Be alert. You will see a circle displayed on the screen.

You will have to click on the circle the very moment it appears.

Once you click the first circle, another circle with random size, color and position will appear on the screen.

Click on this next circle too the very moment you see it.

Repeat steps 3 and 4 as long as circles continue to appear. ( around 21 circles ).

Finally you will see a table having data of your selection time, target distances to circle and circle dimensions.

Observe the graph carefully and analyse the results.