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{{Short description|Optical illusion}}
[[File:Whites illusion.jpg|thumb|250 px|Figure 1. Rectangles A, on the left, look much darker than the rectangles B, on the right. However, rectangles A and B reflect the same amount of light.]]
[[File:Whites illusion.svg|thumb|Example of White's illusion]]
'''White's illusion''' is a brightness [[illusion]] where certain stripes of a black and white grating is partially replaced by a gray rectangle (Fig. 1). Both of the gray bars of A and B are the same color and [[opacity (optics)|opacity]]. The brightness of the gray pieces appear to shift toward the brightness of the top and bottom bordering stripes. This is in apparent opposition to [[lateral inhibition]] as it cannot explain this occurrence. This occurs even when the gray patches in the black stripes are bordered by more white than black (and conversely for the gray patches in the white stripes).<ref name="Anderson">Anderson, L Barton (2003). Perceptual organization and White's Illusion. ''Perception'', '''32''', 269-284. [http://www.psych.usyd.edu.au/staff/barta/lab/TexturedWhites.pdf]. Retrieved 15 February 2015.</ref> A similar illusion occurs when the horizontal strips have different colors; this is known as '''Munker-White's illusion''' or '''Munker's illusion'''.<ref>{{cite web|last1=Bach|first1=Michael|title=Munker Illusion|url=http://www.michaelbach.de/ot/col_Munker/index.html|accessdate=9 October 2014}}</ref><ref>{{cite web|last1=Bach|first1=Michael|title=http://www.michaelbach.de/ot/lum-white/index.html|url=http://www.michaelbach.de/ot/lum-white/index.html|accessdate=9 October 2014}}</ref>
'''White's illusion''' is a [[brightness]] [[illusion]] in which certain stripes of a black-and-white [[grating]] are replaced by gray rectangles (see the figure). Both of the gray bars of A and B have the same [[color]], [[luminance]], and [[opacity (optics)|opacity]]. The brightness of the gray rectangles appears to be closer to the brightness of the top and bottom bordering stripes. This is opposite to any explanation based on [[lateral inhibition]]; hence it cannot explain the illusion.<ref name="Anderson">{{cite journal |last1=Anderson |first1=L. Barton |year=2003 |title=Perceptual organization and White's Illusion |journal=Perception |volume=32 |issue=3 |pages=269–284 |doi=10.1068/p3216 |pmid=12729379 |s2cid=36001503 |url=http://www.psych.usyd.edu.au/staff/barta/lab/TexturedWhites.pdf |access-date=2016-07-18 |archive-date=2019-02-14 |archive-url=https://web.archive.org/web/20190214045800/http://www.psych.usyd.edu.au/staff/barta/lab/TexturedWhites.pdf |url-status=dead }}</ref> A similar illusion occurs when the horizontal stripes have different colors; this is known as the '''Munker–White illusion''' or the '''Munker illusion''', based on the [[Bezold effect]].<ref>{{cite web |last1=Bach |first1=Michael |title=Munker Illusion |url=http://www.michaelbach.de/ot/col_Munker/index.html |access-date=9 October 2014 |archive-date=18 October 2014 |archive-url=https://web.archive.org/web/20141018194928/http://www.michaelbach.de/ot/col_Munker/index.html |url-status=dead }}</ref><ref>{{cite web |last1=Bach |first1=Michael |title=Munker-White Illusion |url=http://www.michaelbach.de/ot/lum-white/index.html |access-date=9 October 2014}}</ref>


==Lateral inhibition==
==Lateral inhibition==
{{main|Lateral inhibition}}
{{main|Lateral inhibition}}
The amount of each [[bipolar cell]] response depends on the amount of the [[stimulation]] it receives from the [[Receptor (biochemistry)|receptor]] and the amount that this response is decreased by the lateral inhibition it receives from its neighboring cells.<ref>Sensation and perception, E. Bruce Goldstein, Edition 8, illustrated,Publisher Cengage Learning, 2009</ref>
The amount of each [[bipolar cell]] response depends on the amount of the [[stimulation]] it receives from the [[Receptor (biochemistry)|receptor]] and the amount that this response is decreased by the lateral inhibition it receives from its neighboring cells.<ref>Sensation and perception, E. Bruce Goldstein, Edition 8, illustrated, Publisher Cengage Learning, 2009</ref>


