Press the space bar and keep pressing it over and over again. Every time the button is pressed, a green check mark is shown and a sound is played simultaneously. Read the credits once you have completed the test.
Inspired by pg. 47 of David Eagleman's Incognito This test uses sound accompanied by sight to trick your brain into thinking that the checkmark always appears right when you press the spacebar and the sound plays. While this is true for the first few times you press the button, later a slight delay is inserted between the pressing of the spacebar and the checkmark appearing, the delay increasing incrementally, which you might have noticed at first before your brain tried to correct it. The sound always plays right when you press the spacebar, and your brain expects the checkmark to be shown with the sound, and that is what you see. Towards the end, if you really were immersed in the simulation, you might've seen the checkmark appear before you even pressed the button. This is because the delay got suddenly reverted back to 0 - and your brain was expecting to compensate for a delay.
