Participants were instructed to use the device to point in the
direction of the lit LED and then to move back to the origin of the
movement, which was indicated by the central LED. Participants
were told that the accuracy of the pointing orientation was
important and that they should maintain fixation on the display
throughout the test. In addition, they were told that the cursor
would not be visible during the task. Before starting the measurement,
participants were given time to practice until they felt
comfortable operating the device