Checker Shadow Illusion

Checker_shadow_illusion

The Checker Shadow Illusion is created by a checkerboard pattern composed of squares with different luminance values, the squares that are not directly illuminated by the light source appear darker than the illuminated squares, creating the illusion of shadows. The illusion is more pronounced when the squares are of high contrast, the light source is positioned at an oblique angle, and the checkerboard pattern is viewed from a distance.

The Checker Shadow illusion is an example of how our visual system can be misled by certain patterns and how the relative luminance can affect our perception of shadows and depth. It shows how the visual system uses the information from the image to infer the presence of shadows and depth even when it isn’t there.

Edelson-Checker_shadow_illusion
Checker Shadow Illusion


Table of Contents

How does the Checker Shadow Illusion work?

The Checker Shadow Illusion works by manipulating the relative luminance of the squares in a checkerboard pattern and the position of a light source.

Our visual system uses the information from the image to infer the presence of shadows and depth, and when the squares in the checkerboard pattern are of high contrast, the light source is positioned at an oblique angle, and the pattern is viewed from a distance, it creates the illusion of shadows on the squares that are not illuminated by the light source.

The illusion works because our visual system interprets the relative luminance of the squares in the checkerboard pattern as a cue for the presence of shadows and depth.

When the squares are of high contrast, our visual system assumes that the illuminated squares are closer to the light source and the dark squares are farther away, creating the illusion of shadows on the dark squares.

Additionally, the illusion is also influenced by the way our visual system processes the information in the image, such as the size, shape, and color of the squares, and the position of the light source.

The illusion is more pronounced when the light source is positioned at an oblique angle, because it creates more contrast between the illuminated and dark squares, and when the checkerboard pattern is viewed from a distance, because it makes the illusion more realistic.

In summary, the Checker Shadow Illusion works by manipulating the relative luminance of the squares in a checkerboard pattern and the position of a light source, which creates the illusion of shadows on the squares that are not illuminated by the light source, tricking the visual system into interpreting the pattern as having depth and shadows.

Versions of the Checker Shadow Illusion

The following is an alternate version of the Checker Shadow Illusion:



Edelson-Checker_shadow_illusion-solution
Adding the Vertical Bars makes it easier to see the true color of the squares





Illusions like the Checker Shadow Illusion

The Checker Shadow Illusion is a type of visual illusion known as a “perception illusion” or “perceptual illusion”. These types of illusions are created by manipulating the visual information in an image in a way that tricks the visual system into interpreting it differently from how it actually is.

In the case of the Checker Shadow Illusion, the visual information is manipulated by using a high-contrast checkerboard pattern and a light source positioned at an oblique angle, creating the illusion of shadows on the squares that are not illuminated by the light source, even though there are no actual shadows present in the image.

Perception illusions like the Checker Shadow Illusion, demonstrate how our visual system uses cues such as relative luminance, depth and shadows, to interpret the visual information and how easily it can be misled. These types of illusions are used to study how the visual system processes visual information and to better understand the underlying mechanisms of perception.

Some related illusions include the following:

The simultaneous contrast illusion is a visual effect that occurs when the perception of a color is affected by the colors of the surrounding area.

The illusion creates the appearance of a change in the color of an object, even though the actual color of the object remains constant.

Simultaneous Contrast Effect
The center green dot is the same on both sides, but the surrounding color changes the perception

The Neon Color Spreading illusion refers to the visual phenomenon where an area of color appears to spread or “bleed” beyond its intended boundaries.

Neon Color Spreading
From Wikimedia Commons

The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.  

Bezold_Effect
from Wikimedia Commons

The Mach Band Illusion: This illusion is created by the way the brain perceives edges of an object. When an object has a gradient of color, the edges of the object appear to be darker or lighter than they actually are.

Mach Bands Animation
From Wikimedia Commons

The Chevreul Illusion: This illusion is created by the way the brain perceives edges of an object. When the edges of an object are surrounded by a contrasting color, the edges appear to be a different color than they actually are. Chevreul’s illusion is similar to Mach bands, but they work in different ways. Chevreul’s illusion is an effect on the perception of hue, while Mach bands is an effect on the perception of brightness.

chevreul

The Hermann Grid Illusion: This illusion is created by the way the brain perceives intersections of lines. When the intersections of a grid of lines are viewed, small gray dots appear at the intersections, even though they are not actually there.



Hermann Grid

The Watercolor Illusion: This illusion is created by the way the brain perceives edges of an object. When an object is surrounded by a colored halo, the object appears to have a different color than it actually does.

Watercolor Illusion


The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion


Discovery of the Checker Shadow Illusion

The Checker Shadow Illusion was created by published by Edward H. Adelson in 1995.

Edward H. Adelson is a professor of Vision Science at the Massachusetts Institute of Technology (MIT). He is known for his research in the field of visual perception, particularly his work on the perception of lightness, color, and texture.

Adelson is best known for his work on the Checker-shadow Illusion. It was first published in 1995. He also made several other contributions to the field of visual perception, such as his research on the perception of color and texture, the perception of lightness and the perception of depth and motion. He has published many papers and articles on these topics and is widely considered to be one of the leading experts in the field of visual perception.

Adelson received his B.A. from Harvard University and his Ph.D. from MIT. He has received numerous awards for his work, including the David Marr Prize from the Cognitive Science Society and the Troland Research Award from the National Academy of Sciences. He is a Fellow of the American Association for the Advancement of Science, the American Psychological Association, and the Optical Society of America.

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Chubb Illusion

Chubb Illusion

The Chubb illusion is based on the perception of brightness and can be observed when a small bright patch is surrounded by a larger dark area, the small bright patch will appear brighter than the same patch surrounded by a bright area.

This illusion is thought to be related to how the human visual system processes contrast and brightness in an image.

The center area of the two images below are exactly the same, but appear different because the background is different.

Chubb Illusion
Chubb Illusion


Table of Contents

How does the Chubb Illusion work?

The Chubb illusion works by creating a contrast effect between a small bright patch and the surrounding area. The perception of brightness is not solely determined by the absolute luminance of an object, but also by the relative luminance of the surrounding area. When a small bright patch is surrounded by a larger dark area, the small bright patch will appear brighter than it actually is, because our eyes perceive the contrast between the bright patch and the dark background to be greater.