Lateral inhibition cannot explain White's illusion.<ref name=Anderson /> In Figure 2.1 lateral inhibition sent by black cells A and C should make cell O lighter; in Figure 2.2 lateral inhibition sent by white cells A and C should make cell O darker. It is suggested that brightness induction follows the brightness contrast in the direction of the bar not the surrounding area.
Lateral inhibition cannot explain White's illusion.<ref name=Anderson />{{Better source|reason=the Anderson article does not appear to argue this explicitly|date=June 2019}} In Figure 2.1 lateral inhibition sent by black cells A and C should make cell O lighter; in Figure 2.2 lateral inhibition sent by white cells A and C should make cell O darker. It is suggested that brightness induction follows the brightness contrast in the direction of the bar not the surrounding area.


===Lateral inhibition explained===
===Lateral inhibition explained===
[[File:Lateral Inhibition Diagram.png|thumb|250 px|Figure 2.]]
[[File:Lateral Inhibition Diagram.png|thumb|250 px|Figure 2]]
In Figure 2.1 we assume that light dropping on cells B and D generates a response of 100 units. Since the points A and C are darker we assume that only 20 units are generated from these points. Another assumption is that the lateral inhibition sent by each cell is 10% of its response; cells B and D send an inhibition of 10 units each and cells A and C send an inhibition of 2 units each. The inhibition sent by cells A and C is larger since their size is bigger than the size of cells B and D (let's say 2 times). This concludes that cell O receives an inhibition {{nowrap|I {{=}} 10 + 10 + 2 × 2 + 2 × 2 {{=}} 28.}}
In Figure 2.1 we assume that light dropping on cells B and D generates a response of 100 units. Since the points A and C are darker we assume that only 20 units are generated from these points. Another assumption is that the lateral inhibition sent by each cell is 10% of its response; cells B and D send an inhibition of 10 units each and cells A and C send an inhibition of 2 units each. The inhibition sent by cells A and C is larger since their size is bigger than the size of cells B and D (let's say 2 times). This concludes that cell O receives an inhibition {{nowrap|I {{=}} 10 + 10 + 2 × 2 + 2 × 2 {{=}} 28.}}


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===Experiments on lateral inhibition===
===Experiments on lateral inhibition===
White and White (1985) concluded that at a higher spatial frequency the grating of White's illusion could be described by brightness assimilation. They also concluded that at lower spatial frequencies White's illusion is still present.<ref>Bhaumik, Kamales, and Kuntal Ghosh. "Complexity in human perception of brightness: a historical review on the evolution of the philosophy of visual perception." OnLine Journal of Biological Sciences 10.1 (2010): 17+. Academic OneFile. Web. 2 Apr. 2012. Document URL http://go.galegroup.com.ezproxy.ltu.edu:8080/ps/i.do?id=GALE%7CA237135562&v=2.1&u=lom_lawrencetu&it=r&p=AONE&sw=w</ref>
[https://doi.org/10.1016/0042-6989(85)90049-5 White and White (1985)] concluded that at a higher spatial frequency the grating of White's illusion could be described by brightness assimilation. They also concluded that at lower spatial frequencies White's illusion is still present.{{cn|date=March 2020}}


