Abstract

Studies of "change blindness" (Simons&Levin, 1997; Rensink et al., 1997) and visio-motor tasks (Hayhoe et al., 1998; Ballard et al., 1998) have revealed that only small part of information in a scene is represented in the visual system at any moment. Attention plays an important role in active and selective nature of vision. But how is attention deployed during performing a natural and complex task, what information is extracted from time-varying images? We examined attentional deployment in driving by comparing detectabilities of a briefly presented STOP sign in the two different contexts, either at an intersection (normal context) or in the middle of a block (unexpected context). Subjects drove through a virtual environment, following another car and observing normal traffic rules. If information must be actively extracted from the image, simple presence of the sign in the scene is not enough to ensure detection. In other words, a STOP sign should not be detected if its presentation does not coincide with an active search episode. On the other hand, if the stimulus itself attracts attention, however, it should be detected whenever it is presented, and there should be no difference in detectability between two contexts.

© 2000 Optical Society of America