Invited Address "Motion illusions in stationary images"

Conference Center 4F 419, July 28, 2016, 11:30–12:10
31st International Congress of Psychology (ICP2016), Yokohama, Japan

Motion illusions in stationary images

Akiyoshi Kitaoka (Ritsumeikan University, Kyoto/Osaka, Japan)

since July 5, 2016 Handout

There are so many motion illusions in stationary images. First, I talk about the Fraser-Wilcox illusion group, which is characterized by 'automatical' illusory motion in the direction along special arrangements of visual stimuli.

Kitaoka, A. (2014). Color-dependent motion illusions in stationary images and their phenomenal dimorphism. Perception, 43(9), 914-925.

"Rotating snakes"

Each disk appears to rotate 'spontaneously' in the constant direction, from black to blue, white, yellow, back to black.

Color is not indispensable. Gray-scale images also work.

"Rotating snakes: a gray scale version"

Each disk appears to rotate 'spontaneously' in the constant direction, from black to dark gray, white, light gray, back to black.

A few years ago I discovered the color-dependent motion illusion.

Figure 6 of Kitaoka, A. (2014). Color-dependent motion illusions in stationary images and their phenomenal dimorphism. Perception, 43(9), 914-925.

Fraser and Wilcox showed a new phenomenon that stationary disks appear to rotate. They reported bimorphism or bistability of this illusion.

1. Fraser and Wilcox (1979)

Fraser, A. and Wilcox, K. J. (1979) Perception of illusory movement. Nature, 281, 565-566.

Ambiguity in the direction of illusory rotation

Alex Fraser was a professor of genetics and a painter!

Fogel, D. B. (2002). In Memoriam: Alex S. Fraser (1923–2002). IEEE Transactions on Evolutionary Computation, 6(5), 429-430.

Alex Fraser's original work

Adopted with permission from Alan Fraser (2006) "Alex Fraser, Geneticist and Painter" http://doctoralexfraser.blogspot.jp/

The perceptual bimorphism proposed by Fraser and Wilcox (1979) was not replicated for subsequent two decades.

2. Faubert and Herbert (1999)

Faubert, J. and Herbert, A. M. (1999) The peripheral drift illusion: A motion illusion in the visual periphery. Perception, 28, 617-621.

3. Naor-Raz and Sekuler (2000)

Naor-Raz, G. and Sekuler, R. (2000) Perceptual dimorphism in visual motion from stationary patterns. Perception, 29, 325-335.

We separated two illusions that cancel each other and proposed the optimized Fraser-Wilcox illusion.

4. Kitaoka and Ashida (2003)

Kitaoka, A. and Ashida, H. (2003) Phenomenal characteristics of the peripheral drift illusion. VISION (Journal of the Vision Society of Japan), 15, 261-262. PDF

Two illusion are cooperatively combined.

There are a few types of the optimized Fraser-Wilcox illusion.

Luminance gradient type (Type I)

The left disk appears to rotate counterclockwise while the right one clockwise.

"Dark to light"

"Light to dark"

"Dark to light" and "Light to dark"
are combined, giving a stronger illusion

Color enhances illusion.

The illusion from dark to light is enhanced by red or blue.

The illusion from light to dark is enhanced by yellow or green.

Both illusions work additively.

<Example> The upper-left, upper-right, and lower-middle disks appear to rotate counterclockwise while the rest clockwise.

Luminance step type (Type II)

<Example> The upper-left, upper-right, and lower-middle disks appear to rotate counterclockwise while the rest clockwise.

"Rollers"

Rollers appear to rotate without effort. On the other hand, they appear to rotate in the opposite direction when observers see this image keeping blinking.

"Dongururin"*

*Rotation of donguri (acorns). "Gururin" means rotation.

Rings of donguri appear to rotate.

"Rotating snakes"

Each disk appears to rotate 'spontaneously' in the constant direction, from black to blue, white, yellow, back to black.

Age and illusion

Another luminance step type (Type III)

<Example> The upper-left, upper-right, and lower-middle disks appear to rotate counterclockwise while the rest clockwise.

"Moving snakes with shadows"

Snakes appear to move horizontally.

Highlight and shadow type (Type IV)

<Example> The upper-left, upper-right, and lower-middle disks appear to rotate counterclockwise while the rest clockwise.

"Rotating tablets"

Rings appear to rotate.

Dark type

<Example> The upper-left, upper-right, and lower-middle disks appear to rotate counterclockwise while the rest clockwise.