Blakeslee and McCourt (2004) suggested that patterns whose scales are larger compared to the encoding filters (low spatial frequency are represented with a loss of low frequency information exhibiting brightness contrast); patterns whose scales are smaller compared to encoding filters (high spatial frequency), are represented with a loss of high frequency information exhibiting brightness assimilation.<ref>Bhaumik, Kamales, and Kuntal Ghosh. "Complexity in human perception of brightness: a historical review on the evolution of the philosophy of visual perception." OnLine Journal of Biological Sciences 10.1 (2010): 17+. Academic OneFile. Web. 2 Apr. 2012. Document URL http://go.galegroup.com.ezproxy.ltu.edu:8080/ps/i.do?id=GALE%7CA237135562&v=2.1&u=lom_lawrencetu&it=r&p=AONE&sw=w</ref><ref>{{cite journal|last1=Blakeslee|first1=Barbara|last2=McCourt|first2=Mark E.|title=A multiscale spatial filtering account of the White effect, simultaneous brightness contrast and grating induction|journal=Vision Research|volume=39 |year=1999|doi=10.1016/s0042-6989(99)00119-4 |pages=4361-4377|url=http://cseweb.ucsd.edu/~gary/cs200/w04/papers/blakeslee-99.pdf|accessdate=9 October 2014}}</ref>
Blakeslee and McCourt (2004) suggested that patterns whose scales are larger compared to the encoding filters (low spatial frequency) are represented with a loss of low frequency information exhibiting brightness contrast; patterns whose scales are smaller compared to encoding filters (high spatial frequency), are represented with a loss of high frequency information exhibiting brightness assimilation.<ref>{{cite journal|last1=Blakeslee|first1=Barbara|last2=McCourt|first2=Mark E.|title=A multiscale spatial filtering account of the White effect, simultaneous brightness contrast and grating induction|journal=Vision Research|volume=39 |year=1999|issue=26 |doi=10.1016/s0042-6989(99)00119-4 |pages=4361–4377|pmid=10789430 |url=http://cseweb.ucsd.edu/~gary/cs200/w04/papers/blakeslee-99.pdf|access-date=9 October 2014|doi-access=free}}</ref>


==Belongingness==
==Belongingness==
Our perception of an area's lightness is influenced by the part of the surroundings to which the area appears to belong.
Our perception of an area's lightness is influenced by the part of the surroundings to which the area appears to belong.


In the disc example (Fig. 3), the four discs on the left are identical to the four discs on the right in terms of how much light is reflected from the discs, that is to say, they are physically identical. The theory to explain the different psychological experiences is called belongingness.
A disc example consists of four discs on the left which are identical to four discs on the right in terms of how much light is reflected from the discs, that is to say, they are physically identical. The theory to explain the different psychological experiences is called belongingness.


The discs on the left appear dark and the ones on the right appear light, this is because of the two displays. In the display on the left, the dark area on the left seemingly belongs to the discs, and the discs are obscured by the light mist. On the right side, the same dark areas are interpreted as belonging to the dark mist. In the meanwhile, the white parts are seen as the color of the discs. Therefore, our perception of the lightness of the discs is significantly influenced by the display, which is the mist in this case (Anderson & Winawer, 2005).
The discs on the left appear dark and the ones on the right appear light, this is because of the two displays. In the display on the left, the dark area on the left seemingly belongs to the discs, and the discs are obscured by the light mist. On the right side, the same dark areas are interpreted as belonging to the dark mist. In the meanwhile, the white parts are seen as the color of the discs. Therefore, our perception of the lightness of the discs is significantly influenced by the display, which is the mist in this case (Anderson & Winawer, 2005).


The belongingness theory has been suggested as an explanation of White's illusion. According to belongingness theory, the lightness of rectangle A is influenced by the white display, which should be the white bars that surround it. Similarly, the rectangle B on the right side is surrounded by the dark bars, and the lightness of rectangle B is affected by the dark background. As a result, area A which rests on the white background appears darker than area B which rests on the dark background.<ref>{{cite journal|last1=Gilchrist et al.|first1=A|title=An Anchoring Theory of Lightness Perception|journal=Psychological Review|volume=106 (1999)|issue=4|pages=795-834|url=http://wexler.free.fr/library/files/gilchrist%20(1999)%20an%20anchoring%20theory%20of%20lightness%20perception.pdf|accessdate=9 October 2014}}</ref>
The belongingness theory has been suggested as an explanation of White's illusion. According to belongingness theory, the lightness of rectangle A is influenced by the white display, which should be the white bars that surround it. Similarly, the rectangle B on the right side is surrounded by the dark bars, and the lightness of rectangle B is affected by the dark background. As a result, area A which rests on the white background appears darker than area B which rests on the dark background.<ref>{{cite journal|last1=Gilchrist|first1=A|title=An Anchoring Theory of Lightness Perception|journal=Psychological Review|year=1999|volume=106 |issue=4|pages=795–834|url=http://wexler.free.fr/library/files/gilchrist%20(1999)%20an%20anchoring%20theory%20of%20lightness%20perception.pdf|access-date=9 October 2014|doi=10.1037/0033-295x.106.4.795|pmid=10560329|display-authors=etal}}</ref>


