Fig. 2.
Patterns of dual-task interference on gait and cognition among participants. The scatter plot displays each individual’s dual-task effect (DTE) for the gait task (gait speed) and for the cognitive task (response time during the normal executive function [EFnormal] task). DTE, calculated as [(dual-task value − single-task value)/single-task value] × 100%, equals zero when an individual’s performance on a given task is the same in the single-task and dual-task conditions. Positive DTE values indicate performance was better in the dual-task condition; negative DTE values indicate performance was worse in the dual-task condition. Participants in the genetic high risk group (APOE ε4 carriers) are represented in red; participants in the genetic low risk group are represented in blue. Gait priority trade-offs (gait speed improves during dual-task, while cognitive performance declines) were more often seen among low risk participants, whereas cognitive priority trade-offs (cognitive performance improves, while gait speed declines) were more often seen among high risk participants.