Zach- Visual Illusions

Visual Illusions result from a misinterpretation of visual stimulants which takes place as a result of either a pathological condition or a misperception of the stimulants. Simply put, what we see does not fit the properties of the object we are viewing.

The images below are 2-D but yet they all appear to be moving. As our brain perceives the images it sends signals that the object is moving even though we know it is a still picture.

Zach- Figure-Ground Perception

 Figure-Ground perception is when we perceive an image, we tend to simplify it by separating it into figure and ground. The figure is the object you perceive. The ground is everything in the background. This is what causes people to see variations in black and white images. Depending on which your brain depicts as the ground or figure will determine what you see in the image.

The image below will either be a vase looking object or two faces looking into each other, depending upon how your brain sorts the black or white.

Zach-Proximity

The tendency of objects to be associated more strongly with nearby objects than with those that are farther away. We automatically group similar items by position, by color, or by shape. This process of grouping can help us determine the meaning of the image.

The image below is just triangles assembled randomly, but our brain is able to use proximity to group these shapes together allowing us to see the Statue of Liberty.

Binocular cues Katie

Retinal disparity: When your retinas receive different images and when put together, you can percieve distance. For example, when looking cross-eye at your nose, you see that it is very close to your eyes. Then, when looking at your feet, you see that they are much more far away.

Convergence: The idea that the more the eyes converge inward, the closer the object to you. In this photo, for example, your eyes see the blue sphere as the closest because the rest of the picture causes your eyes too converge inward and focus on it.

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Brightness Constancy

Brightness Constancy is how we perceive an object as having a constant lightness even while its illumination may change. The light that we perceive also depends on relative luminance which is the amount of light an object reflects relative to its surroundings. For example when the sun shines on the flowers we still see it as the same color as when there is no light shining on them.

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Monocular Cues (cont.) Katie

-Interposition: When one object blocks out the view of another, we think that object is closer. For example, we see in this photo that the green triangle is the farthest away and the yellow circle is the closest. We perceive it this way because of how the shapes overlap.

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-Texture gradient:When the texture of an object changes, our perception of how far away it is changes. For example, in the photo below, the more widely spaced rows make us see that they are close. The more densely packed rows make us see that they are farther away.

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-Linear perspective: When parallel lines cover more of an area, they are far away. In the photo below, you can see the depth perception of the bridge because of how the lines are more condensed in the center of the photo. This makes us see the depth in the picture.

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Size constancy

Size constancy is how we perceive objects as having a constant size, even when we increase or decrease how far away we are from them. An example of this would be of this picture where the boy appears a lot smaller than the man that is closer up. Your brain however knows that the boy is much bigger than he appears because we perceive him as having a constant size.

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