Unformatted text preview: Sensation and Perception Sensation & Perception Sensation vs. Perception Blurry baseball coming at you?? SENSATION Once you realize, interpret, the blob is a baseball ! PERCEPTION Definitions
Sensation = process by which stimulus energies are detected & encoded = processes used to arrive at a meaningful interpretation of sensations of sensations Perception organization Interpretations differ What if you were in a war zone?? would you see? What Absolute Threshold The minimum stimulation needed to detect a particular stimulus 50% of the time Subliminal Messages Messages presented below one's absolute threshold for conscious awareness Not strong enough to be recognized Subliminal Messages: Can subtly influence people, but never control behavior Experiment: on preference Sensory Adaptation Sensory Adaptation = diminished sensitivity as a consequence of constant stimulation Could you adapt to an upside down world? Photoreceptor Cells Cones Color sensitive around Concentrated fovea (the central focus on the retina) Photoreceptor Cells (cont'd) Rods Color blind Predominate in the periphery Is the eye a camera? Perception Perceptual Direct Organization (Gibson) vs Constructivist (Rock) Eye is NOT a camera Visual Capture The tendency for vision to dominate the other senses Figure Ground Perceptual Set Tendency to see one thing or the other when dealing with reversible figures Vases vs. faces Perceptual Set (cont'd) Perceptual set can be influenced by context & culture people tend to see younger woman people tend to see older person Younger Older How does the artist give illusion? Depth Perception Monocular Only Cues Binocular Use Cues use 1 eye of 2 eyes Monocular Cues Relative If Size we assume 2 objects are similar size, we perceive the one that casts the smaller image as farther away Monocular Cues (cont'd) Overlap When 1 object is partially covered by another, we perceive it as farther away Monocular Cues (cont'd) Linear We perspective/distance perceive the convergence of what we know to be parallel lines as indicating increased distance Monocular Cues (cont'd) Texture We Gradient perceive a gradual but continuous change from a coarser, more distinct, to a finer, less distinct textural element as indicating increasing distance Binocular Cues Retinal Disparity Refers to the somewhat different images our 2 eyes receive of the same object
Example: floating finger sausage Binocular Cues (cont'd) Convergence Extent to which the eyes converge inward when looking at an object Gestalt Principles of Organization Proximity Near each other, we group together (ex: 2 people on a bus--perceived as a couple who get on & off at the same stop) Gestalt Principles of Organization Similarity If similar, we group together Gestalt Principles of Organization Closure If a figure has gaps, we complete it
Cube Necker Gestalt Principles of Organization Continuity We perceive smooth, continuous patterns, not discontinuous ones Perceptual Constancy Shape Constancy
of movement, shape is still the Regardless same Example: open vs. closed door Perceptual Constancy (cont'd) Color Constancy Color looks different in different lights, but is the same Perceptual Constancy (cont'd) Size Constancy Objects/people far away--still the same size, although look smaller Contrast Effect Although they are identical, the perceived lightness of the interior rectangle differs depending on their surroundings Chubb illusion http://www.youtube.com/watch?v=vzSRVgF50 www.youtube.com/watch?v=ECeGwg7Cm0A http://www.youtube.com/watch?v=1Xm1V-9xfj http://www.youtube.com/watch?v=J5x14AwElO ...
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- Fall '08
- Psychology, Depth perception, binocular cues, monocular cues