot be found through color-based search, they switch back to a word-based search. These findings demonstrate the importance of color and taste consistency in packaging design for users.