The Effects of Different Domains of Executive Function Dual Task Walking on Brain Activation and Gait Performance in Healthy Adults

The aim of this study is to investigate the effects of different domains of executive function (EF) during dual task walking condition on brain activation and gait performance in healthy adults. There are two experiments will be conducted in this study. Experiment 1 is a pilot study to determine the same level of difficulty in 3 EF domains, including inhibition, working memory and cognitive flexibility. Experiment 2 is carried out to investigate the effects of 3 different domains of EF which difficulties are controlled on gait performance and brain activation in dual task condition. 10 subjects will perform Stroop test (2s/3s/4s to change question), backward digit spans (3/4/5 digits) and naming test in Experiment 1. In Experiment 1, the primary outcome is the correct response speed (CRS) while secondary outcome will be the brain activity. In Experiment 2, 30 subjects will perform the single cognitive task A (SCTA, Stroop test), single cognitive task B (SCTB, backward digit spans), single cognitive task C (SCTC, naming test), single walking task (SWT), dual task A (DTA, walking while performing cognitive task A), dual task B (DTB, walking while performing cognitive task B) and dual task C (DTC, walking while performing cognitive task C). The CRS, gait performance, brain activity and the dual task costs (DTC) will be recorded in the Experiment 2. Brain activities in prefrontal cortex (PFC), premotor cortex (PMC) and supplementary motor area (SMAs) will be measured by functional near-infrared spectroscopy (fNIRS) during this study. One-way ANOVA with Tukey post-hoc test will be performed to establish the effect of different type of executive task on CRS or the brain activity. The differences of gait parameters and brain activity in different condition in the Experiment 2 will be examined by one-way ANOVA with repeated measured. Furthermore, the Pearson correlation coefficient will be used to examine the correlation of brain activation and executive function performance or gait parameters.