## 2 Methods
### Experimental Design  
#### 2.3.1 Cognitive Load Test  
(a) Experimental principles  
The amount of time pressure usually influences the cognitive load of a person. This experiment referred to the time pressure setting in [PERSON]'s experiment and made experiments and adjustments based on it. In this experiment, time pressure was defined as either high, medium, or low time, corresponding to time limits of 2000 ms, 4000 ms, and no time limit. Participants were instructed to respond as fast and accurately as possible to determine the effect of time pressure on cognitive load based on participants' performance across the three conditions. (b) Experimental materials  
Figure 1 illustrates the 16 icons (.png format, resolution 128 \(\times\) 128 pixels) designed for this experiment, representing four different smartphone interface base icons (weather, time, file, and homepage) and their respective up-down, left-right, up-down, and left-right flip states. To mitigate the influence of other factors, all the icons in this experiment were de-colored, and shape factors, such as icon composition, were kept constant. (c) Experimental Procedures  
This experiment comprised a visual search task. Prior to the start of the experiment, subjects were instructed to familiarize themselves with the semantic meanings of the relevant icons and then underwent 16 unrecorded training experiments (the training experiments could be repeated if subjects felt they had not fully mastered them). Following the training phase, each subject was required to complete three rounds (high, medium, and low time pressures) of the formal experiment for a total of 240 sessions (16 \(\times\) 5 \(\times\) 3). The order of the experimental rounds remained consistent, and participants performed the three rounds in the order of high-moderate-low time pressure. Upon completion of each round, the participants were asked to complete the NASA-TLX CognitiveFigure 1: All icons used in the cognitive load test. At the beginning of each experiment, an attention point was presented at the center of the screen for 500 ms, followed by the appearance of a random target icon at the location of the attention point for 1000 ms. Participants were instructed to memorize the shape, front, and back views, and other design features of the target icon. After the icon was presented, the gaze point reappeared for 500 ms, after which participants were required to identify the target icon among the 16 alternatives (including 15 distractor icons and 1 target icon) that appeared on the screen and move the cursor to click on the target icon. The arrangement of icons was based on the method used in [PERSON]’s study, i.e., the 16 icons were evenly distributed around the center of the screen in a circular stimulus array, and their order and position were determined by a random number generated by the pseudo-random algorithm. Participants were instructed to make their choices within the designated time frame. In order to strengthen the sense of time pressure, a countdown timer was placed in the upper left corner of the screen, displaying either 2 s, 4 s, or no countdown, accompanied by a clock ticking sound. After participants made their choice, the icon and the countdown disappeared, and the ticking sound ceased. The screen provided feedback on the correctness of the choice, response time, and average accuracy rate for the round. Upon completion of all 80 search tasks in the round, participants proceeded to the next round, starting with another set of 80 search tasks under either medium or low time pressure conditions. The flowchart of this experiment is illustrated in Figure 2.  
Figure 2: Example of the experimental flowchart for each round. Experimental reference indicators  
The NASA-TLX scale filled out by the participants after each round was used as a reference index in this experiment. The scale was adapted according to the characteristics of this experiment and encompassed four dimensions, namely, cerebral demand, effort procedure, time demand, and degree of frustration.