The Rotation Flicker app provides a test for measuring your perceptual processing speed.
 Website for download:
Full description:
The Flicker Fusion Threshold (FFT) is a commonly used measure of perceptual acuity that records the speed at which a flashing light can still be perceived as flickering and does not appear to have fused into a single image. The FFT has been found to be sensitive to a number of factors, including drugs, age, and fatigue (Simonson & Brozek, 1952; Davis, 1955). Perhaps due to the relationship between intelligence and information processing speed (Fry, 2000), the FFT has also been found to correlate with intelligence aptitude (Cautela & Barlow, 1965).
The Rotation Flicker app provides a modified version of the FFT test that measures the speed at which two alternating objects (images of propellers that alternate in position) are perceived to be rotating in motion (due to the phi phenomenon and stroboscopic effect) and do not appear to be just flickering in place.