Belongingness theory only explains why rectangle A looks darker than rectangle B and does not discuss why the gray area on rectangle A looks darker than in rectangle B; secondly, when talking about the background, Belongingness theory appears quite the same as simultaneous contrast theory, they just use different names.<ref name="Anderson"/> Kelly and Grossberg (2000, P&P, 62, 1596-1619) explain and simulate these perceived differences and various other surface brightness and figure-ground percepts, such as those arising from Bregman-Kanizsa, Benary cross, and checkerboard displays, using the FACADE theory of 3-D vision and figure-ground perception.
Belongingness theory only explains why rectangle A looks darker than rectangle B and does not discuss why the gray area on rectangle A looks darker than in rectangle B; secondly, when talking about the background, Belongingness theory appears quite the same as simultaneous contrast theory, they just use different names.<ref name="Anderson"/> Kelly and Grossberg (2000, P&P, 62, 1596-1619) explain and simulate these perceived differences and various other surface brightness and figure-ground percepts, such as those arising from Bregman-Kanizsa, Benary cross, and checkerboard displays, using the FACADE theory of 3-D vision and figure-ground perception.


==See also==
==Other experiments/articles involving White's illusion==
* [[Bezold effect]]
*Anderson 2003<ref name="Anderson"/>
*Cornsweet and Teller 1965
*White 1979, 1981
*Shapley and Enroth-Cugell 1984
*Foley and McCourt 1985
*Grossberg and Todorovic 1988
*Moulden and Kingdom 1989
*Paradiso and Nakayama 1991
*Kingdom and Moulden 1991
*Taya et al 1995
*Anderson 1997
*Todorovic 1997
*Zaidi et al 1997
*Blakeslee and McCourt 1999
*Gilchrist et al 1999
*Kelly and Grossberg 2000
*Ripamonti and Gerbino 2001
{{cn}}


==References==
==References==
{{commons category}}
{{commons category}}
{{reflist}}
{{reflist}}

==External links==
* [https://www.popsci.com/red-skulls-look-purple-and-orange/ "These skulls look purple and orange. They are both red", by Nicole Wetsman], December 18, 2018, [[Popular Science]] magazine
* [https://michaelbach.de/ot/lum-white/White2010Color%20white%20illusion%20history.pdf The Early History of White's Illusion, Michael White, Colour: Design & Creativity (5) (2010): 7, 1–7, 2010]


{{Optical illusions}}
{{Optical illusions}}


[[Category:Optical illusions]]
[[Category:Optical illusions]]
[[Category:Color]]
[[Category:Visual perception]]

Latest revision as of 12:20, 10 June 2024

Example of White's illusion

White's illusion is a brightness illusion in which certain stripes of a black-and-white grating are replaced by gray rectangles (see the figure). Both of the gray bars of A and B have the same color, luminance, and opacity. The brightness of the gray rectangles appears to be closer to the brightness of the top and bottom bordering stripes. This is opposite to any explanation based on lateral inhibition; hence it cannot explain the illusion.[1] A similar illusion occurs when the horizontal stripes have different colors; this is known as the Munker–White illusion or the Munker illusion, based on the Bezold effect.[2][3]

Lateral inhibition

[edit]

The amount of each bipolar cell response depends on the amount of the stimulation it receives from the receptor and the amount that this response is decreased by the lateral inhibition it receives from its neighboring cells.[4]

Lateral inhibition cannot explain White's illusion.[1][better source needed] In Figure 2.1 lateral inhibition sent by black cells A and C should make cell O lighter; in Figure 2.2 lateral inhibition sent by white cells A and C should make cell O darker. It is suggested that brightness induction follows the brightness contrast in the direction of the bar not the surrounding area.