The Chubb illusion works by manipulating the relative luminance of the surrounding area in a way that influences how our visual system perceives the brightness of the central patch. This effect is thought to be related to the way our visual system processes contrast and brightness in an image, and it is influenced by factors such as the size, shape and color of the surrounding area.

It’s also worth mentioning that the Chubb Illusion is a part of the family of the Contrast illusions, which are based on the perception of relative luminance. The Hermann Grid illusion and the scintillating grid illusion are examples of other contrast illusions.

Versions of the Chubb Illusion

The following is an alternate version of the Chubb Illusion:



Chubb Illusion





Illusions like the Chubb Illusion

Color illusions work by exploiting the way that the human visual system processes color and light. The human eye is able to detect light in the visible spectrum, which consists of different wavelengths of light that correspond to different colors. The brain then interprets this information to create our perception of color. However, the way the brain perceives color is not always a perfect representation of the physical reality.

There are several factors that can influence the way that the visual system processes color and light, which can lead to the perception of illusions. These factors include:

Contrast: The way that the brain perceives color can be influenced by the surrounding colors and patterns. High-contrast borders around an area of color can cause the brain to interpret the color as spreading or “bleeding” beyond the actual boundaries of the object.

Lighting conditions: The way that the brain perceives color can also be affected by the lighting conditions. For example, when an object is viewed in bright light, the eye’s color receptors may become fatigued, causing the brain to perceive colors differently than they actually are.

Color adaptation: The brain adapts to the colors that we see over time, which can influence the perception of color. For example, if an individual looks at a red object for an extended period of time, the brain will adapt to the red, and when that person looks at a white object, it will appear to have a pinkish hue.

Color constancy: The brain is able to adjust the perception of color based on the context in which it is viewed. This can create illusions where the same color appears to be different depending on the surrounding colors.

Shape use: Some illusions like the Hermann grid illusion or the Cafe Wall illusion, use specific patterns and shapes to manipulate the perception of color and shape.

Some related illusions include the following:

The simultaneous contrast illusion is a visual effect that occurs when the perception of a color is affected by the colors of the surrounding area.

The illusion creates the appearance of a change in the color of an object, even though the actual color of the object remains constant.

Simultaneous Contrast Effect
The center green dot is the same on both sides, but the surrounding color changes the perception

The Neon Color Spreading illusion refers to the visual phenomenon where an area of color appears to spread or “bleed” beyond its intended boundaries.

Neon Color Spreading
From Wikimedia Commons

The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.  

Bezold_Effect
from Wikimedia Commons

The Mach Band Illusion: This illusion is created by the way the brain perceives edges of an object. When an object has a gradient of color, the edges of the object appear to be darker or lighter than they actually are.

Mach Bands Animation
From Wikimedia Commons

The Chevreul Illusion: This illusion is created by the way the brain perceives edges of an object. When the edges of an object are surrounded by a contrasting color, the edges appear to be a different color than they actually are. Chevreul’s illusion is similar to Mach bands, but they work in different ways. Chevreul’s illusion is an effect on the perception of hue, while Mach bands is an effect on the perception of brightness.

chevreul

The Hermann Grid Illusion: This illusion is created by the way the brain perceives intersections of lines. When the intersections of a grid of lines are viewed, small gray dots appear at the intersections, even though they are not actually there.



Hermann Grid

The Watercolor Illusion: This illusion is created by the way the brain perceives edges of an object. When an object is surrounded by a colored halo, the object appears to have a different color than it actually does.

Watercolor Illusion


The Ishihara Illusion: This illusion is created by the way the brain perceives colors. When a color is surrounded by a contrasting color, the brain perceives the color to be different than it actually is.

Ishihara Plate 9
From Wikimedia Commons

The flash lag illusion is a visual illusion that is based on the perception of the temporal relationship between a moving object and a flash of light. The illusion occurs when a moving object is followed by a sudden flash of light, and the perceived location of the flash appears to be behind the actual location of the object.

Flash Lag
From Wikimedia Commons

The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion


Discovery of the Chubb Illusion

The Chubb illusion” was discovered by the psychologist John Chubb in 1990.

John Chubb was a British psychologist who was best known for his research in the field of visual perception. He was a lecturer at University College London and later a professor at the University of Sussex. He conducted many experiments on visual perception and published several papers and articles on the topic.

One of his most notable contributions is the discovery of the Chubb illusion, a visual illusion that demonstrates how the perception of brightness is influenced by the relative luminance of the surrounding area. He also worked on other areas of research such as motion perception, attention and visual search.

Chubb passed away in 2010, His work continues to be cited and referenced by other researchers in the field of visual perception and cognitive psychology.

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Todorovic Illusion

Todorović circle

The Todorovic illusion is a visual illusion where a central object or space appears to be surrounded by a halo of light, even though no such halo is present in the image.

The illusion is created by the presence of bright and dark areas around the object, which can create the perception of a halo or aura.

Todorović circle
Todorovic Illusion Example


Table of Contents

How does the Todorovic Illusion work?

The Todorovic illusion works by creating the perception of a halo or aura around a central object, even though no such halo is present in the image.

This illusion is created by the presence of bright and dark areas around the object, which can create the perception of a halo or aura.

The illusion is thought to be caused by the way our visual system processes and interprets the brightness and darkness of the surrounding areas.

The brain uses the brightness and darkness of the surrounding areas to infer the 3D shape and surface properties of the central object, and this can create the perception of a halo or aura.

Additionally, it is also thought that the Todorovic illusion is related to the visual system’s ability to automatically adjust the brightness of an image according to the surrounding brightness, this process is called “luminance adaptation” and it affects the perceived brightness of the central object.

The adaptation process to the surrounding brightness can create the illusion of a halo or aura around the central object.

Versions of the Todorovic Illusion

The following are some alternate versions of the Todorovic Illusion:



Todorović circle





Illusions like the Todorovic Illusion

Color illusions work by exploiting the way that the human visual system processes color and light. The human eye is able to detect light in the visible spectrum, which consists of different wavelengths of light that correspond to different colors. The brain then interprets this information to create our perception of color. However, the way the brain perceives color is not always a perfect representation of the physical reality.

There are several factors that can influence the way that the visual system processes color and light, which can lead to the perception of illusions. These factors include:

Contrast: The way that the brain perceives color can be influenced by the surrounding colors and patterns. High-contrast borders around an area of color can cause the brain to interpret the color as spreading or “bleeding” beyond the actual boundaries of the object.

