 Dual task walking performance: A custom computer application which works with the Gyration motion mouse was developed for this purpose. The cognitive game task was similar to the Useful Field of View test the UFOV. The goal of the test game is to move a paddle game sprite to catch falling bright circle objects targets moving vertically top to bottom, and to avoid other shape or colors game objects dis-tractors. The objects appear at user defined fixed intervals e.g. 2 seconds and at random locations on the monitor. The game is instrumented with an assessment module. This generates a logged game file recording 80 Hz the following signals associated with player performance with respect to game events: i time index and coordinates of each game object and ii position coordinates of the game paddle slaved to head rotation. Features of the test game events provide a basis for objective quantification of cognitive functions, which include. i game success rate percentage of target caught, ii average motor response time time from appearance of the target to start of the paddle movement, iii average movement execution time iv movement efficiency. The cognitive game task is first performed in standing single tasks and then during treadmill waking at 0.9 ms dual-task walking condition. The difference in spatial -temporal gait variables during walk alone as describe above and dual task walking condition will be used to index dual-task performance. 