Abstract
It was investigated how several properties of oval shape influence visual search process. We used oval stimuli as distracters and targets in visual search paradigm and performed three experiments. In experiment 1, we manipulated ratios of major to minor axes so that there were three ratios; 1:4, 2:4, and 3:4. It was conjectured that gradual changes of oval axes ratio influenced visual search process systematically. We found that there was no set size effect of ratio 1:4, whereas significant set size effect of ratio 3:4. Slopes of searching time changed systematically according to the ratios of major to minor axes. In experiment 2, we used concave and convex shapes of oval as distracters and targets. We conjectured that there existed search asymmetry because convex distracters might be organized more easily as background than concave distracters, and observed the proposed result. In experiment 3, we manipulated directional axes and convexity/concavity of oval shape. We found that the easiest search condition was a search of vertical convex target against horizontal convex oval distracters. It took more time to search a horizontal target than a vertical target. These results implied that grouping process are influenced by directions of oval object asymmetrically. Furthermore, concavity and convexity of objects also influence grouping process so that efficiency of visual search was changed. It is suggested that the familarity of visual environment makes efficiency of grouping process of these elements asymmetrically.
Supported by Korea BrainTech 21