Operating a brain-actuated vehicle in real-world environments requires much of our visual attention. However, a typical brain-computer interface (BCI) sends the feedback information about the current status of the user's brain also via the visual channel. As a result, users have to split their visual attention into two: One for the surroundings and the other for the visual BCI feedback. Therefore, we recently developed a tactile stimulation system that successfully replaced the conventional visual feedback. Here we employ the multiple object tracking experiments to quantify the visual load added by the visual feedback. The result show that the additional visual load is almost eliminated, and the true negative rate of the BCI operation (intentional non-control) is improved when the visual feedback is replaced by the tactile feedback.