Perceptual Constancy: Shape

Shape constancy is the ability to recognize a familiar object's constant shape even if the retinal images themselves change. The CD case above does not appear to be the same shape, but our brains recognize that the size has not actually changed.

Perceptual Constancy: Brightness

 

Brightness constancy, sometimes referred to as lightness constancy, is the ability to perceive objects at a constant lightness even when illumination varies. We are able to see the contact solution bottle as a constant shade of white in both bright, direct sunlight and a dimmed closet.

Monocular Cue: Relative Motion

 Relative motion is the monocular cue that makes it seem as though an object is moving as we are. As I move past the candle, it changes place in the frame, giving it the appearance of motion even as it remains stationary on the desk.

Perceptual Constancy: Size

Size constancy is our ability to know familiar objects as being a constant size, even if distance varies. For instance, from a foot away or from several feet away, I am still aware that my water bottle holds twenty ounces of water.

Monocular Cue: Relative Size

Monocular cues can be perceived with one eye. Relative size, the way that distant objects appear smaller, is a monocular cue. A mailbox looks smaller from several yards away.

Binocular Cue: Convergence

 

 


Binocular cues, like convergence, require both eyes to work. Convergence is the difference in direction of the eyes when we look at something close. The larger the angle, the closer the object must be, so it appears larger. Conversely, the smaller the angle, the smaller the object appears.

Motion Perception

Motion Perception: We can detect speed and direction of a moving object given visual input. In this example, all objects (girl and ball) are moving to the right. The ball has a higher velocity than the girl.