## 2 Literature Review  
### Visual Attention for Food  
Vision is the most used sense during the process of buying food [9,10] because consumers need to visualize information before they can use it in the selection process [11]. Visual attention broadly represents the cognitive process of understanding specific visual information and demarcating these into areas of interest (AOI) [12, 13, 14, 15]. Visual attention is understood to be the first stage of a series of processes that influence consumer choice [16]. The attention given by consumers to a stimulus is selective and can be presented in the following two ways: bottom-up, in which attention is directed to stimuli, and top-down, which is related to the objectives of the observer [17,18]. The bottom-up situation occurs when a stimulus stands out in the visual field, that is, attention is guided by visual characteristics, such as the size, color, and shape of a stimulus or internal characteristics of stimuli that automatically capture the attention of individuals [19, 20, 21, 22]. Researchers have explored how the appearance of cereal bars influences the consumer purchasing decisions across different brands and flavors [13]. They found that brand and variety were key determinants in driving consumer attention, suggesting that greater attention given to a brand increases the likelihood of its selection. Another study evaluated the effect of visual attention on product labels on chocolates, yoghurt, and tomato with the organic symbol in different sizes [23]. They found that the use of bottom-up effects to improve the design and visibility of this information increased attention capture as well as the probability of product choice. Conversely, top-down attention occurs when consumers focus on stimuli that are in line with their goals, expectations, and even their emotions [19,24,25,26]. Research has observed that consumers perceive the healthiness of mayonnaise, bread, and yoghurt, as well as their willingness to buy, and found that consumers directed visual attention to specific information such as ingredients and nutritional information [27]. The effect of beef fat content on visual attention and purchase choice has also been examined, with researchers finding that consumers pay more attention and more often choose beef with a lower fat content due to the perception of healthiness [28]. Specific objectives can focus on visual attention and food choice [29]. When observing a stimulus, the consumer's eye movements can be measured with eye-tracking equipment, which allows accurate recording of periods and fixation sites. The literature suggests that consumers process AOI information with fixations on specific attributes. Alternations between these fixations, e.g., color and size, are called saccades. Fixations are the periods of attention given to an area of interest, characterized by periods of discrete immobility of the eye while the information is visualized and processed before looking for another AOI. Although it is understood that the view is suppressed during the saccades, they are useful to reveal elements of the consumer's visual search, such as trade-offs and the order seen in the AOI [18; 30; 31]. In the present study, the AOIs contemplate information on quality and visual cues based on the color, marbling, breed, flavor, tenderness, and aroma of beef. The main parameters of visual attention contemplated in the present study include the following: (1) time of the first fixation--reflects the time it takes the consumer to process information of an AOI for the first time. In general, information that is more complex for the consumer takes longer to be visualized, so the shorter the time for the first fixation, the greater the ability of information to capture visual attention. (2) The total fixation time--indicates the total time of fixing on an AOI throughout the stimulus. Long fixations may indicate that the consumer has difficulty in interpreting the information presented.