Posted by In the “motion standstill” illusion, a rapidly moving object is perceived as motionless, and yet not blurred. This means that color, depth, and shape are accurately processed while the motion system fails: in fact, subjects are no better at detecting the direction of motion than chance.
At slightly different frequencies than those which elicit standstill, subjects can even be below chance at guessing the direction of motion, indicating motion aliasing (also observed in the wagon wheel illusion).
One hypothesis about the mechanism driving this illusion is that the temporal frequency of motion that induces motion standstill actually matches the frequency with which the motion system samples the visual field. This is similar to an explanation offered of the wagon wheel illusion itself. An alternative interpretation of the wagon wheel illusion – that it reflects “Reichardt” motion detectors in the visual system – would seem inapplicable to motion standstill, potentially making it a good tool for understanding whether the human visual system does indeed have some kind of visual “refresh rate.”
(Incidentally, this work is being done by George Sperling, who early in his career discovered iconic memory.)
While (unsuccessfully) looking for an example of this fascinating illusion, I found this great collection of other motion illusions. Give the visual area MT in your temporal lobe a good workout!
My favorites:
Intersection Luminance and Plaid Motion
Can you identify the letters visible behind the gray background?
September 21, 2007
September 21, 2007
October 9, 2009
May 4, 2011
August 11, 2011
August 28, 2011