Lighting conditions: The way that the brain perceives color can also be affected by the lighting conditions. For example, when an object is viewed in bright light, the eye’s color receptors may become fatigued, causing the brain to perceive colors differently than they actually are.

Color adaptation: The brain adapts to the colors that we see over time, which can influence the perception of color. For example, if an individual looks at a red object for an extended period of time, the brain will adapt to the red, and when that person looks at a white object, it will appear to have a pinkish hue.

Color constancy: The brain is able to adjust the perception of color based on the context in which it is viewed. This can create illusions where the same color appears to be different depending on the surrounding colors.

Shape use: Some illusions like the Hermann grid illusion or the Cafe Wall illusion, use specific patterns and shapes to manipulate the perception of color and shape.

Some related illusions include the following:

The simultaneous contrast illusion is a visual effect that occurs when the perception of a color is affected by the colors of the surrounding area.

The illusion creates the appearance of a change in the color of an object, even though the actual color of the object remains constant.

Simultaneous Contrast Effect
The center green dot is the same on both sides, but the surrounding color changes the perception

The Neon Color Spreading illusion refers to the visual phenomenon where an area of color appears to spread or “bleed” beyond its intended boundaries.

Neon Color Spreading
From Wikimedia Commons

The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.  

Bezold_Effect
from Wikimedia Commons

The Mach Band Illusion: This illusion is created by the way the brain perceives edges of an object. When an object has a gradient of color, the edges of the object appear to be darker or lighter than they actually are.

Mach Bands Animation
From Wikimedia Commons

The Chevreul Illusion: This illusion is created by the way the brain perceives edges of an object. When the edges of an object are surrounded by a contrasting color, the edges appear to be a different color than they actually are. Chevreul’s illusion is similar to Mach bands, but they work in different ways. Chevreul’s illusion is an effect on the perception of hue, while Mach bands is an effect on the perception of brightness.

chevreul

The Hermann Grid Illusion: This illusion is created by the way the brain perceives intersections of lines. When the intersections of a grid of lines are viewed, small gray dots appear at the intersections, even though they are not actually there.



Hermann Grid

The Watercolor Illusion: This illusion is created by the way the brain perceives edges of an object. When an object is surrounded by a colored halo, the object appears to have a different color than it actually does.

Watercolor Illusion


The Ishihara Illusion: This illusion is created by the way the brain perceives colors. When a color is surrounded by a contrasting color, the brain perceives the color to be different than it actually is.

Ishihara Plate 9
From Wikimedia Commons

The flash lag illusion is a visual illusion that is based on the perception of the temporal relationship between a moving object and a flash of light. The illusion occurs when a moving object is followed by a sudden flash of light, and the perceived location of the flash appears to be behind the actual location of the object.

Flash Lag
From Wikimedia Commons

The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion


Discovery of the Todorovic Illusion

This version was created by Vladan Todorovic, a psychologist and researcher who is known for his work in the field of visual perception and cognitive psychology. He is particularly known for his research on visual illusions and the neural mechanisms that underlie them.

He is a professor of psychology at the University of Belgrade, Serbia. He has published several papers and articles on visual perception and the neural mechanisms of visual illusions, including the Todorovic illusion which is named after him.

References and Resources

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Todorovic-White’s Illusion

Todorovic

There is a Todorovic illusion that is a version of White’s illusion

In the image below, the gray region bordered mostly by white appears lighter than the identical region bordered mostly by black.

Todorovic
Todorovic-White’s Illusion


Table of Contents

How does the Todorovic-White’s Illusion work?

The Todorovic-White’s illusion works by exploiting the way our visual system processes contrast.

Our visual system tends to perceive the gray bars as being more similar in color to the stripes that are closest to them, rather than as a neutral gray.

As a result, the gray bar on the white stripes appears lighter than the gray bar on the black stripes, even though they are the same color.

This is because the white stripes make the gray bar on them appear lighter in comparison, while the black stripes make the gray bar on them appear darker in comparison.

It is important to note that the illusion is not due to the bars themselves, but to the high-contrast background. If the background were uniform, there would be no illusion.

Versions of the Todorovic-White’s Illusion

The following are some alternate versions of the Todorovic White’s Illusion:



White's Illusion
Removing the full horizontal lines reveals the true color of the gray bars




White's Illusion



White's Illusion



Simultaneous Contrast Effect


Illusions like the Todorovic-White’s Illusion

Color illusions work by exploiting the way that the human visual system processes color and light. The human eye is able to detect light in the visible spectrum, which consists of different wavelengths of light that correspond to different colors. The brain then interprets this information to create our perception of color. However, the way the brain perceives color is not always a perfect representation of the physical reality.

There are several factors that can influence the way that the visual system processes color and light, which can lead to the perception of illusions. These factors include:

Contrast: The way that the brain perceives color can be influenced by the surrounding colors and patterns. High-contrast borders around an area of color can cause the brain to interpret the color as spreading or “bleeding” beyond the actual boundaries of the object.

Lighting conditions: The way that the brain perceives color can also be affected by the lighting conditions. For example, when an object is viewed in bright light, the eye’s color receptors may become fatigued, causing the brain to perceive colors differently than they actually are.

Color adaptation: The brain adapts to the colors that we see over time, which can influence the perception of color. For example, if an individual looks at a red object for an extended period of time, the brain will adapt to the red, and when that person looks at a white object, it will appear to have a pinkish hue.

Color constancy: The brain is able to adjust the perception of color based on the context in which it is viewed. This can create illusions where the same color appears to be different depending on the surrounding colors.

Shape use: Some illusions like the Hermann grid illusion or the Cafe Wall illusion, use specific patterns and shapes to manipulate the perception of color and shape.

Some related illusions include the following:

The simultaneous contrast illusion is a visual effect that occurs when the perception of a color is affected by the colors of the surrounding area.

The illusion creates the appearance of a change in the color of an object, even though the actual color of the object remains constant.

Simultaneous Contrast Effect
The center green dot is the same on both sides, but the surrounding color changes the perception

The Neon Color Spreading illusion refers to the visual phenomenon where an area of color appears to spread or “bleed” beyond its intended boundaries.

Neon Color Spreading
From Wikimedia Commons

The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.  

