Reminds me of a video I watched where they tested human perception of 60/90/120 FPS. They had an all white screen and flashed a single frame of black at various frame rates, and participants would press a button if they saw the change. Then repeated for an all black screen and a single frame of white would flash.

At 60 and 90 FPS, most participants saw the flash. At 120 FPS, they only saw the change going from black to white.