Visual Illusions

Visual Illusions:

Visual illusions are the easiest way to trick the senses, as the eyes are by far the easiest sense to confuse.

WHAT DO YOU SEE?

Depending on who looks at this picture, they see different things.  Some people see a white vase, while others see two sihlouettes looking at each other.  Still others see both.


WHICH IS BIGGER?

Which of the orange circles is bigger?

ANSWER:
They are the same size.  The one on the right only appears larger because of the smaller blue circles surrounding it.

AP PSYCHOLOGY SENSORY PERCEPTION

RULES OF PERCEPTUAL ORGANIZATION

   •    Closure - This law is the illusion of seeing an incomplete stimulus as though it were whole.




We fill in the gaps to create a complete, whole object. There is no triangles or circles; our mind fills in the gaps to create a familiar shape.

   •    Continuity - this law states that patterns are perceived as smooth and continuous




Rather than perceiving three separate lines of dots meeting in the middle, we see one continuous, smooth path of dots branching out into two lines.

   •    Similarity - this law states that similar things tend to appear grouped together. Grouping can occur in both visual and auditory stimuli.





Most people see the circles and triangles as vertical columns.

   •    Proximity - this law states things that are near each other seem to be grouped together.




The birds appear to be flying together in a "V". 
* Figure-ground perception - this law states that when we view a visual image, we simplify it by separating it into figure and ground. The figure is the object you perceive. The ground is everything in the background.

In this image you either see the apple sign in white, with the black as the background. Or you see the outline of a face in black with the white as the background.

https://whatdoestayhavetosay.wordpress.com/

URLS FOR PSYCH PERCEPTION PHOTOS
   1.    http://www.ministryoftesting.com/2014/11/closure/

   2.    http://www.clevelandconsultinggroup.com/articles/emergence-gestalt-approach-to-change.php

   3.    http://www.sachsinsights.com/perception-principles-usability/

   4.    http://study.com/academy/lesson/law-of-proximity-examples-lesson-quiz.html


   5.    http://www.theinspiredeye.net/how-to-use-the-law-of-pragnanz-for-better-and-stronger-photography/

Perception Movement (stroboscopic motion)

Motion perception is the process of inferring the speed and direction of elements in a scene based on visual, vestibular and proprioceptive inputs.

 This is an example of motion perception when the stripes are visually viewed as going diagonally down toward the right, but can actually being going down or up we just can’t tell till the ends of the lines are shown

https://en.wikipedia.org/wiki/Motion_perception

Phi Phenomenon

The phi phenomenon is the optical illusion of perceiving a series of still images, when viewed in rapid succession, as continuous motion. Max Wertheimer defined this phenomenon in 1912.

https://en.wikipedia.org/wiki/Phi_phenomenon

https://www.youtube.com/watch?v=L2-swEdDXsc

In this video example you are shown multiple layering circles that form individual circles and  gives the viewers the illusion that it is moving in a spiral when in reality it is just linking.

Reversible Figures

Ambiguous images or reversible figures are optical illusion images which exploit graphical similarities and other properties of visual system interpretation between two or more distinct image forms. These are famous for inducing the phenomenon of multistable perception.

https://en.wikipedia.org/wiki/Ambiguous_image

This example shown can be viewed as two different images, one as rabbit and the other as a duck or bird,  and is an example of Reversible Figures

http://www.psy.ritsumei.ac.jp/~akitaoka/reversiblee.html

Depth Perception

Depth Perception:

Monocular Cues - 

Relative Size: When something appears to be either larger or smaller depending on its position in relation to an object of known size.

The moon appears to be larger than it is because of its position in relation to the horizon.


Relative Clarity: We percieve hazy, indistinct objects as being farther away than sharp, clear objects.

Relative Height: The height of an object reflects the perception of how close or far away it is.

Because of the positioning and differences in height in this painting, the elephant in the top right corner appears to be farther away from the viewer, even though all three were painted on a flat surface.


Monocular Cues Cont. -

Interposition: Occurs when one object overlaps another, creating what the viewer perceives as depth.

Texture Gradient:  Where there is a gradual change in detail, from highly detailed to less detailed, or vice versa


Binocular Cue -

Retinal disparity:  How your right and left eyes display slightly different images.  These then combine to form the full image that is processed by the brain.

Convergence:  In order to properly perceive depth, the eyes must move slightly inward, or converge. This enables us to be able to tell how far away something is.

Perceptual Constancies

Perceptual Constancy- enables us to perceive an object as unchanging despite a changing stimulus

Size Constancy- the tendency to perceive an object as having a constant size even while our distance from the object varies

Even though the apple appears larger than the man's head in the picture, size constancy leads us to perceive that the apple is much smaller than the man's head.

Brightness Constancy- we perceive an object as having a constant lightness even while its illumination varies

The two smaller squares appear to have the same color even though the background color is different in each larger square.


Shape Constancy- we perceive the form of familiar objects as constant even while our retinal images of them change

Both shapes are orientated differently but we know that it is the same shape.