Effects of Age on Obstacle Avoidance while Walking and Deciphering Text versus Audio Phone Messages

Abstract

Background: Widely popular among young, and more recently older adults, mobile phones are increasingly used while walking. Knowledge of the impact of phone message modality (e.g., text vs. audio) on the ability to avoid collisions with other pedestrians, however, remains limited. Objectives: This study aimed to investigate the extent to which the circumvention of an approaching pedestrian is affected by text versus audio phone messages in healthy young and older adults. Method: Sixteen young (aged 24 ± 3 years) and 14 older adults (aged 68 ± 4.5 years) were tested while walking and viewing a virtual environment depicted as a subway station in a helmet-mounted display. As they walked, one of three virtual humans randomly approached from the center (0°), right (+40°), or left (+40°). Phone messages, when present, were delivered at obstacle displacement onset and presented either as text messages on a virtual phone or as audio messages delivered through earphones. Participants were instructed to avoid collisions with pedestrians and to fully report the message content at the end of trials. Results: Both groups showed decreased accuracy of message report (AMR), slower walking speed, and more collisions in response to text versus audio messages. Compared to young adults, older adults showed greater reduction in AMR, more collisions, and similar speed adaptation in the presence of text messages. In both age groups, no significant differences in walking speed emerged between the audio message and the no-message condition, but only older adults experienced collisions and reduced AMR with the audio messages. Obstacle clearance and the onset time of avoidance strategy were not affected by message condition. Conclusions: Results suggest that coping with text messages while walking leads to greater risk of collision and alters message deciphering accuracy, while audio messages stand out as a safer and more efficient alternative for on-the-go communication. In general, older adults experienced larger motor-cognitive interference than younger adults, resulting in reduced AMR and more collisions without further changes in gait adaptation. Consequently, older adults failed to prioritize their safety when attending to phone messages while walking.