Bezold_Effect
from Wikimedia Commons

The Mach Band Illusion: This illusion is created by the way the brain perceives edges of an object. When an object has a gradient of color, the edges of the object appear to be darker or lighter than they actually are.

Mach Bands Animation
From Wikimedia Commons

The Chevreul Illusion: This illusion is created by the way the brain perceives edges of an object. When the edges of an object are surrounded by a contrasting color, the edges appear to be a different color than they actually are. Chevreul’s illusion is similar to Mach bands, but they work in different ways. Chevreul’s illusion is an effect on the perception of hue, while Mach bands is an effect on the perception of brightness.

chevreul

The Hermann Grid Illusion: This illusion is created by the way the brain perceives intersections of lines. When the intersections of a grid of lines are viewed, small gray dots appear at the intersections, even though they are not actually there.



Hermann Grid

The Watercolor Illusion: This illusion is created by the way the brain perceives edges of an object. When an object is surrounded by a colored halo, the object appears to have a different color than it actually does.

Watercolor Illusion


The Ishihara Illusion: This illusion is created by the way the brain perceives colors. When a color is surrounded by a contrasting color, the brain perceives the color to be different than it actually is.

Ishihara Plate 9
From Wikimedia Commons

The flash lag illusion is a visual illusion that is based on the perception of the temporal relationship between a moving object and a flash of light. The illusion occurs when a moving object is followed by a sudden flash of light, and the perceived location of the flash appears to be behind the actual location of the object.

Flash Lag
From Wikimedia Commons

The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion


Discovery of the Todorovic-White’s Illusion

This version was created by Vladan Todorovic, a psychologist and researcher who is known for his work in the field of visual perception and cognitive psychology. He is particularly known for his research on visual illusions and the neural mechanisms that underlie them.

He is currently a professor of psychology at the University of Belgrade, Serbia. He has published several papers and articles on visual perception and the neural mechanisms of visual illusions, including the Todorovic illusion which is named after him.

White’s illusion was discovered by Edward H. Adelson, a professor of Vision Science at the Massachusetts Institute of Technology (MIT) in the early 1990s.

He named it after the British scientist, David Whitfield, who discovered a similar illusion in the early 20th century.

Adelson’s version of the illusion is widely used in research on visual perception and is known for its ability to reveal the workings of the human visual system. Adelson’s discovery was first published in the paper “Perception of the Brightness of Gray Patches” in 1993.

Edward H. Adelson is a professor of Vision Science at the Massachusetts Institute of Technology (MIT).

He is known for his research in the field of visual perception and is particularly known for his discovery of White’s illusion. H

e is also known for his work on the perception of lightness and color, including the discovery of the “checker shadow” illusion and the development of the “lightness constancy” theory.

He has published numerous papers in scientific journals, and has also been recognized for his contributions to the field with numerous awards and honors.

He is a Fellow of the American Association for the Advancement of Science, the American Psychological Association, and the Optical Society of America.

He received a BA from Harvard and a PhD from MIT, both in Physics.

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White’s Illusion

White's Illusion

White’s illusion is a visual phenomenon in which two identical gray bars are placed on a background of alternating black and white stripes.

The gray bars appear to be different shades of gray, with the one on the white stripes appearing lighter than the one on the black stripes.

This illusion is caused by the contrast between the gray bars and the surrounding stripes, which can affect our perception of the gray bars’ brightness.

In the image below, both gray bars have the exact same color.

White's Illusion
White’s Illusion


Table of Contents

How does the White’s Illusion work?

White’s illusion works by exploiting the way our visual system processes contrast.

The gray bars in the illusion are surrounded by a background of alternating black and white stripes, which creates a high-contrast situation.

Our visual system tends to perceive the gray bars as being more similar in color to the stripes that are closest to them, rather than as a neutral gray.

As a result, the gray bar on the white stripes appears lighter than the gray bar on the black stripes, even though they are the same color.

This is because the white stripes make the gray bar on them appear lighter in comparison, while the black stripes make the gray bar on them appear darker in comparison.

It is important to note that the illusion is not due to the bars themselves, but to the high-contrast background. If the background were uniform, there would be no illusion.

Versions of the White’s Illusion

The following are some alternate versions of the White’s Illusion:



White's Illusion
Removing the full horizontal lines reveals the true color of the gray bars




White's Illusion



White's Illusion



Simultaneous Contrast Effect


Illusions like the White’s Illusion

Color illusions work by exploiting the way that the human visual system processes color and light. The human eye is able to detect light in the visible spectrum, which consists of different wavelengths of light that correspond to different colors. The brain then interprets this information to create our perception of color. However, the way the brain perceives color is not always a perfect representation of the physical reality.

There are several factors that can influence the way that the visual system processes color and light, which can lead to the perception of illusions. These factors include:

Contrast: The way that the brain perceives color can be influenced by the surrounding colors and patterns. High-contrast borders around an area of color can cause the brain to interpret the color as spreading or “bleeding” beyond the actual boundaries of the object.

Lighting conditions: The way that the brain perceives color can also be affected by the lighting conditions. For example, when an object is viewed in bright light, the eye’s color receptors may become fatigued, causing the brain to perceive colors differently than they actually are.

Color adaptation: The brain adapts to the colors that we see over time, which can influence the perception of color. For example, if an individual looks at a red object for an extended period of time, the brain will adapt to the red, and when that person looks at a white object, it will appear to have a pinkish hue.

Color constancy: The brain is able to adjust the perception of color based on the context in which it is viewed. This can create illusions where the same color appears to be different depending on the surrounding colors.

Shape use: Some illusions like the Hermann grid illusion or the Cafe Wall illusion, use specific patterns and shapes to manipulate the perception of color and shape.

Some related illusions include the following:

The simultaneous contrast illusion is a visual effect that occurs when the perception of a color is affected by the colors of the surrounding area.

The illusion creates the appearance of a change in the color of an object, even though the actual color of the object remains constant.

Simultaneous Contrast Effect
The center green dot is the same on both sides, but the surrounding color changes the perception

The Neon Color Spreading illusion refers to the visual phenomenon where an area of color appears to spread or “bleed” beyond its intended boundaries.

Neon Color Spreading
From Wikimedia Commons

The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.  

