The ability to note behaviorally meaningful objects and events in one's visual surroundings is vital to a vehicle operator's ability to maintain optimum performance in a complex environment. This article reports on a set of studies undertaken to examine the effects of cognitive distraction (i.e., conversation) on visual scanning and change detection in natural traffic scenes. The first experiment found that a naturalistic, hands-free phone conversation could disrupt change detection, which resulted in a degradation of the encoding of visual information and an increase in the frequency of undetected changes. This experiment also showed a tendency for conversation to impair the knowledge-driven orienting of attention in older adults. The second experiment showed that an attentive listening task (a series of tape-recorded conversations) resulted in no such effects. The authors conclude with a discussion of oculomotor scanning and visual encoding, and the impact of age-related changes.
Abstract