Abstract
The ability to manage competing tasks has grown increasingly important as modern technologies, such as cell phones, have become pervasive. In two experiments, we characterized the dual-task costs associated with crossing a street while conversing on a cell phone, listening to music over headphones, or undistracted. The task was constructed in an immersive virtual reality CAVE with an integrated treadmill that allowed participants to traverse the simulated environment by walking. In Experiment 1, college-age adults performed crossings under very challenging crossing conditions. Participants were less likely to successfully complete a crossing when conversing on a cell phone (80% success rate) as compared to when listening to music (84%) or undistracted (84%). In Experiment 2, we examined age-related differences (adults age 65 and older compared to college age adults) in the same task, but under easier crossing conditions. Because gait control requires greater attentional control in older adults than in younger adults, we expected that dual-task street-crossing costs would be larger for older than for younger participants. The easier crossing conditions allowed younger adults to perform the task without dual-task costs (93% success rate overall), but older adults were less successful at crossing the street when conversing on a cell phone (81%) compared to when listening to music (87%) or undistracted (88%). Interestingly, whenever crossing performance was impaired, participants also spent a longer amount of time on the sidewalk preparing to initiate their crossing (∼2 s in both Experiments). We speculate that the dual-task costs associated with crossing a street under distraction are attributable, in part, to less efficient encoding of visual information and a diminished ability to recognize and act on safe crossing gaps. Additionally, older adults appear to be less flexible in dividing attention across competing tasks.