Effects of-object size and inter-object spacing on peripheral object detection

This paper reports a study on the effect of object size and inter-object space on the detection of peripheral visual objects on a visual display. Three different types of stimuli with small, medium, and large object sizes but constant number of objects were tested. Such a design resulted in smaller inter-object spaces for the large object stimuli. The results were compared to those from a previous experiment by the authors in which both object size and inter-object space were scaled simultaneously. It was found that, for the range of target sizes and eccentricities tested here, using larger objects facilitated object detection during brief stimulus presentation. However, the beneficial effect of magnification of object size on detection performance appeared to be offset by lateral interference at greater eccentricities. This offset of performance by lateral interference was not found when the inter-object space was also appropriately scaled for the type of stimuli used before. The result here showed the importance of selecting appropriate inter-object space as well as object size for a display designed to facilitate the visual search process. Relevance to industry The results of this study have significant implications for the design and determination of dimensions for display contents in visual search tasks by equalising conspicuity of visual information with appropriate scaling based on consideration of cortical magnification. (C) 2000 Elsevier Science B.V. All rights reserved.