Speed Limit on Attentional Tracking.
What you will see: You will see 8 black circles moving on a gray background.
To do: First, you will find the fastest speed at which you can track a single target. The numbers 1-15 correspond to different speeds. Just click on a number to try tracking an item at that speed. You will see 8 black circles on the screen. At the beginning, one circle will blink, and that's the one you should track. Then the items move for several seconds, and finally they stop. The target will turn red so you can check your accuracy. If you get it right, try a faster speed. Keep going until you find the maximum speed at which you can keep track of the target.
Important note:  Make sure to keep your eyes on the central "+" sign, and "mentally track" the target in your peripheral vision. We are testing how fast you can track things with your attention (rather than with your eyes).
•    Track 1 Target: 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14
Once you determine the fastest speed at which you can track 1 target, try to keep track of 4 targets at that speed. This time, 4 items will blink at the beginning, and you want to try your best to keep track of ALL 4 of them.
•    Track 4 Targets: 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14
To notice: You were probably able to keep track of 1 item quite fast, even without moving your eyes. However, when you divided your attention and tried to keep track of 4 items at that same speed, you probably experienced the items "scattering" immediately. If you tried to hang on to all 4 items, you likely lost them all. You might think that this is because you could never keep track of four things at once, but if you try a slower speed, there is likely to be a slower speed at which you can keep track of all four items perfectly.