# Visual Perception of Peripheral Screen Elements: The Impact of Text and Background Colors
## 2 Experiment  
The experimental part aims to identify parameters affecting the visual perception of objects in the peripheral screen area while the user focuses on content in the center, as new information or a message appears in the peripheral part. The research aimed to identify, from ten combinations tested, the most noticeable combination of text and background color for the stimulus appearing in the peripheral part of the screen. The measurements were conducted under controlled conditions in a classroom during daylight, using multiple computers with the same configuration. LG 22M45 monitors with a 21.5\" diagonal and a 16:9 aspect ratio were used. The average distance between the subjects and the screen was 70 cm \(\pm\) 5 cm. The target group consisted of students aged 20 to 26 years with a similar education level, involving undergraduate and graduate students from University North, Croatia. A total of 127 participants, including 71 males and 56 females, took part in this study. None had prior experience with this type of testing. The testing included five quizzes, with the stimulus appearing in the peripheral area at the same time for all participants, at the 26 th second. For this research, a web-based application was developed to perform the necessary measurements. Originally built with Adobe Flash, the tool now runs via Ruffle, a secure emulator that supports legacy Flash content in modern browsers. The experimental environment was configured with specially designed XML files. By adjusting these files, researchers could modify specific parameters, such as the direction and speed of changing shapes on the screen. Data from each participant were stored in a MySQL relational database via a custom API, developed with the PHP programming language. Communication between the application and the API used the JSON data format. Later, statistical analysis was performed on the collected data using SQL and standard analytical methods. The mentioned application was tested and used in preliminary measurements to develop a research protocol and study the impact of color and shape on identifying moving objects in the peripheral screen area. The results were published in a scientific article by [PERSON] [23], and based on these findings, a plan for further research was created. In the preliminary phase of this study, three quizzes were administered. The overall duration of the testing was relatively short (20-30 s), which allowed participants to maintain a high level of attention throughout the procedure. In the current phase of this study, the number of quizzes was increased to five in order to collect a larger amount of data. Including the time needed to enter basic personal information and answers, the total duration of the testing was slightly over two minutes. This adjustment made it possible to gather more data without significantly affecting participants' cognitive engagement. The main difference from the preliminary studies was the change in the peripheral screen stimulus. Instead of various shapes, words in two colors (black and white) appeared on five different background colors (black, yellow, red, green, and blue). The purpose of the preliminary measurement was to examine the influence of color and shape on the identification of moving objects in the peripheral part of the screen. Preliminary research findings indicated that the highest percentage of correct responses in the peripheral area of the screen was recorded for triangular shapes (93.96%), whereas the lowest percentage was observed for octagonal shapes (34.88%). These results suggest that more complex geometric forms, particularly those with a higher number of angles, are more difficult to detect in peripheral vision. Regarding the color of the stimuli, the results demonstrated no significant deviations, as all colors yielded a high percentage of correct responses in the peripheral screen area [23]. Based on the processed results of the preliminary measurements, specific modifications were implemented in the application used for subsequent testing.