Simple reaction time is the time it takes to react to stimuli. The average human's reaction time falls somewhere between 200 and 270 milliseconds, although athletes and others who train themselves can achieve reaction times approaching 150 milliseconds.

Complex reaction time is the latency between a variable stimulus and a respectively variable response. Some examples of common reaction time tasks are:

Go / NoGo (also called Recognition) reaction time tasks, in which participants respond to one particular event but are instructed to ignore other events or

Choice reaction time tasks, in which participants respond differentially to two stimuli by pressing one key for event A and a separate key for event B.

This test measures the time taken for you to press the stop button after the background color changes. You can select the color of the background will change to.