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The Kid Should See This

Zoom in, zoom out: The train speed illusion

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Psychology professor Akiyoshi Kitaoka is well-known for his exploration of perception and visual illusions, as seen in these videos: The footstep illusion and more optical tricks.

In the video above, Kitaoka notices that perceived speed may be different depending on how much visual information is included in one’s field of view. When he zooms in within the video, the train appears to travel slowly. Zoom out, and it’s speeding along again. Theoretical cognitive scientist Mark Changizi writes:

“The illusion that speed decreases when zoomed is because when one focuses on an inner portion of the movie, the optic flow angular speed is slow, and appears to fill one’s entire visual field, which is consistent with overall lower forward speed.

“Note: The more zoomed, the more densely packed the overhead rigging appears. So, even though you appear to be moving forward more slowly when zoomed in, the actual rate of rigging flowing by remains constant, consistent with same forward speed in all conditions.”

Watch the video and see what you perceive.

zoomed in: did the train slow down?
Perception is relative. Watch these videos next:
• Three visual tricks that can mislead your brain
• The Moon Illusion – TED Ed
• AsapScience asks: “Can you trust your eyes?”
• You can’t see this (Mind Tricks)
Cycloid illusion: Are these dots really moving in a circle?

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