Kitaoka, A. (2012). The Fraser-Wilcox illusion and its extension. Perception 41 ECVP Abstract Supplement, page 91 (Poster September 3, 2012). Poster PDF

Exception of the dark type
(kind of color-dependent type)

Kitaoka, A. (2012). The Fraser-Wilcox illusion and its extension. Perception 41 ECVP Abstract Supplement, page 91 (Poster September 3, 2012). Poster PDF

Color-dependent type

Kitaoka, A. (2014). Color-dependent motion illusions in stationary images and their phenomenal dimorphism. Perception, 43(9), 914-925.

Figure 6 of Kitaoka, A. (2014). Color-dependent motion illusions in stationary images and their phenomenal dimorphism. Perception, 43(9), 914-925.

Illusion remains when the image is not blurred.

Illusion occurs with red and blue.

Illusion occurs with red and green.

Twitching illusion, a variation of the color-dependent type

Kitaoka, A. (2014). A new type of the color-dependent Fraser-Wilcox illusion. Perception 43 (37th) ECVP (Belgrade) Abstract Supplement, page 20 (Poster #17 August 25, 2014). Presentation (html) --- Poster (doc) --- Handout (doc) --- Illusion Night Handout (jpeg) --- Illusion Night Questionnaire (docx)

(Ellipses: R255, G0, B0; Background: R140, G140, B140)
Illusory clockwise rotation is observed.

(Ellipses: R255, G0, B0; Background: R200, G0, B255)
Illusory clockwise rotation is observed.

(Ellipses: R255, G0, B0; Background: R200, G130, B130)
Illusory clockwise rotation is observed.

Red might play an important role in the twitching illusion.

a related phenomenon

Fading-dependent motion illusion

Kitaoka, A. (2014). Motion illusion induced by color changes. 10th Asia-Pacific Conference on Vision (APCV), Sunport Takamatsu, Takamatsu, Japan, (Poster July 20, 2014 (P2-16)). Poster MS-Word doc file --- Movie demos

(GIF)

(Flash)

rotredcyandisks3-m01.swf

Each disk appears to rotate clockwise during fading-in while counterclockwise during fading-out.

Fading-dependent motion illusion depends on replacing color.

(GIF)

(FLASH)

rotredcyandisks3-m04.swf

(Blue RGB = 0, 150, 255)

Color change-dependent motion illusion #2

(GIF)

(FLASH)

rotredcyandisks3-m05.swf

(Red RGB = 255, 0, 0)

(GIF)

(Flash)

"On-off rotating snakes: red and sky blue #1"

When fading in, each disk appears to rotate in the direction: black, red, white, sky blue, black. The direction is reversed when fading out.

(Flash)

"On-off rotating snakes: red and sky blue #2"

When fading in, each disk appears to rotate in the direction: black, sky blue, white, red, black. The direction is reversed when fading out.

Central drift illusion

Illusory motion is observed in the direction from parts of lower-contrast to parts of higher-contrast.

Kitaoka, A. and Ashida, H. (2004). A new anomalous motion illusion: the "central drift illusion". The 2004's winter meeting of the Vision Society of Japan at the Kogakuin University, Shinjuku, Tokyo, Japan, 2004/1/26-28, 1/26 oral publication. Presentation (html)

"Rotating pink boats"

Rings appear to rotate clockwise or counterclockwise moving toward each round head.

Expansion illusion of visual phantoms due to the central drift illusion

Drifting arrows illusion

Illusory motion is observed along arrows.

Type I: Arrows appear to move backward.

Type II: Arrows appear to move forward.

Drifting spines illusion family

The inset appears to move depending on smooth motion of retinal images.

"Drifting spines illusion"

The inset appears to move. The inset is a square but verticals appear to tilt clockwise and horizontals appear to tilt clockwise.

"Drifting Emboss illusion"
(sine type)

The inset appears to move.

"Illusion of Y-junctions"

The inset appears to move.

"Fraser illusion as a motion illusion"

The inset appears to move.

Phenomena

These images simultaneously show motion illusion and tilt illusion.

Explanation

I attribute this coexistence to 4-stroke motion and 4-stroke tilt illusion.

Kitaoka, A. (2010). The Fraser illusion family and the corresponding motion illusions. 33rd European Conference on Visual Perception (ECVP 2010), EPFL, Lausanne, Switzerland, 2010/8/22-26, 8/26 poster publication. Poster （Kitaoka, A. (2010) The Fraser illusion family and the corresponding motion illusions. Perception, 39, Supplement, #61, p. 178）

As tilt illusion, the Fraser illusion family consists of six (3 x 2) illusions.

