Perceiving objects as unchanging (having constant lightness,
color, shape, and size) even when our retinal images of them change.
Shape Constancy: We perceive the form of familiar objects as
constant even when our retinal images of them change.
Size Constancy: We perceive familiar objects to maintain a
constant size even when their distance from us changes.
Lightness Constancy: We perceive an object as having a constant
lightness even when its illumination varies.
Some Visual Illusions
The Ponzo Illusion (in two forms)
The Ames Room
**Please see your textbook for explanations of these illusions.
People blind from birth, who later have their vision restored,
can distinguish figure-ground relationships, can sense colors, but have
great difficulty recognizing objects that they were familiar with by
|Similarly, Blakemore & Cooper
found that kittens whose vision was restricted to only seeing vertical
lines during a critical period of development, later could not
see horizontal lines.
Perceptual Adaptation: In vision, the ability to adjust to an
artificially displaced or even inverted visual field.
Perceptual Set: A mental predisposition to perceive one thing and
not another (e.g., seeing the Lock Ness Monster instead of a piece of
driftwood because of your beliefs).
Context Effects: Any given stimulus may trigger radically
different perceptions depending on the surrounding environment or
circumstances. Culture may have a great impact on context and
Human Factors Psychology: A branch of psychology
that explores how people and machines interact and how machines and
physical environments can be adapted to human behaviors.
Extrasensory Perception (ESP)
The controversial claim that perception can occur apart from
Telepathy: Mind to mind communication
Clairvoyance: The sensing of remote events that are presently
Precognition: The sensing of future events.
Telekinesis (psychokinesis): Ability to affect objects with the
power of the mind.
Parapsychologists: Psychologists who study paranormal occurrences,
including claims of ESP.