This study concluded that talking on a hands-free phone can be just as distracting for a driver as a hand-held mobile. The research shows that drivers who are engaged in conversations that spark their visual imagination are much less able to spot and react to potential hazards. The study also concluded that when asked about a subject that required them to visualise it, participants focussed on a smaller area of the road ahead and failed to see hazards, even when they looked directly at them. The researchers suggest this shows conversations may use more of the brain’s visual processing resources than previously understood. They suggest that having a conversation which requires a driver to use their visual imagination creates competition for the brain’s processing capacity. As a result, they conclude that drivers miss road hazards that they might otherwise have spotted. Methodology The effects of imagery-induced distraction on hazard perception and eye movements were investigated in two simulated driving experiments. Experiment 1: 60 participants viewed and responded to 2 driving films containing hazards. Group 1 completed the task without distraction; group 2 completed a concurrent imagery inducing telephone task; group 3 completed a non imagery inducing telephone task. Experiment 2: eye-tracking data were collected from 46 participants while they reacted to hazards presented in 16 films of driving scenes. 8 films contained hazards presented in either central or peripheral vision and 8 contained no hazards. Half of the participants performed a concurrent imagery-inducing task. Results Compared to undistracted participants, dual-taskers were slower to respond to hazards; detected fewer hazards; committed more “looked but failed to see” errors; and demonstrated “visual tunnelling”. Telephone conversations may interfere with driving performance because the two tasks compete for similar processing resources, due to the imagery-evoking aspects of phone use.
The study was conducted by the University of Sussex