There are eight fundamental combinations of basic components.

(The limiting case of the Fraser illusion family)

In each gray square, the middle line or edge appears to tilt counterclockwise.

These elements are shared with motion illusions in stationary images such as the drifting embosses illusion.

4-stroke motion corresponding to the Line Type

Finding: The direction of motion is the same as the tilt illusion.

<Mather's four-stroke motion>

Mather, G. and Murdoch, L. (1999) Second-order processing of four-stroke apparent motion. Vision Research, 39, 1795-1802.

cf. van Lier R, Csathó Á, 2005 “Dancing shapes: A comparison of luminance induced distortions” Perception, 35, 775 – 798.

4-stroke motion corresponding to the Edge Type

Finding: The direction of motion is the same as the tilt illusion.

<Mather's four-stroke motion>

cf. van Lier R, Csathó Á, 2005 “Dancing shapes: A comparison of luminance induced distortions” Perception, 35, 775 – 798.

4-stroke motion corresponding to the Mixed Type

Finding: The direction of motion is the same as the tilt illusion.

<Takeuchi's four-stroke motion>
Takeuchi, T. (1997) The motion analogue of the cafe wall illusion. Perception, 26, 569-584.

Then, anomalous motion illusions that coexist in tilt illusion images can be explained in this context.

When the retinal image slides in the special direction, the four-stroke motion is generated and motion illusion is observed.

Example

Drawn by Aliyoshi Kitaoka 2010 (June 25)

(Takeuchi's four-stroke motion)

Visual delay illusion

When retinal images are moved, parts of low-contrast and/or low-luminance (inset) appear to move due to visual delay against parts of high-contrastand/or low-luminance (surround).

Kitaoka, A. and Ashida, H. (2007). A variant of the anomalous motion illusion based upon contrast and visual latency. Perception, 36, 1019-1035.

Enhanced version of the fluttering heart illusion

When retinal images are moved, hearts appear to move.

Other illusions depending on retinal motion

Differences of spatial frequency generate motion illusion.

Drifting stripes illusion

Illusory motion is triggered by eye movement, blinks, or some events along the direction orthogonal to stripes.

"Hatpin urchin (pink)"

The image appears to wiggle in the radial direction.

"ICP2016 motion illusion"

Words or the background appear to move.

Continuation between the Ouchi illusion and the drifting stripes illusion

Op effect

So-called op effect can be include in motion illusion in stationary images.

Illusory radials appear to rotate.

Something appears to rotate quickly along blue circles (Enigma illusion).

Enigma illusion: Leviant, I. (1996) Does ‘brain-power’ make Enigma spin? Proceedings of the Royal Society of London, B, 263, 997-1001.

Scintillating grid illusion (Schrauf et al, 1997)

Schrauf, M., Lingelbach, B., Wist, E. R. (1997) The scintillating grid illusion. Vision Research, 37, 1033-1038.

Bergen grid illusion (Bergen, 1985)

Bergen, J. R. (1985). Hermann's grid: new and improved (abstract). Investigative Ophthalmology and Visual Science (Supplement), 26, 280.

Color grains appear to scintillate.

As global motion, there is

waving expression of motion illusion

in addition to parallel motion, rotation or radial motion.

Illusion of Y-junctions

Optimized Fraser-Wilcox illusion, Type IIa

"The bottom of the sea"

The image appears to wave.

Abstract
Motion illusions in stationary images are classified into three major categories depending on whether the illusory motion is rendered (1) by retinal motion of the image, (2) along particular repetitive patterns, or (3) by other factors. The first category consists of two subcategories, one showing illusory motion in the same direction as retinal motion (e.g., fluttering heart illusion) and the other displaying it in different directions (e.g., drifting spines illusion). The second category includes the extended family of the Fraser-Wilcox illusion that is characterized by strong illusion in the peripheral vision and no illusion in the central vision (e.g., Rotating snakes illusion). There are other types that show illusion in the central vision as well (e.g., drifting arrows illusion). The third category includes a variety of op effects (e.g., scintillating grid illusion). The roles of color, eye movements or adaptation levels in these illusions are discussed.

Thank you !

Akiyoshi's illusion pages

IA28-12 Sensation and Perception
Thursday, July 28, 11:30 – 12:10
Conference Center 4F 419
Motion illusions in stationary images
Kitaoka, Akiyoshi (Japan)
Introduction by Sakurai, Kenzo