Perception The process of organizing and interpreting information, enabling us to recognize meaningful objects and events.
At any moment our awareness focuses, like a flashlight beam, on only a limited aspect of all that we experience. Inattentional blindness failing to see visible objects when our attention is directed elsewhere. Awareness Test Change blindness Change deafness NBC news clip Selective Attention Pop-out phenomenon something strikingly different & stands out.
Selective Attention: Cocktail-party phenomenon The cocktail party effect describes the ability to focus one's listening attention on a single talker among a mixture of conversations and background noises, ignoring other conversations. Form of selective attention.
Auditory Illusions If the sounds do not work click here for link.
Perceptual Illusions visual capture:when vision competes against other senses, vision usually wins. Example: watching a movie, sound coming from behind us in a theater. We perceive the people on screen as talking, making the noise, because our vision overpowers our hearing.
Perceiving Images The first step in perceiving an image is determining the figure and ground. organization of the visual field into objects (figures) that stand out from their surroundings (ground)
Gestalt and the Urge to Organize
Gestalt Psychology Gestalt psychologists focused on how we GROUP objects together. We innately look at things in groups and not as isolated elements. Proximity (group objects that are close together as being part of same group) Similarity (objects similar in appearance are perceived as being part of same group) Continuity (objects that form a continuous form are perceived as same group) Closure (like top-down processing we fill gaps in if we can recognize it) http://graphicdesign.spokanefalls.edu/tutorials/process/gestaltprinciples/gestaltprinc.htm
Motion Perception How does the brain recognize an object is moving? How does it interpret the direction of movement? Brain interprets shrinking objects as receding and enlarging objects as approaching
Stroboscopic Effect the perception of motion produced by a rapid succession of slightly varying images (animation, movies)
Phi phenomenon an illusion created when two or more adjacent lights blink on and off in succession, creating the perception of movement (lighted signs, illusions)
Perceptual Constancy the ability to perceive an object is the same even as the illumination and retinal image changes. Shape Constancy-perception that shape of an object doesn t change just because image on the retina does.
Perceptual Constancy Size constancy perception that an object s size remain the same even as the retinal image changes. Color Constancy the perception that familiar objects have a consistent color, even if changing illuminations alter the wavelength reflected.
Perceptual Constancy Lightness constancy the perception that familiar objects have a constant lightness, even while illumination varies.
Visual Cliff used to check for depth perception. (Gibson & Walk, 1960)
Depth Perception Monocular Depth Cues Linear perspective (parallel lines appears to converge on a vanishing point) Relative height (more distant objects are higher) Relative size (more distant objects are smaller)
Depth Perception Monocular Depth Cues Relative clarity (objects in the distance appear hazy) Overlap/interposition (continuous outlines appear closer)
Depth Perception Monocular Depth Cues Texture gradient (texture details, like roughness, diminish with distance)
Depth Perception Monocular Depth Cues Light and shadow
How many monocular depth cues can you identify here?
HOMEWORK: Draw a picture that incorporates at least four monocular depth cues as discussed in the book and lecture. Label the monocular depth cues in your drawing.
Depth Perception Monocular Depth Cue Motion parallax (or relative motion) Distant objects will appear slow in comparison with close objects even when the two are moving at the same speed Think of an airplane traveling overhead.
Depth Perception Binocular depth cues require two eyes Retinal disparity the greater the difference between the images on your two retina, the closer the object ( camera 1, camera 2, finger sausage, hole in the hand) Convergence the greater your eye muscles must strain (or converge) to focus on an object, the closer the object (notice how hard your eyes strain when you focus on the tip of your nose).
Size-distance relationship When other monocular cues tell us an image is further away, it actually appears larger.
Moon illusion
Perceptual Set a mental predisposition to perceive one thing and not another
What do you see?
SCHEMAS our perceptual set is developed through schemas, the concepts that we form through experiences. They help us organize our perceptions. If an atheist or Buddhist saw that wall, they d probably see nothing. A devout Christian would be more likely to see virgin mary.
FUN with Perceptual Sets -Our EXPERIENCE shapes our perceptions
FUN with Perceptual Sets -Our EXPERIENCE shapes our perceptions
FUN with Perceptual Sets -Our EXPERIENCE shapes our perceptions
FUN with Perceptual Sets -Our EXPERIENCE shapes our perceptions TIME FLIES I CANT THEYRE TOO FAST FOLK CROAK SOAK MacDonald MacHenry MacMahon Machinery
Context Effects
Extrasensory Perception Telepathy mind reading Clairvoyance perceiving remote events Precognition Knowing things before they happen Telekinesis (psychokinesis) moving objects with one s mind (not technically ESP)