Motion Induced Blindness

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On the right you see a rotating array of blue crosses and 3 yellow dots. Now fixate the centre (watch the flashing green spot). Note that the yellow spots disappear once in a while: singly, in pairs or all three simultaneously. In reality, the 3 yellow spots are continuously present, honest! You can click on the ?/? buttons to change speed. Disappearence persists down to surprisingly low speeds.