We do not perceive the world how it really is, but as it is useful for us to perceive it.

Perception The process of organizing and interpreting information we get from our senses enables us to recognize meaningful objects and events. In transforming sensations into perceptions, we create the meaning

Selective Attention Any moment we focus our awareness on only a limited aspect of all that we experience Example– directions video

Cocktail Party Effect Ability to attend selectively to only one voice among many

Visual Capture The dominance of vision over other sense modalities, such that what is felt or heard conforms to what is seen.

Perceptual Illusions Once we have attended to certain stimuli, how do we organize them into meaningful perceptions?

Dalmatian Picture

Perceptual Illusions

Visual Capture When vision competes with other senses, vision usually wins- known as visual capture For example- watching a movie, in theatres we believe the sound is coming from the screen where people are talking, when really, it’s not

Perceptual Organization To transform sensory information into meaningful perceptions, we must organize it We must perceive objects as distinct from their surroundings, see them as having a meaningful and constant form, and discern their distance and motion.

Gestalt German scientist became intrigued with how the mind organizes sensations into perceptions Given a cluster of sensations, the human perceiver organizes them into a gestalt Described principles by which we organize our senses into perceptions

Gestalt Psychology Gestalt means “an organized whole” These psychologists were concerned with how and why we GROUP objects together. They stated that humans can not help but perceive stimuli in groups rather than individual or isolated elements This explains why we see a cube and not a set of isolated holes or circles

Perceptual Organization: Gestalt  Grouping  the perceptual tendency to organize stimuli into coherent groups  Grouping Principles  proximity--group nearby figures together  similarity--group figures that are similar  continuity--perceive continuous patterns  closure--fill in gaps  connectedness--spots, lines, and areas are seen as unit when connected

PerceptualOrganization: Grouping Principles

Proximity We group nearby figures together.

Proximity Grouping nearby figures together 3 sets of parallel lines not six separate lines

Similarity Figures similar to each other we group together.

Similarity Grouping together figures that are similar to each other 9 separate shapes Or Two columns and one Column?

Continuity We perceive smooth, continuous patterns rather than discontinuous ones

Continuity Perceiving smooth continuous patterns not discontinuous ones

Connectedness When they are uniform and linked, we perceive spots, lines, or areas as a single unit

Perceptual Organization: Closure  We fill in gaps to create a complete, whole object

Closure Filling in gaps to create a complete, whole object

Perceptual Organization  Figure and Ground--organization of the visual field into objects (figures) that stand out from their surroundings (ground)

Warm-Up 1.What is perception? 2.Give an example of bottom-up processing 3.Explain Gestalt Psychology and give one example of grouping. 4.Explain Cocktail Party Effect

Perception Our perceptions are affected by the biology of our sensory systems, but also by our previous experiences and cultural expectations. Or in other words our… Schemas

Take a moment to write down a few adjectives to describe each person based on their pictures. AB

Which one is better looking?

Perception is also often based on… Perceptual Set Perceptual Set A bias to perceive one thing and not another when looking at things in our world A bias to perceive one thing and not another when looking at things in our world Sort of the same thing as a mental set Sort of the same thing as a mental set So in some ways it can cause us to make errors in judgments when we are trying to perceive the world through our senses So in some ways it can cause us to make errors in judgments when we are trying to perceive the world through our senses

What you see in the center is influenced by your perceptual set What do you see?

Perceptual Set Bill Clinton and who?

Perceptual Set-Schemas Which is the real Madonna?

Perceptual Set-Schemas When we hold the eyes as a constant it is difficult to identify the correct Madonna. Now that the image is rotated it is easy to tell the difference.

Perceptual Illusions Used to reveal how we normally organize and interpret sensations Used to reveal how we normally organize and interpret sensations Optical or Visual Illusions Optical or Visual Illusions Discrepancies between the appearance of a visual stimulus and its physical reality Discrepancies between the appearance of a visual stimulus and its physical reality

Form Perception Figure-Ground Relationship When we look at objects we see the object as the figure and its surroundings as the background –Airplane in the sky

Depth Perception  The ability to see objects in three dimensions although the images that strike the retina are two dimensional.  Allows us to judge distance.

Perceptual Organization Depth Perception Visual Cliff Used to test infants depth perception

How do we transform two- dimensional objects to three- dimensional perception?  Binocular Cues: depth cues that depend on two eyes depth cues that depend on two eyes Monocular CuesMonocular Cues: depth cues that depend on one eye

Perceptual Organization: Depth Perception  Binocular cues  retinal disparity  images from the two eyes differ  closer the object, the larger the disparity  convergence  neuromuscular cue  two eyes move inward for near objects

Perceptual Organization: Depth Perception  Monocular Cues  relative size  smaller image is more distant  interposition  closer object blocks distant object  relative clarity  hazy object seen as more distant  texture coarse --> close fine --> distant

Perceptual Organization: Depth Perception  Monocular Cues (cont.)  relative height  higher objects seen as more distant  relative motion  closer objects seem to move faster  linear perspective  parallel lines converge with distance  relative brightness  closer objects appear brighter

Linear Perspective Parallel lines seem to converge with distance.

Linear Perspective at Work

Relative Size if we know that two objects are similar in size, the one that looks smaller is farther awayRelative Size if we know that two objects are similar in size, the one that looks smaller is farther away Relative Size

Interposition if something is blocking our view, we perceive it as closer

Motion Perception What tools do we use to perceive motion…  Stroboscopic movement Perceiving continuous movement Perceiving continuous movement Example Example MoviesMovies Flip Book Example

Phi Phenomenon An illusion of movement created when two or more adjacent lights blink on and off in succession.

Cataracts Definition: an eye disease in which the lens becomes covered in an opaque film that affects sight, eventually causing total loss of sight.

ESP Three types of ESP: 1.Telepathy- mind to mind communication 2.Clairvoyance- perceiving events as they are taking place 3.Precognition- perceiving future events Also associated with ESP, psychokinesis (“mind over matter”