Reading text messages at different stages of pedestrian circumvention affects strategies for collision avoidance in young and older adults.

Abstract

BACKGROUND\nReading text messages is associated with accidents while walking in community places.\n\n\nRESEARCH QUESTION\nTo what extent does reading text messages at different stages of obstacle circumvention affect avoidance strategies while walking in young vs. older adults?\n\n\nMETHODS\nSixteen healthy young and 14 older adults were assessed while walking and viewing a virtual environment (VE) simulating a subway station with three virtual pedestrians positioned 7.5\u202fm away from the participant in the centre (0°), left and right (±40°). As participants advanced 0.5\u202fm towards a target in the far space, a virtual pedestrian randomly approached them. Text messages were delivered at onset of pedestrian movement (0.5\u202fm; early message) or during obstacle circumvention (2.5\u202fm; late message). A Vicon motion capture system captured trajectory displacement while walking.\n\n\nRESULTS\nIn both age groups, accuracy of message report (AMR) was reduced for early compared to late messages (p\u202f<\u202f0.001), although older adults showed larger deterioration (p\u202f<\u202f0.001) compared to younger participants. Locomotor outcomes (obstacle clearance, onset time of avoidance and walking speed) showed no differences between young and older participants (p\u202f>\u202f0.05). Early messages led to slower walking speed (p\u202f<\u202f0.001) and more frequent collisions compared to late messages and the no-message condition. Late messages yielded faster walking speed (p\u202f<\u202f0.001) and onset time of avoidance (p\u202f<\u202f0.02) compared to the other conditions.\n\n\nSIGNIFICANCE\nResults indicate that the stage of an avoidance strategy at which text messages are received impacts on pedestrian circumvention, with early messages posing a greater challenge to collision avoidance. In older adults, the reduced AMR suggests larger dual-task interference and prioritization of the walking task. The lack of further walking speed reduction in older vs. young adults may put them at greater risk of collisions in crowded, unpredictable community environments.