Who's in the Back Seat? A Study of Driver Inattention

Abstract

Objects that are readily detectable and visible are not always noticed. Demonstrating the difficulty of detecting objects in a scene to people who are already expecting to see them and are aware of the objects' presence poses a challenge. In the following study, two conspicuous objects were placed in the back seat of a sport utility vehicle (SUV). The study parameters were selected in an attempt to replicate a situation involved in a criminal investigation, to test the hypothesis that drivers routinely check the back seat of the car before driving away, and to determine the likelihood of drivers noticing what would seem to be a salient set of objects in the rear seat. Two child-sized mannequins were placed in a prone position on the back seat of a large SUV. Naïve subjects were asked to get in and drive the SUV 1.6 miles around a closed track at night. Twentyseven out of 30 participants failed to notice the mannequins in the vehicle. Visual performance limitations, environmental expectations and "inattentional blindness" effects can account for the results and are discussed in this paper.