Abstract
The objective of this study was to investigate the effects of cognitive and visual driver distraction on reaction time to unexpected road hazards. Participants operated a driving simulator while intermittently answering prerecorded questions of varying difficulty (simulating a conversation) or dialing specific numbers into a cellular telephone. Two different road hazards were each presented at unpredictable times and locations, including red brake lights and a red pedestrian-shape of approximately the same area as the brake lights. Stimuli were presented in one of two different locations: directly in front of the driver at the bottom of the screen, or off to the side of the road. The results showed a significant overall increase in reaction time for older subjects, as well as a strong interaction with the dialing task condition. There were no significant differences from the control for either of the verbal response conditions. In addition, participants took significantly longer to respond to stimuli on the side of the road, especially when they were presented in conjunction with the dialing task. These data suggest a strong link between age, visual task load, stimulus location, and increased reaction time to unexpected stimuli.
Thanks to: Franklin & Marshall Psychology Department Shand Fund and the Franklin & Marshall Committee on Grants for project funding.