Perceptual Constancies

Perceptual Constancies

Perceptual constancies allow us to perceive objects as unchanging even though there is a changing stimulus.

Size Constancy

With size constancy, our perceptions of the size of objects are relatively constant despite the fact that the size of objects on the retina vary greatly with distance.

This picture shows how our eyes perceive  the size of the wooden cross-braces to be the same since railroad tracks run parallel, when in the picture they are different sizes.

Brightness Constancy

Brightness constancy refers to our ability to see objects as continuing to have the same brightness even though light may change their immediate sensory properties.

In the picture above, the green pants of the person on the left look darker than the pants of the person on the right, and the grey shirt of the person on the left looks brighter than the shirt of the person on the right. This is all because the background on the left is much darker than the picture on the right.

Shape Constancy

Shape constancy helps us in perceiving the "real" shapes of objects regardless of their retinal projections. A familiar object keeps its perceived shape despite major changes in retinal stimulation due to changes in its orientation.

In this picture, all three panels are perceived to be the same shape regardless of their different drawn shape. Even the the shapes are drawn differently to give the shapes depth, we perceive them all to be the same shape.