Motion Induced Blindness |
This is a great illustration of what we were taught about scanning outside the cockpit. We were told to scan the horizon for a short distance, stop momentarily, and repeat the process. I can remember being told why this was the most effective technique to locate other aircraft. It was emphasized repeatedly to not fix your gaze for more than a couple of seconds on any single object. The instructors, instructed us to continually "keep our eyes moving and our head on a swivel" because this was the best way to survive, not only in combat, but from peacetime hazards (like a midair collision) as well. We basically had to take the advice on faith (until we could experience for ourselves) because the technology to demonstrate it has only recently existed. |
Below you see a rotating array of blue crosses and 3 yellow dots. Now fixate on 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! |
What can you do |
You can use the slower/faster buttons to change speed. Disappearance persists down to surprisingly low speeds. [If there are no buttons on the right, please update your Flash player.] You can use the larger/smaller buttons to change size. Disappearance persists up to surprisingly large sizes. You can use the “back-col” button to change the background Color. The yellow dots disappear into whatever Color the background has. The ‘defaults’ button at the top restores the standard settings. Comments According to Michael Bach, "Steady fixation flavors disappearance, blinks or gaze shifts induce reappearance. All in all reminiscent of the Troxler effect, but stronger and more resistant to residual eye movements." Source This page provided by Prof. Michael Bach PhD, Ophthalmology, University of Freiburg, Germany, from his collection of Optical Illusions & Visual Phenomena. |