Perception crash course The process of organizing and interpreting information, enabling us to recognize meaningful objects and events. Seeing the world as it isn't

Moon Illusion Naturally occurring optical illusion in which the moon appears larger on the horizon than it does higher up in the sky.

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Perceptual Ideas Perceptual set: a mental predisposition to perceive one thing and not another.

Top-Down Processing We perceive by filling the gaps in what we sense. I _ant ch_co_ate ic_ cr_am. Based on our experiences and schemas. Perceptual Set – a mental predisposition; the experiences, assumptions, and expectations that influence our perception

Context Effects Based on immediate context, not schemas (your personal framework for understanding and organizing information). You do not hear the word, but can guess at it based on the context it was said in.

The Muller-Lyer Illusion Both parallel lines are equal lengths.

The Muller-Lyer Illusion

Cultural Influences in Susceptibility Studies have discovered that people in non-Western cultures are less susceptible to the Muller-Lyer Illusion than Western samples. The most plausible explanation is that in the West we live in a “carpentered world” dominated by straight lines, right angles and rectangular rooms. Thus our experience in the Western world readily prepares us to view the Muller-Lyer Illusion as inside and outside corners of buildings. In contrast, people in some non-Western cultures who live in less “carpentered worlds” are less prone to see the Muller-Lyer as building corners.

Perceptual Adaptation inverted vision program 7: start @ 15:39 The ability to adjust to an artificially altered visual field

Are the red lines parallel??? http://www.michaelbach.de/ot/

Gestalt Psychology Gestalt – an organized whole; from German for “form” or “whole” Gestalt psychologists emphasized the tendency to integrate pieces of information into a meaningful whole. Gestalt Psychology says that we innately look at things in groups, not as isolated elements. “The whole is greater than the sum of its parts.”

Grouping & Gestalt Psychology Khan Academy 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 Connectedness – objects that are uniform and linked are perceived as single units Closure - we fill gaps to create a whole or complete image Closure

Figure Ground Relationship Visually, our first perceptual decision is “What is the figure?” in the image and “What is the ground?” (background). The figure ground relationship can also be applied as a principle of auditory perception.

Depth Perception Eleanor Gibson - Visual Cliff Experiment If you are old enough to crawl, you are old enough to see depth perception. Modern Version We see depth by using two cues that researchers have put in two categories: Monocular Cues Binocular Cues

Sensory Restriction Blakemore & Cooper, 1970 Kittens raised without exposure to horizontal lines later had difficulty perceiving horizontal bars. Footage

Binocular Cues Khan Academy We need both of our eyes to use these cues. Retinal Disparity - as an object comes closer to us, the differences in the images for our eyes becomes greater. “finger sausage” 3-D movies Convergence - as an object comes closer, our eyes have to come together to keep focused on the object

Monocular Cues khanacademy(start 2:00) You really only need one eye to use these (used in art classes to show depth). Linear Perspective Interposition Relative Size Texture Gradient Light / Shadowing

Depth Perception – Monocular Cues Relative Size – if we assume that two objects are similar in size, we perceive the one that casts the smaller retinal image as farther away

Depth Perception – Monocular Cues Interposition – if one object partially blocks our view of another, we perceive it as closer.

Depth Perception – Monocular Cues Relative clarity – because light from distant objects passes through more atmosphere, we perceive hazy objects as further away than sharp, clear objects.

Depth Perception – Monocular Cues Texture gradient – a gradual change from a coarse, distinct texture to a fine, indistinct texture signals increasing distance

Depth Perception – Monocular Cues Relative height – we perceive objects higher in our field of vision as farther away; lower in the field as closer

Depth Perception – Monocular Cues Linear perspective – parallel lines appear to converge with distance

Depth Perception – Monocular Cues Light and shadow – nearby objects reflect more light to our eyes; given two identical objects, the dimmer ones seems farther away

Motion Perception Relative motion (motion parallax)– as we move, objects that are actually stable may appear to move Objects closer than the fixation point appear to move backward and faster. Objects beyond the fixation point appear to move with you and slower.

Motion Perception We tend to perceive that shrinking objects are retreating and enlarging objects are approaching. We tend to perceive that larger objects more move slowly than smaller objects.

Motion Perception Stroboscopic Effect Phi Phenomenon a rapid series of slightly varying images perceived as moving images (flip book, “old” movies) Phi Phenomenon illusion of movement created when two or more -----lights next to each other blink on and off

Constancy an illusion Shape Constancy Size Constancy Color Constancy Objects change in our eyes constantly as we or they move….but we are able to maintain content perception Shape Constancy Size Constancy Color Constancy Brightness Constancy However, color and brightness also depends on context!

Parapsychology Parapsychology: the study of paranormal phenomena Extrasensory Perception (ESP): claim that perception can occur apart from sensory input. Includes: 1. telepathy: communication by perceiving another’s thoughts 2. clairvoyance: perceiving remote events (those happening elsewhere) 3. precognition: perceiving future events before they happen Closely linked to ESP is telekinesis: the ability to move objects with the mind.