| Perception: The process
of organizing and interpreting sensory information, enabling us to
recognize meaningful objects and events.
Perceptual Organization
Figure-ground Relationship: Our ability to perceive any object
(the figure) as distinct from its surroundings (the ground).
Visual Capture: The tendency for vision to dominate the other
senses when conflicting information is being received.
Gestalt Organizational Principles: Gestalt psychologists
emphasize our tendency to integrate individual pieces of information
into a meaningful whole. To bring order and form to basic visual
sensations, our brains follow certain rules for grouping
stimuli together.
1. Proximity: We group nearby objects and
belonging together.
2. Similarity: Figures similar to each other
(i.e., as in shape or color) are groups together.
3. Continuity: We perceive smooth, continuous
patterns rather than discontinuous ones.
4. Connectedness: When the are uniform and
linked, we perceive spots, lines, or areas as single units.
5. Closure: We fill in gaps to create complete,
whole objects.
Depth Perception
Visual Cliff: A laboratory device for testing depth perception in
infants. Even when coaxed, infants are reluctant to venture onto
the glass over the cliff.
Binocular Cues: Depth cues that depend on the use of both
of our eyes.
1. Retinal Disparity: By comparing the two
slightly different images received on each retina, the brain computes
the distance of what we are looking at. The greater the
disparity (difference) between the two images, the closer the
object.
2. Convergence: The extent to which the eyes
converge inward when looking at an object. The greater the
convergence, the closer the object. |
Monocular Cues:
Distance cues that require the use of one eye only.
1. Relative Size: If we assume two objects are
about the same size, the one that casts the smaller retinal image is
perceived as being farther away.
2. Interposition (Overlap): If one object
partially blocks another, the one that is partially blocked is perceived
to be farther away.
3. Relative Clarity: Because light from distant
objects must pass through more atmosphere, we perceive hazy object as
being farther away than clear, distinct objects.
4. Texture Gradient: A gradual change
from a coarse, distinct texture to a fine, indistinct texture signals
increasing distance.
5. Relative Height: We perceive objects higher
in our visual field as being further away.
6. Linear Perspective: Parallel lines (such as
railroad tracks) appear further away as they converge in the distance.
7. Light & Shadow (relative brightness): Nearby
objects reflect more light. Thus, given two identical objects, the
dimmer one seems further away.
8. Relative Motion (motion parallax): If while
riding in a train you fix your gaze on some object (the fixation point),
objects closer than the fixation point appear to be moving backward.
The nearer an object is the faster it seems to move. Objects
behind the fixation point appear to be moving with you: The farther away
the object is from the fixation point, the more slowly it appears to
move.
Motion Perception
One way we perceive motion is by knowing that if an object keeps
getting bigger, it is probably moving towards us. If an object is
shrinking, it is moving away from us.
Phi Phenomenon: When two or more adjacent stationary lights blink
on and off in quick succession, we perceive a single light moving.
(Lighted signs use this phenomenon).
Stroboscopic Movement: The brain will interpret a rapid series of
slightly varying images as continuous movement. By flashing 24 still
pictures each second, a motion picture creates perceived movement.
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