Although demographic data are limited on the number of accidents that have occurred while a driver used a cellular phone, the data that are available suggest that cellular phone use while driving increases accident risk. This article reports on two experiments undertaken to investigate one factor that might account for an increase in crash risk with in-car phone use: a reduction in the functional field of view. In the two between-subjects experiments, college undergraduates performed a task designed to measure the functional field of view in isolation and while performing a hands-free conversational task. Performance on the task (a visual search for a target across a large region of visual space), with and without a conversational task, provides a metric of the impact of conversation on the spatial extent of attention or the function field of view. In both experiments, the addition of the conversational task led to large reductions in the functional field of view. The authors conclude that, because similar reductions have been shown to increase crash risk, reductions in the functional field of view by conversation may be an important mechanism involved in increased risk for crashes with in-car phone use.
Abstract