Perceptual information and attentional constraints in visual search of collision events

This study examined the detection of collision events when multiple moving objects were present in the scene. Observers were presented with displays s imulating a 3-D environment with multiple moving objects. The authors exami ned the ability of observers to detect collisions using a signal-detection paradigm and a visual search paradigm. The results indicated that, overall, observers were quite accurate at detecting collisions. Observers used both expansion information and static position to detect collisions, with expan sion information being the more important source. Singleton search conditio ns were not processed in parallel, and conjunction search conditions had po orer performance than singleton search conditions. In addition, reaction ti mes were greater for target-present trials as compared with target-absent t rials. The results are interpreted in terms of 4 visual search hypotheses f or collision detection when multiple moving objects are present.