Abstract
Objective: The aim of this study is to investigate discrimination power of a black letter on the 3 types of color background; red, green and blue colors. Background: In previous studies on visual search, the similarity between distractors and target was main factor to visual search performance. However, there were a few studies on how the background color of visual search field affects visual search performance. Method: In the search fields with black distractors, black target and 3 types of background colors, all of ten subjects were participated in two kinds of experiments. Each subject performed visual search experiments of 50 times for a kind of background color to measure an average time of visual search. Each subject repeated visual lobe experiments of 720 times for one background color and the size of visual lobe was measured using these measurements. Results: The size of visual lobe was not affected by the background color. Visual search time was significantly different when the background color was green and blue. However, when the background color was green and red, and red and blue, the visual search time was not significantly different. Conclusion: The background color effect appeared in visual search time, but not in the size of visual lobe. These results may indicate that there is more background color effect when searching target with sufficient time than when searching target in a short time. Application: The results of this research will be helpful in selecting color background for black letter or black object.