Rotating snakes 17

I produced several variants of "Rotating snakes" because this work seems to be preferred by many people.

since June 30, 2014

Original Research ARTICLE

Front. Psychol., 28 April 2015 | http://dx.doi.org/10.3389/fpsyg.2015.00542

Illusory visual motion stimulus elicits postural sway in migraine patients

Shu Imaizumi^1,2, Motoyasu Honma³, Haruo Hibino¹ and Shinichi Koyama^1,3,4*

¹Graduate School of Engineering, Chiba University, Chiba, Japan
²Japan Society for the Promotion of Science, Tokyo, Japan
³School of Medicine, Showa University, Tokyo, Japan
⁴School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore

Although the perception of visual motion modulates postural control, it is unknown whether illusory visual motion elicits postural sway. The present study examined the effect of illusory motion on postural sway in patients with migraine, who tend to be sensitive to it. We measured postural sway for both migraine patients and controls while they viewed static visual stimuli with and without illusory motion. The participants’ postural sway was measured when they closed their eyes either immediately after (Experiment 1), or 30 s after (Experiment 2), viewing the stimuli. The patients swayed more than the controls when they closed their eyes immediately after viewing the illusory motion (Experiment 1), and they swayed less than the controls when they closed their eyes 30 s after viewing it (Experiment 2). These results suggest that static visual stimuli with illusory motion can induce postural sway that may last for at least 30 s in patients with migraine.

http://journal.frontiersin.org/article/10.3389/fpsyg.2015.00542/full

Imaizumi S, Honma M, Hibino H and Koyama S (2015) Illusory visual motion stimulus elicits postural sway in migraine patients. Front. Psychol. 6:542. doi: 10.3389/fpsyg.2015.00542

<December 5, 2015>

"Rotating snakes"
(version 2015)

Disks appear to rotate.

Reply to a query

The illusion shown in the image consists of two illusions shown in the attached file. They belong to Type I of the optimized Fraser-Wilcox illusion, one being a motion illusion from dark to light and the other being one from light to dark.

There are two major hypotheses.

Hypothesis 1 (apparent movement hypothesis).

It is assumed that higher-contrast regions give a shorter latency to be visible than lower-contrast ones. This means that the former is seen first and the latter follows. Then, apparent movement is perceived in the direction from the former to latter.

Backus, B. T. and Oruç, I. (2005) Illusory motion from change over time in the response to contrast and luminance. Journal of Vision, 5, 1055-1069.

Conway, R. B., Kitaoka, A., Yazdanbakhsh, A., Pack, C. C., and Livingstone, M. S. (2005) Neural basis for a powerful static motion illusion. Journal of Neuroscience, 25, 5651-5656.

Hypothesis 2 (difference-of-motion-signal hypothesis).

It is assumed that given motion signals are stronger when the retinal image is moved from higher-contrast regions to lower-contrast ones than when it is slided from lower-contrast regions to high-contrast ones. This hypothesis needs involvement of constantly multidirected involuntary eye movement to feed the motion perception system with motion signals.

Murakami, I., Kitaoka, A. and Ashida, H. (2006) A positive correlation between fixation instability and the strength of illusory motion in a static display. Vision Research, 46, 2421-2431.

<June 5, 2015>