VISUAL PERFORMANCE ON SYNCHRONOUS AND ASYNCHRONOUS PERIPHERAL TARGET DETECTION TASKS

Horizontal visual lobe boundaries were measured for a peripheral targe t detection task using synchronous and asynchronous target presentatio n. The peripheral target was presented either at the beginning or end of stimulus presentation at one of three different target exposure dur ations for asynchronous presentation. Correct responses for the synchr onous presentation were found to be much lower than that for the async hronous one. With asynchronous presentation, exposure duration was imp ortant but not directly related to detection performance. Instead, tim ing of onset or offset of the target during presentation was found to affect detection performance. The results show that it is not appropri ate to generalize the results of visual lobe tests obtained at static condition for visual search tasks containing dynamic content. (C) 1997 John Wiley & Sons, Inc.