The effect of cellular telephone conversation and music listening on response time in braking

Driver distraction contributes to vehicle accidents, with estimates as high as one-half of crashes being distraction-related. The purpose of this experiment was to explore potential distractions by testing the effects of cellular telephone conversation and music listening on response time and its subcomponents of reaction time (RT) and movement time (MT) in a simulated braking task. Participants (N = 27) sat at a simulated driving station and released the accelerator and depressed the brake pedal as quickly as possible following activation of a simulated brake lamp. The braking task was performed under each of six conditions including: (a) the control (braking task only); (b) music playing at 66 dBA; (c) music playing at 78 dBA; (d) cellular telephone conversation; (e) cellular telephone conversation and music at 66 dBA; and (f) cellular telephone conversation and music at 78 dBA. Cellular telephone conversation slowed response time, yet music had no effect on response time. While the RT results generally mirrored those of response time (i.e., RT was also slowed by the telephone conversation), interestingly, MT was actually faster when the cellular telephone conversation was present compared to when it was not. Participants appear to have anticipated slower RT in the presence of the cellular telephone conversation, and attempted to compensate by executing a more rapid movement to the brake pedal.