Bezold_Effect
from Wikimedia Commons

The Mach Band Illusion: This illusion is created by the way the brain perceives edges of an object. When an object has a gradient of color, the edges of the object appear to be darker or lighter than they actually are.

Mach Bands Animation
From Wikimedia Commons

The Chevreul Illusion: This illusion is created by the way the brain perceives edges of an object. When the edges of an object are surrounded by a contrasting color, the edges appear to be a different color than they actually are. Chevreul’s illusion is similar to Mach bands, but they work in different ways. Chevreul’s illusion is an effect on the perception of hue, while Mach bands is an effect on the perception of brightness.

chevreul

The Hermann Grid Illusion: This illusion is created by the way the brain perceives intersections of lines. When the intersections of a grid of lines are viewed, small gray dots appear at the intersections, even though they are not actually there.



Hermann Grid

The Watercolor Illusion: This illusion is created by the way the brain perceives edges of an object. When an object is surrounded by a colored halo, the object appears to have a different color than it actually does.

Watercolor Illusion


The Ishihara Illusion: This illusion is created by the way the brain perceives colors. When a color is surrounded by a contrasting color, the brain perceives the color to be different than it actually is.

Ishihara Plate 9
From Wikimedia Commons

The flash lag illusion is a visual illusion that is based on the perception of the temporal relationship between a moving object and a flash of light. The illusion occurs when a moving object is followed by a sudden flash of light, and the perceived location of the flash appears to be behind the actual location of the object.

Flash Lag
From Wikimedia Commons

The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion


Discovery of the White’s Illusion

White’s illusion was discovered by Edward H. Adelson, a professor of Vision Science at the Massachusetts Institute of Technology (MIT) in the early 1990s.

He named it after the British scientist, David Whitfield, who discovered a similar illusion in the early 20th century.

Adelson’s version of the illusion is widely used in research on visual perception and is known for its ability to reveal the workings of the human visual system. Adelson’s discovery was first published in the paper “Perception of the Brightness of Gray Patches” in 1993.

Edward H. Adelson is a professor of Vision Science at the Massachusetts Institute of Technology (MIT).

He is known for his research in the field of visual perception and is particularly known for his discovery of White’s illusion. H

e is also known for his work on the perception of lightness and color, including the discovery of the “checker shadow” illusion and the development of the “lightness constancy” theory.

He has published numerous papers in scientific journals, and has also been recognized for his contributions to the field with numerous awards and honors.

He is a Fellow of the American Association for the Advancement of Science, the American Psychological Association, and the Optical Society of America.

He received a BA from Harvard and a PhD from MIT, both in Physics.

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Filled Space Illusion

Oppel-Kundt Filled Space Illusion

In the filled space illusion (or Oppel–Kundt illusion) The line B is equidistant between A and C but appears closer to A.

This is because the filled space between B–C appears larger than the unfilled space between A–B.

Oppel-Kundt Filled Space Illusion
Filled Space Illusion

Table of Contents


How does the Filled Space Illusion work?

The Oppel–Kundt Illusion is also known as the filled space illusion. It a visual illusion where an enclosed area appears to be larger or smaller than it actually is, depending on the amount of detail or texture within the area. The illusion is created by the brain’s perception of the amount of “visual mass” within the enclosed area.

For example, in the filled space illusion, an enclosed area filled with a lot of detailed or textured elements will appear smaller than an enclosed area with less detail or texture. This is because the brain perceives the detailed area as having more “visual mass” and thus it appears smaller. Conversely, an enclosed area with less detail or texture will appear larger, as the brain perceives it as having less “visual mass”.

This illusion works by the brain using the texture and details to make judgments about the size of an object, rather than relying solely on the object itself. This is similar to how the brain uses the surrounding elements in the Helmholtz illusion to make judgments about the size of an object.

It is also related to the concept of “figure-ground” perception, in which the brain organizes visual elements into distinct foreground and background regions, and the perception of the size of an area can be affected by the surrounding elements and how they are perceived as figure or ground.

Versions of the Filled Space Illusion

The following are a alternate versions of the Filled Space Illusion:

Oppel-Kundt Filled Space Illusion


Oppel-Kundt Filled Space Illusion


Illusions like the Filled Space Illusion

The following are some illusions similar to the Filled Space Illusion.

The Helmholtz Illusion. The square of horizontal lines appears to be taller and narrower than the identical square of vertical lines.

Helmholtz Illusion

The Zöllner illusion is a visual illusion in which parallel lines appear to be angled due to the presence of intersecting lines.

The illusion is often used to study the brain’s perception of shape and spatial relationships. It is considered one of the most powerful and striking examples of a geometrical-optical illusion. The perception of the illusion can be explained by the brain’s tendency to group lines together based on their similarity in direction and spacing, which can lead to an overestimation of the angle between the parallel lines.

Zöllner illusion


The Müller-Lyer illusion: This illusion involves lines with arrowheads at the ends, which can make a line appear longer or shorter depending on the direction of the arrowheads.

müller-lyer illusion



The Poggendorff illusion is a visual illusion in which the brain perceives a diagonal line as being interrupted by an object, even though the line is actually continuous. The illusion is created by the misalignment of two parallel lines that are intersected by a third line at a certain angle.

Poggendorff illusion transparent gray bar



The Orbison illusion is an illusion of movement that is created when stationary, parallel lines are placed on a background of radiating lines. The parallel lines appear to be moving in the direction of the radiating lines, even though they are actually stationary. This illusion is thought to be caused by the interaction between the parallel lines and the radiating lines, which creates an illusion of movement in the brain.

Orbison Illusion



The Wundt illusion is an optical illusion produces an inversed effect compared to the Hering Illusion. The vertical lines are both straight, but they may look as if they are curved inwards.

Wundt Illusion

The Cafe Wall Illusion is a geometric optical illusion that is created by the alignment of parallel lines in a checkerboard pattern. The parallel lines appear to be tilted or slanted, even though they are actually straight.



Discovery of the Filled Space Illusion / Oppel–Kundt Illusion

The illusion was described by German psychologist Karl Oppel and later independently by German physicist August Kundt.

Karl Oppel was a German psychologist who lived in the 19th century. He is best known for his work on visual perception, specifically for his description of the Oppel–Kundt Illusion in 1875. He was a professor of psychology at the University of Breslau.

