Phi Phenomenon

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The Phi Phenomenon is an illusion of movement created when two or more adjacent lights blink on and off in quick succession.  An example of this is two pictures flashing on a screen, one after another.  You would view these two pictures as having motion and moving between one another, but in fact they are stationary.   This example is presented in this post's accompanying graphic.

Perception of Movement

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Perception of movement, or stroboscopic motion, is a perceptual phenomenon in which an appearance of motion (or lack of motion) occurs when the stimulus is not viewed continuously but in distinct separate stages.  An example of this would be a GIF, which is multiple still images played in succession to create an illusion of motion, as can be seen in our graphic for this post.

Rules of Perceptual Organization- Figure-Ground Perception

A final rule of perceptual organization is figure-ground perception.  This rule states that the eye differentiates an object from its surrounding area.  An example of figure-ground perception would be the Pittsburgh Zoo logo.  You can view both the image of two trees and of two animals facing each other when you view this logo, with your brain often alternating between the two.

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Rules of Perceptual Organization- Similarity

A third rule of perceptual organization is similarity.  This rule states that we group together figures that are similar to each other.  One example of this would be the Health Unlimited logo.  In this example similar shapes and the solid black causes our mind to view the logo as a whole.

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Rules of Perceptual Organization- Contiunity

Another rule of perceptual organization is continuity.  This rule states that we perceive smooth, continuous patterns rather than discontinuous ones.  One example of this would be the Adidas logo.  In this famous logo we view the three lines as a whole, rather than as three separate lines.  This is because viewing the lines as a whole is smoother and more continuous than three sepearte broken lines.

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Rules of Perceptual Organization- Closure

One rule of perceptual organization is closure.  This rule states that we fill in gaps to create a complete, whole object.  One example of this would be the World Wildlife Fund's logo, which is an incomplete design viewed as one complete object, as is shown in this post's accompanying picture.

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Rules of Perceptual Organiation- Proximity

A fourth rule of perceptual organization is proximity.  This rule states that we group nearby figures together.  One example of this would be the Unilever logo.  Proximity can be seen in the way that you view the logo as a single "U", when it is in fact a combination of many smaller figures.

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Visual Illusions- images or photographs that are perceived differently than they actually are. The eyes send information to the brain which fools one into seeing and perceiving something that does not line up with reality
Examples- 1. This images appears to be moving, regardless of the fact that it is just an illustration
http://www.funnyzone.org/optical-illusions/3d-wave-optical-illusion/

2. This illustration tricks the brain because it is difficult, if not impossible, to find the outlines of all of the legs. Rather, they blend into one another, creating a visual illusion.
http://sharpbrains.com/blog/2010/10/27/test-your-brain-with-these-top-10-visual-illusions/

3. This illusion tricks the brain because it is difficult to tell whether the cube in the middle is a cube coming out or a space going in, again, making this drawing a visual illusion.

Relative Height-objects that are higher in one's field of vision are perceived as farther away while lower ones are perceived as closer. This may be related to the perception that vertical dimensions are longer than horizontal ones of the same length.
Example: The farmhouse in this drawing appears as farther away than the ducks because it is smaller than them
http://becuo.com/monocular-cues-relative-height

Relative Clarity: on perceives objects as farther away, if the appearance of them is made hazy (like fog, smoke, or snow), because light from objects in the distance pass through more atmosphere, which is also why clear objects are seen as closer than their hazy counterparts

Example: This clear, focused flower in the center of the image seems closer than the blurry flowers behind it, due to relative clarity
http://imgarcade.com/1/relative-clarity-psychology/

Monocular Cues- these visual cues only require the use of one eye, and using these different cues can help one determine characteristics such as the motion of an object, as well as its size and shape.

Relative Size- if it is perceived that two objects are closely related in size, it is perceived that the object giving off a smaller image formed on the retina is farther away.

Example: In the photograph below, these two horses are presumed to be the same size, but the horse with the black spots is smaller in the photo because it is farther away from the camera than the horse with brown spots. Thanks to relative size, one can perceive that the black horse is simply farther away rather than thinking that it is a very small horse standing right next to horse with brown spots.
https://www.flickr.com/photos/skarpi/5472158415/

Reversible Figures- these are illustrations that are drawn in a way that they can be seen by two different perspectives, appearing to be two different things
Example: The illustration below can either look like a vase (the black outline in the center) or two faces looking at each other (the white space on either side of the drawing)
 http://department.monm.edu/chemistry/honors210/fall2005/ncarlson/Topic_Presentation_3.htm

Shape Constancy - Objects that are viewed from different angles will produce different shapes on our retinas, but we know that the shape of an objects remains constant.
example: In this image, coins are shown from different angles but we know that in each picture there is a coin being represented, and we know that in real life the shape of each image of a coin would be circular.

Brightness Constancy - We perceive objects as being a constant color even as the light reflecting off of the object changes.
example: Even though there are different types of light reflected on each image of the bowl of fruit, we perceive them all as being the same colors.

Size Constancy - This causes us to perceive objects as maintaining a constant size, even when the distance we are from them varies.
example: Even though one of the canoes is further away in this photo than the other and as a result is smaller in the photo, size constancy allows us to be able to realize that they would both be the same size when placed at the same distance from our eyes.

Binocular cue - Depth cues, such as retinal disparity and convergence, that depend on the use of two eyes.
example: The retinas of both eyes have to work together while sending messages to the brain because of the differences in images.

Retinal Disparity - The differences between the images perceived by the retina of each eye, which provides an important cue to the relative distance of different objects.

example: As you can see in this image, the left eye shows the man further back as being in a different position relative to the man in the front.

Convergence - A neuromuscular cue caused by the eyes' greater inward turn when they view a near object.

example: The bug on the nose of the person in this image is very close to his eyes, causing convergence to occur in order to make the image clear.

Monocular cues (con't): depth cues available to either eye or alone.

interposition - If one object partially blocks the view of another, we perceive it as being closer. This causes depth perception.
example: a cube drawn like this causes the lines to appear to create a cube because the lines are different colors and they look as though they blend together.

texture gradient - A gradual change from a coarse, distinct texture to a fine, indistinctive texture, signaling increasing distance.
example: the squares in this image are different shapes and sizes, creating a three dimensional look and a larger distance across the image.


linear perspective - This takes place when parallel lines appear to converge with distance. The more  they converge, the greater the distance they are perceived becomes.
example: the lines that make up this railroad in real life are parallel, but the photo makes is seem like they are converging into the distance, making the distance seem farther.