# Review of Studies on User Research Based on EEG and Eye Tracking
## 5 Discussion
### Future Research Prospects  
#### 5.3.1 Multisensory and Behavioral Interaction Research  
From the literature review, it can be seen that current user research in industrial products, digital interfaces, and spatial environments mostly focuses on visual and cognitive brain research. However, since the user experience is affected by aspects such as shape, smell, and touch, multi-sensory and behavioral interaction research should be given more attention in the future. In interface interactions, the drop-down method of lists, the animation's form, the feedback text, the color information, and the sounds should all be considered as a whole. Using EEG and eye tracking equipment, reasonable experimental designs can be used to study the interactions between the five senses and cognitive behavior, such as audio-visual, audio-taste, visual-taste, touch, smell, and other sensory interactions. For example, some studies have found that smoothness, softness, and sphericity are associated with higher brightness and chroma [103; 104]; geometric shapes in vision will affect people's taste information processing process. The influence of different shapes on taste evaluation intensity (intensity) and efficacy (potency) has been widely confirmed [105], especially the relationship between shape polysemy and perceived efficacy. In addition to shape, visual color also affects taste perception. Research has shown that compared to green and white light, consumers give higher ratings when drinking red wine under blue and red light, and are also willing to pay more. Blue and green light makes people feel that the spicy and fruity flavors of red wine are heavier, while red light makes people feel that red wine is sweeter [106]. Moreover, environmental sensory stimulation should also match the product category attributes. For example, in a dining environment, all sensory factors in the restaurant should be included in the scope of customer taste management. Not only should the shape, color, and touch clues of containers such as plates, spoons, and wine glasses be considered for their impact on consumers' taste perception, but also the interactions between background lighting and odor with consumers' taste perception [107].  
The interaction between sensations is one of the current hot research topics. Previous multi-sensory interaction research has mostly focused on the fields of biology and psychology. In practical applications, people's feelings about products are often integrated and semantic. Current user research ignores individual differences in multi-sensory interactions and needs to be further explored in future research. In addition, some previous research data have shown that there are differences in the performance of different subjects in multi-sensory interactions under the same cultural background [108], but there has been no in-depth discussion of this issue. For example, why some people are more likely to have multi-sensory interactions than others can be studied, and future research can also analyze the root cause of this phenomenon from the perspective of differences in thinking.