He made significant contributions to the field of perception and visual cognition and his work on the Oppel–Kundt Illusion was considered an important early example of how context and surrounding elements can influence our perception of the world. His work laid the foundation for much of the research on visual perception that followed.

Karl Oppel also made important contributions to the field of sensory perception, particularly in the areas of touch, hearing and vision, as well as to the area of experimental psychology, where he developed techniques for measuring and analyzing sensory perception.

His work was widely recognized and respected in his field, and he was a member of several professional organizations, including the German Society for Psychology, the German Society for Anthropology, Ethnology and Prehistory, and the German Society for Experimental Psychology.

August Kundt was a German physicist who lived in the 19th century. He is best known for his work on the nature of sound and light, and for independently discovering the Oppel-Kundt illusion in 1877. Kundt’s discovery of the illusion was made independently of Karl Oppel, who had described a similar illusion three years earlier.

Kundt was a professor of physics at the University of Strasbourg, where he conducted research on a wide range of topics in physics, including the nature of sound and light, the properties of gases, and the nature of electricity and magnetism. He made important contributions to the field of acoustics, particularly in the areas of sound wave propagation and the study of musical instruments.

He also made significant contributions in the field of optics, where he developed a method for measuring the refractive index of a material by measuring the speed of light in that material. He also worked on the phenomenon of dispersion and the study of color, which helped in the development of the theory of color vision.

Kundt’s work was widely recognized and respected in his field, and he was a member of several professional organizations, including the German Physical Society and the Royal Society of Sciences in Heidelberg.

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Oppel–Kundt Illusion

Oppel-Kundt Filled Space Illusion

In the Oppel–Kundt (or filled space illusion) The line B is equidistant between A and C but appears closer to A.

This is because the filled space between B–C appears larger than the unfilled space between A–B.

Oppel-Kundt Filled Space Illusion
Oppel-Kundt “Filled Space”

Table of Contents


How does the Oppel–Kundt Illusion work?

The Oppel–Kundt Illusion is also known as the filled space illusion. It a visual illusion where an enclosed area appears to be larger or smaller than it actually is, depending on the amount of detail or texture within the area. The illusion is created by the brain’s perception of the amount of “visual mass” within the enclosed area.

For example, in the filled space illusion, an enclosed area filled with a lot of detailed or textured elements will appear smaller than an enclosed area with less detail or texture. This is because the brain perceives the detailed area as having more “visual mass” and thus it appears smaller. Conversely, an enclosed area with less detail or texture will appear larger, as the brain perceives it as having less “visual mass”.

This illusion works by the brain using the texture and details to make judgments about the size of an object, rather than relying solely on the object itself. This is similar to how the brain uses the surrounding elements in the Helmholtz illusion to make judgments about the size of an object.

It is also related to the concept of “figure-ground” perception, in which the brain organizes visual elements into distinct foreground and background regions, and the perception of the size of an area can be affected by the surrounding elements and how they are perceived as figure or ground.

Versions of the Oppel–Kundt Illusion

The following are a alternate versions of the Oppel–Kundt Illusion:

Oppel-Kundt Filled Space Illusion


Oppel-Kundt Filled Space Illusion


Illusions like the Oppel–Kundt Illusion

The following are some illusions similar to the Oppel–Kundt Illusion.

The Helmholtz Illusion. The square of horizontal lines appears to be taller and narrower than the identical square of vertical lines.

Helmholtz Illusion

The Zöllner illusion is a visual illusion in which parallel lines appear to be angled due to the presence of intersecting lines.

The illusion is often used to study the brain’s perception of shape and spatial relationships. It is considered one of the most powerful and striking examples of a geometrical-optical illusion. The perception of the illusion can be explained by the brain’s tendency to group lines together based on their similarity in direction and spacing, which can lead to an overestimation of the angle between the parallel lines.

Zöllner illusion


The Müller-Lyer illusion: This illusion involves lines with arrowheads at the ends, which can make a line appear longer or shorter depending on the direction of the arrowheads.

müller-lyer illusion



The Poggendorff illusion is a visual illusion in which the brain perceives a diagonal line as being interrupted by an object, even though the line is actually continuous. The illusion is created by the misalignment of two parallel lines that are intersected by a third line at a certain angle.

Poggendorff illusion transparent gray bar



The Orbison illusion is an illusion of movement that is created when stationary, parallel lines are placed on a background of radiating lines. The parallel lines appear to be moving in the direction of the radiating lines, even though they are actually stationary. This illusion is thought to be caused by the interaction between the parallel lines and the radiating lines, which creates an illusion of movement in the brain.

Orbison Illusion



The Wundt illusion is an optical illusion produces an inversed effect compared to the Hering Illusion. The vertical lines are both straight, but they may look as if they are curved inwards.

Wundt Illusion

The Cafe Wall Illusion is a geometric optical illusion that is created by the alignment of parallel lines in a checkerboard pattern. The parallel lines appear to be tilted or slanted, even though they are actually straight.



Discovery of the Oppel–Kundt Illusion

The illusion was described by German psychologist Karl Oppel and later independently by German physicist August Kundt.

Karl Oppel was a German psychologist who lived in the 19th century. He is best known for his work on visual perception, specifically for his description of the Oppel–Kundt Illusion in 1875. He was a professor of psychology at the University of Breslau.

He made significant contributions to the field of perception and visual cognition and his work on the Oppel–Kundt Illusion was considered an important early example of how context and surrounding elements can influence our perception of the world. His work laid the foundation for much of the research on visual perception that followed.

Karl Oppel also made important contributions to the field of sensory perception, particularly in the areas of touch, hearing and vision, as well as to the area of experimental psychology, where he developed techniques for measuring and analyzing sensory perception.

His work was widely recognized and respected in his field, and he was a member of several professional organizations, including the German Society for Psychology, the German Society for Anthropology, Ethnology and Prehistory, and the German Society for Experimental Psychology.

August Kundt was a German physicist who lived in the 19th century. He is best known for his work on the nature of sound and light, and for independently discovering the Oppel-Kundt illusion in 1877. Kundt’s discovery of the illusion was made independently of Karl Oppel, who had described a similar illusion three years earlier.

Kundt was a professor of physics at the University of Strasbourg, where he conducted research on a wide range of topics in physics, including the nature of sound and light, the properties of gases, and the nature of electricity and magnetism. He made important contributions to the field of acoustics, particularly in the areas of sound wave propagation and the study of musical instruments.

