Figure 9. Effect of age on the performance of the two cognitive tasks during the dual-task situation.

The y-axis indicates the change in cognitive-task error rate relative to the baseline (single-task) condition. Means and standard deviations are shown for young adults (gray) and older adults (black); whiskers indicate standard deviations. Note the significantly increased error rates in the older adults (for both non-spatial and spatial-tasks), and the amplification of this age-related effect in the spatial-task trials. * indicates a significant main-effect (α=0.05) due to cognitive-task, § indicates a significant main-effect due to age, and † indicates a significant age×task interaction.