Role of impaired vision during dual-task walking in young and older adults

While cognitive-motor interference in dual-task activities is well established, it is still unknown how such interference is influenced by concurrent visual challenges. Nineteen community-dwelling healthy, cognitively intact, older adults (Mean ± SD = 71.45 ± 1.25 years, 6 males) and nineteen young adults (Mean ± SD = 22.25 ± 0.68 years, 4 males) performed a cognitive-single-task (serial subtraction by 3), a walking-single-task and a cognitive-walking-dual-task under normal, blurred and peripheral-vision-loss conditions (artificially imposed using goggles). Gait parameters and the number of correct responses were measured. Dual task costs for both walking and cognition were computed. Results showed that higher walking cost was seen with impaired vision (p = 0.05) and with older adults (p = 0.03); greater cognitive cost was seen with impaired vision (p = 0.01), but no difference in cognitive cost was seen between young and older adults. Thus, when faced with impaired vision, both young and older adults appear to allocate less attention to cognition than to walking, and thus prioritize walking. Future work should explore whether dual-task training under visual challenge could reduce cognitive-motor interference and reduce fall risks in older adults.