Comments on: Illusory motion with waves of almonds

By: doctorclark

doctorclark — Mon, 01 Oct 2007 15:22:53 +0000

A group called the Neural Correlate Society sponsors an annual competition for the best visual illusion (one that speaks in some way to the “neural underpinnings of visual illusory perception”).
Their extensive archives of winners and notable mentions going back to 2005 is where I first discovered the motion-without-animation illusion above, and their site showcases many other interesting illusions.
http://illusioncontest.neuralcorrelate.com
(check out the “Image archive” link)

By: Vaughan

Vaughan — Mon, 01 Oct 2007 12:55:16 +0000

I guess there’s two phenomena here. The first is the fact that light is indeed affected by the atmosphere, the second is whether the naked eye is sensitive enough to detect this phenomenon. The fact that the pinhole trick remarkably reduces the twinkling effect, suggests that they may be different.

By: celeriac

celeriac — Mon, 01 Oct 2007 11:53:05 +0000

This unattributed illusion was created by Akiyoshi Kitaoka at Ritsumeikan University in Japan. He has a very large site of illusions here:
http://www.ritsumei.ac.jp/~akitaoka/index-e.html
The mechanism of the illusion in question is explored in this paper (Conway et al. J. Neurosci 25(23):5651-5656):
http://www.jneurosci.org/cgi/content/full/25/23/5651
Since stars’ twinkling is readily observed by telescopes whose imaging devices are fixed solidly to the earth, I don’t buy eye movements as having much to do with twinkling. However in the case of the almonds illusion, any refreshing of the image on the retina (such as by eye movement) will elicit the illusion.