Effects of gait and cognitive task difficulty on cognitive-motor interference in aging

Abstract

Although gait-related dual-task interference in aging is well established, the effect of gait and cognitive task difficulty on dual-task interference is poorly understood. The purpose of this study was to examine the effect of gait and cognitive task difficulty on cognitive-motor interference in aging. Fifteen older adults (72.1 years, SD 5.2) and 20 young adults (21.7 years, SD 1.6) performed three walking tasks of varying difficulty (self-selected speed, fast speed, and fast speed with obstacle crossing) under single- and dual-task conditions. The cognitive tasks were the auditory Stroop task and the clock task. There was a significant Group × Gait Task × Cognitive Task interaction for the dual-task effect on gait speed. After adjusting for education, there were no significant effects of gait or cognitive task difficulty on the dual-task effects on cognitive task performance. The results of this study provide evidence that gait task difficulty influences dual-task effects on gait speed, especially in older adults. Moreover, the effects of gait task difficulty on dual-task interference appear to be influenced by the difficulty of the cognitive task. Education is an important factor influencing cognitive-motor interference effects on cognition, but not gait.

Figure 1

Dual-task effects on gait speed (DTEg) shown as a function of cognitive task and group for (a) walking at self-selected speed, (b) walking at fastest comfortable speed, and (c) walking at fastest comfortable speed and stepping over on obstacle. The interaction between cognitive task and group was significant for the fast comfortable walking condition (b), but not for the other two gait tasks. Error bars indicate standard error of the mean. DTEg are adjusted values for education in the Gait Task × Cognitive Task × Group ANCOVA; n = 19 young adults, n = 12 older adults.