Lateral inhibition explained

[edit]
Figure 2

In Figure 2.1 we assume that light dropping on cells B and D generates a response of 100 units. Since the points A and C are darker we assume that only 20 units are generated from these points. Another assumption is that the lateral inhibition sent by each cell is 10% of its response; cells B and D send an inhibition of 10 units each and cells A and C send an inhibition of 2 units each. The inhibition sent by cells A and C is larger since their size is bigger than the size of cells B and D (let's say 2 times). This concludes that cell O receives an inhibition I = 10 + 10 + 2 × 2 + 2 × 2 = 28.

In Figure 2.2 with the same assumptions as above stated, cell O receives an inhibition of I = 10 × 2 + 10 × 2 + 2 + 2 = 44.

Because point O in Figure 2.1 receives an inhibition smaller than the point O in Figure 2.2 the gray cell should be lighter.

Experiments on lateral inhibition

[edit]

White and White (1985) concluded that at a higher spatial frequency the grating of White's illusion could be described by brightness assimilation. They also concluded that at lower spatial frequencies White's illusion is still present.[citation needed]

Blakeslee and McCourt (2004) suggested that patterns whose scales are larger compared to the encoding filters (low spatial frequency) are represented with a loss of low frequency information exhibiting brightness contrast; patterns whose scales are smaller compared to encoding filters (high spatial frequency), are represented with a loss of high frequency information exhibiting brightness assimilation.[5]

Belongingness

[edit]

Our perception of an area's lightness is influenced by the part of the surroundings to which the area appears to belong.

A disc example consists of four discs on the left which are identical to four discs on the right in terms of how much light is reflected from the discs, that is to say, they are physically identical. The theory to explain the different psychological experiences is called belongingness.

The discs on the left appear dark and the ones on the right appear light, this is because of the two displays. In the display on the left, the dark area on the left seemingly belongs to the discs, and the discs are obscured by the light mist. On the right side, the same dark areas are interpreted as belonging to the dark mist. In the meanwhile, the white parts are seen as the color of the discs. Therefore, our perception of the lightness of the discs is significantly influenced by the display, which is the mist in this case (Anderson & Winawer, 2005).

The belongingness theory has been suggested as an explanation of White's illusion. According to belongingness theory, the lightness of rectangle A is influenced by the white display, which should be the white bars that surround it. Similarly, the rectangle B on the right side is surrounded by the dark bars, and the lightness of rectangle B is affected by the dark background. As a result, area A which rests on the white background appears darker than area B which rests on the dark background.[6]

Belongingness theory only explains why rectangle A looks darker than rectangle B and does not discuss why the gray area on rectangle A looks darker than in rectangle B; secondly, when talking about the background, Belongingness theory appears quite the same as simultaneous contrast theory, they just use different names.[1] Kelly and Grossberg (2000, P&P, 62, 1596-1619) explain and simulate these perceived differences and various other surface brightness and figure-ground percepts, such as those arising from Bregman-Kanizsa, Benary cross, and checkerboard displays, using the FACADE theory of 3-D vision and figure-ground perception.

See also

[edit]

References

[edit]
  1. ^ a b c Anderson, L. Barton (2003). "Perceptual organization and White's Illusion" (PDF). Perception. 32 (3): 269–284. doi:10.1068/p3216. PMID 12729379. S2CID 36001503. Archived from the original (PDF) on 2019-02-14. Retrieved 2016-07-18.
  2. ^ Bach, Michael. "Munker Illusion". Archived from the original on 18 October 2014. Retrieved 9 October 2014.
  3. ^ Bach, Michael. "Munker-White Illusion". Retrieved 9 October 2014.
  4. ^ Sensation and perception, E. Bruce Goldstein, Edition 8, illustrated, Publisher Cengage Learning, 2009
  5. ^ Blakeslee, Barbara; McCourt, Mark E. (1999). "A multiscale spatial filtering account of the White effect, simultaneous brightness contrast and grating induction" (PDF). Vision Research. 39 (26): 4361–4377. doi:10.1016/s0042-6989(99)00119-4. PMID 10789430. Retrieved 9 October 2014.
  6. ^ Gilchrist, A; et al. (1999). "An Anchoring Theory of Lightness Perception" (PDF). Psychological Review. 106 (4): 795–834. doi:10.1037/0033-295x.106.4.795. PMID 10560329. Retrieved 9 October 2014.
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