I think this illusion relies heavily on the high-frequency transitions between adjacent segments in the circles. If you "filter out" the high-frequency info. (by, say, squinting) much of the movement disappears. Perhaps those with less than perfect vision will have a harder time seeing the illusory motion because of this?
I'm guessing also that some have had trouble displaying this in class for two reasons: 1) Projections can have a lower contrast than the original, and this illusion relies on the high-contrast differences between the elements. 2) Note that different parts appear to move depending on where you're looking. This is a function of the size of the elements of the image and the size of the neural receptive fields in different parts of your retina (smaller in the center/fovea for finer detail). If the elements are made too large (say, by projecting on a large screen), that would reduce the effect of the illusion. (I've had troubles of this sort with other illusions presented via Powerpoint in my Sensation & Perception class.) Cheers, Chris -- Christopher T. Lovelace, PhD Assistant Professor Department of Psychology, University of Missouri - Kansas City 4825 Troost, Room 111-F, Kansas City, MO 64110 Voice: (816) 235-1067, Fax: (816) 235-1062 E-mail: [EMAIL PROTECTED] http://iml.umkc.edu/psyc/faculty/lovelace/ > From: Jeffrey Nagelbush <[EMAIL PROTECTED]> > Reply-To: Teaching in the Psychological Sciences <[EMAIL PROTECTED]> > Date: Mon, 12 Jul 2004 17:06:07 +0000 > To: Teaching in the Psychological Sciences <[EMAIL PROTECTED]> > Subject: RE: WOW-- Optical Illusion > > When I showed my wife the illusion she saw no movement. Since I saw lots of > movement, I was surprised. So my wife sat down and looked again for a > longer time. She gradually started to see movement. At first, she only saw > movement if she looked at one side (right or left). She saw slow movement > only on the extreme other side. She continued to look at the illusion and > suddenly said, I see it now. She now can see movement throughout the > picture. > > Any perception people have any explanation for this? > > Jeff Nagelbush > [EMAIL PROTECTED] > Ferris State University > > _________________________________________________________________ > Get tips for maintaining your PC, notebook accessories and reviews in > Technology 101. http://special.msn.com/tech/technology101.armx > > > --- > You are currently subscribed to tips as: [EMAIL PROTECTED] > To unsubscribe send a blank email to [EMAIL PROTECTED] --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED]