He also made significant contributions in the field of optics, where he developed a method for measuring the refractive index of a material by measuring the speed of light in that material. He also worked on the phenomenon of dispersion and the study of color, which helped in the development of the theory of color vision.

Kundt’s work was widely recognized and respected in his field, and he was a member of several professional organizations, including the German Physical Society and the Royal Society of Sciences in Heidelberg.

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Helmholtz Illusion

Helmholtz Illusion

The Helmholtz Illusion. The square of horizontal lines appears to be taller and narrower than the identical square of vertical lines.

Helmholtz Illusion
Helmholtz Illusion

Table of Contents


How does the Helmholtz Illusion work?

The Helmholtz illusion works by the brain being influenced by the context and surrounding elements when perceiving the size of an object. The brain uses the surrounding elements to make judgments about the size of an object, rather than relying solely on the object itself.

For example, in the classic Helmholtz illusion, a central circle is surrounded by smaller circles. The brain perceives the central circle as being larger than it actually is, because it is surrounded by smaller circles. This is because, the brain uses the surrounding circles as a reference point to judge the size of the central circle, and the smaller circles make the central circle appear larger in comparison.

Similarly, in fashion, the use of certain lines or patterns in clothing can create the illusion of a certain body shape or proportions. Horizontal lines, for example, can make the torso appear wider, while vertical lines can make the figure appear taller or slimmer.

Overall the Helmholtz illusion works by the brain uses the surrounding elements to make judgments about the size of an object and not just the object itself.

How does the Helmholtz Illusion work in Fashion?

The Helmholtz illusion can be used in fashion to create the illusion of a certain body shape or proportions.

For example, in clothing design, horizontal lines can be used to create the illusion of a wider torso, while vertical lines can create the illusion of a taller or slimmer figure.

Similarly, patterns or textures can be used to create the illusion of depth or volume on a garment, making it appear more visually interesting.

Additionally, in fashion photography, the Helmholtz illusion can be used to create the illusion of a certain body shape or proportions of a model by the way the photograph is shot and edited.

Versions of the Helmholtz Illusion

The following is an alternate versions of the Helmholtz Illusion demonstrating how it could be used in fashion

Helmholtz Illusion work in fashion



Illusions like the Helmholtz Illusion

The following are some illusions similar to the Helmholtz Illusion.

The Zöllner illusion is a visual illusion in which parallel lines appear to be angled due to the presence of intersecting lines.

The illusion is often used to study the brain’s perception of shape and spatial relationships. It is considered one of the most powerful and striking examples of a geometrical-optical illusion. The perception of the illusion can be explained by the brain’s tendency to group lines together based on their similarity in direction and spacing, which can lead to an overestimation of the angle between the parallel lines.

Zöllner illusion


The Müller-Lyer illusion: This illusion involves lines with arrowheads at the ends, which can make a line appear longer or shorter depending on the direction of the arrowheads.

müller-lyer illusion



The Poggendorff illusion is a visual illusion in which the brain perceives a diagonal line as being interrupted by an object, even though the line is actually continuous. The illusion is created by the misalignment of two parallel lines that are intersected by a third line at a certain angle.

Poggendorff illusion transparent gray bar



The Orbison illusion is an illusion of movement that is created when stationary, parallel lines are placed on a background of radiating lines. The parallel lines appear to be moving in the direction of the radiating lines, even though they are actually stationary. This illusion is thought to be caused by the interaction between the parallel lines and the radiating lines, which creates an illusion of movement in the brain.

Orbison Illusion



The Wundt illusion is an optical illusion produces an inversed effect compared to the Hering Illusion. The vertical lines are both straight, but they may look as if they are curved inwards.

Wundt Illusion

The Cafe Wall Illusion is a geometric optical illusion that is created by the alignment of parallel lines in a checkerboard pattern. The parallel lines appear to be tilted or slanted, even though they are actually straight.


The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.

Simultaneous Contrast Illusion



Discovery of the Helmholtz Illusion

The Helmholtz illusion was first described by German physicist and physiologist Hermann von Helmholtz in the 19th century.

Helmholtz was a pioneering researcher in the field of perception and visual cognition, and his work on the Helmholtz illusion was part of his broader research on how the brain processes visual information. He wrote about the illusion in his book “Handbook of Physiological Optics” in 1867.

Hermann von Helmholtz was a German physicist and physiologist who lived in the 19th century. He is considered one of the most important figures in the history of science, due to his many contributions to a wide range of fields, including physics, physiology, and philosophy.

He made significant contributions to the field of physiology by studying the nerve functions and the human brain. He also made important contributions to the field of physics, particularly in the area of optics, where he developed a mathematical theory of color vision and wrote a famous book “Handbook of Physiological Optics” in 1867.

In addition to his work on the Helmholtz illusion, he was also known for his research on the conservation of energy, the nature of sound and hearing, and the relationship between electricity and magnetism. He also made significant contributions to the field of physiology, particularly in the areas of sensory perception and neurological disorders.

He was awarded many honors and awards throughout his career, and his work laid the foundation for many of the scientific discoveries and technological advancements of the 20th century.

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Shake Your Head Illusion

Shake-Your-Head-Panda.jpg

The shake your head illusion is a type of visual illusion that is created when an image is viewed while the head is rapidly oscillating

Shake your head to see the hidden image….

Shake-Your-Head-Panda.jpg
Panda

What Is the Shake Your Head Illusion?

The shake your head illusion is a type of visual illusion that is created when an image is viewed while the head is rapidly oscillating. The illusion is characterized by the appearance of movement in a static image, as if the image is shaking or vibrating. This illusion is also known as the “headshake illusion” or “oscillopsia”.

The illusion is created by the rapid movement of the head, which causes the eyes to experience a temporary loss of visual stabilization, or “vestibulo-ocular reflex”, this makes the image appear to shake or vibrate. This illusion is similar to the effect seen when viewing an image through a moving train or car window, or when an image is displayed on a screen that is out of sync with the refresh rate.

The shake your head illusion is often used in research to study visual perception, as well as in the diagnosis and treatment of certain neurological conditions such as vestibular disorders or migraines.

How Does The Shake Your Head Illusion Work?

