PerceptionChapter 8, Section 3

Perception

• Allows us to confront changes in the environment; this allows us to adapt to change.

• The brain receives information from the senses and organizes/interprets it into meaningful experiences.

Gestalt•Closure: Tendency to group according to enclosed or completed figures rather than open/incomplete parts.•Continuity: Tendency to see smooth, continuous contours rather than discrete, disrupted shapes.•Proximity: Tendency to group together those elements that are close to each other.•Similarity: Tendency to group together those elements that are similar in appearance.•Simplicity: Tendency to perceive a pattern in the simplest, most organized manner-foundation of Gestalt psychology.

Figure-Ground Perception

• Ability to discriminate properly between a figure and its background.

Perceptual Inference

• When our brains “fill in the gaps” on what is missing from sensory stimuli.• Example: You hear a dog

barking, and you can deduce that it’s a dog and not a rhinoceros.

• Often depends on experience.

Learning to Perceive

• Active involvement in one’s environment is important for accurate perception.

• Influenced by our needs, beliefs, and expectations.– When we want something, we are

more likely to see it.• Perceptual Set-Prepares you to

see what you want to see. – Example: Backward Masking

Depth Perception

• Ability to recognize distances and 3D.– Develops in infancy.

• Monocular cues– Relative Height: Objects that

appear farther away from another object are higher in your plane of view.

– Interposition: Overlapping of image which causes us to view the object in its entirety to be closer.

– Light and Shadows: Brightly lit objects seem closer.

Depth Perception, (cont’d)

• Monocular cues, (cont’d)– Texture-Density Gradient: The

farther removed the object is, the less detail we can identify.

– Linear Perspective: Parallel lines converge when stretched into the distance.

– Motion Parallax (Video)

Monocular Cues

Depth Perception, (cont’d)

• Binocular cues– Convergence: Your eyes turn

inward to look at nearby objects. (Finger)

– Retinal Disparity: Each eye receiving a slightly different image. (Finger)

Constancy/Illusions

• Constancy • Illusions

– Created when perceptual cues are distorted so that our brains cannot correctly interpret size, space, and depth.• Muller-Lyer Illusion

– Two lines that have the same length appear different when “arrows” are pointed in different directions.

• Ponzo Illusion– Two lines that have the same length

appear different when placed in context with converging lines.

Muller-Lyer Illusion Ponzo Illusion