The shake your head illusion is a type of kinetic illusion. A kinetic illusion is a type of visual illusion that is characterized by the appearance of movement in a static image. This movement can be perceived in different ways, such as the image appearing to shake, vibrate, rotate, or change in size or shape. Kinetic illusions are caused by the movement of the viewer or the image, and they can occur in different forms, such as in optical illusions, visual hallucinations, or afterimages.

The shake your head illusion specifically falls under the category of “vestibular illusion”, which is a type of kinetic illusion caused by the movement of the viewer, in this case by shaking the head. It relies on the way the brain processes visual information, specifically the vestibulo-ocular reflex, which is the reflex that allows the eyes to stay stable and follow an object in motion, to create the illusion of movement.

In summary, the shake your head illusion, also known as the “headshake illusion” or “oscillopsia”, is a type of kinetic illusion specifically a vestibular illusion that is caused by the movement of the viewer, in this case shaking the head, and relies on the way the brain processes visual information.

Versions of the Shake Your Head Illusion

The following are some other examples of the Shake Your Head Illusion:

Shake-Your-Head-Optical-Illusion "Optical Illusion"
“Optical Illusion”


Shake-Your-Head-Optical-Illusion "Cool Dog"
Cool Dog



Illusions like the Shake Your Head Illusion

The following are some illusions that are related to the Autokinetic effect.


The Rotating Snakes is a peripheral drift illusion that consists of a grid of shapes, with some of them appearing to be rotating or undulating. The illusion is created by the interaction of the shapes with the neural processing of the visual system.

Rotating Snakes Autokinetic effect


The Moiré pattern illusion: This illusion is created by superimposing two similar patterns on top of each other, such as a grid of lines or circles. The resulting pattern appears to be moving or changing.

Moiré_pattern
From Wikimedia Commons

The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.

Simultaneous Contrast Illusion



The Hermann Grid Illusion, in which the intersections of a white grid on a black background appear to be gray, even though they are actually the same color as the background.

Hermann-Grid Illusion


The Zöllner Illusion, in which parallel lines appear to be tilted or bent when intersected by diagonal lines.

Zöllner illusion


The Fraser Spiral Illusion, in which a pattern of short, curved lines appears to form a spiral.

Fraser-spiral-illusion.



The Hering Illusion, in which two straight lines appear to be curved due to the presence of surrounding lines.

Hering Illusion


The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion



These illusions are usually caused by the way our eyes process visual information and the way the brain interprets it. They can also be caused by the interaction of different visual elements, such as lines and angles, in the image. They are often used in research on visual perception and the neural basis of perception.

Discovery of the Shake Your Head Illusion


The “Shake Your Head Illusion” was discovered by a team of researchers led by Dr. Tomohiro Ishihara at the University of Tokyo in Japan. The study was published in the journal “Current Biology” in June 2021.


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Fun Circles Illusory Motion

Illusory Motion Circles

With Illusory motion, static image appears to be moving due to the interaction of color contrasts, shapes, and position.

Illusory Motion Circles


Table of Contents


How does Illusory Motion work?

Illusory motion, also known as motion illusion, is the perception of movement in a static image or pattern.

This can occur when the brain is presented with a series of static images that change over time, or when certain visual patterns are arranged in a specific way.

The brain interprets these as if they are moving, even though the image or pattern itself is not actually moving.

There are several theories that try to explain the underlying mechanisms of illusory motion.

One theory is that it is a result of neural adaptation, where the visual system becomes adapted to certain stimuli and continues to respond as if they were present even after they are removed.

Another theory is that it is a result of the brain’s tendency to perceive patterns and to fill in missing information, known as Gestalt principles.

Versions of Illusory Motion

The following are some other examples of Illusory Motion





Illusory-Motion



Illusory-Motion




Illusory-Motion





Illusory-Motion








Illusory Motion




Illusory Motion










Peripheral drift illusion
From Wikimedia Commons


peripheral-drift-illusion-giving-a-throbbing-effect
From Wikimedia Commons



Peripheral_drift_illusion_blue-and-orange-wormhole


Illusions like Illusory Motion

The following are some illusions related to Illusory Motion

In Peripheral Drift illusions, the image or pattern appears to move or drift, even though it is actually stationary. This movement is caused by the brain’s attempt to interpret the image or pattern, which is often complex or ambiguous. The movement can be in any direction, such as horizontally, vertically, or diagonally.

Peripheral drift illusion jelly bean
From Wikimedia Commons

The rotating snakes is a peripheral drift illusion that consists of a grid of shapes, with some of them appearing to be rotating or undulating. The illusion is created by the interaction of the shapes with the neural processing of the visual system.

Rotating Snakes Autokinetic effect
A Version of Rotating Snakes


The Moiré pattern illusion: This illusion is created by superimposing two similar patterns on top of each other, such as a grid of lines or circles. The resulting pattern appears to be moving or changing.


Moiré_pattern
From Wikimedia Commons


The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.

Simultaneous Contrast Illusion



The Hermann Grid Illusion, in which the intersections of a white grid on a black background appear to be gray, even though they are actually the same color as the background.

Hermann-Grid Illusion


The Zöllner Illusion, in which parallel lines appear to be tilted or bent when intersected by diagonal lines.

Zöllner illusion


The Fraser Spiral Illusion, in which a pattern of short, curved lines appears to form a spiral.

Fraser-spiral-illusion.




The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion



These illusions are usually caused by the way our eyes process visual information and the way the brain interprets it. They can also be caused by the interaction of different visual elements, such as lines and angles, in the image. They are often used in research on visual perception and the neural basis of perception.


Discovery of the Illusory Motion

It is not clear who first discovered illusory motion. Some credit Aristotle in approximately 350 BC.

But these type of illusions have been observed and studied by various researchers over time, and many studies have contributed to the understanding of the phenomenon.

For example, peripheral drift illusions have been observed since the early 20th century and have been studied by various researchers in the field of visual perception, including scientists, psychologists, and neuroscientists.

Some of the early studies on peripheral drift illusions were conducted by the German physiologist Ernst Mach in the late 19th century, and later by the German psychologist Max Wertheimer in the early 20th century.

In the 20th century, several scientists and researchers have made significant contributions to the understanding of peripheral drift illusions and the underlying neural mechanisms, such as the American psychologist J.J. Gibson, the American neuroscientist David Hubel, and the British neuroscientist Melvyn Goodale.


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