Perception The process of organizing and interpreting information, enabling us to recognize meaningful objects and events.

Our individual perceptions are not the same. Even though, we are all exposed to the same sensations, our perceptions are so different due to: Our experiences (schemas) Our eyesight, our hearing abilities Our culture Our personalities Our expectations

Our Perceptual Ideas Guide our behavior

Bottom-Up Processing Processing incoming stimulation (or feature analysis). We use the features on the object itself to build a perception. When we engage our brain, we have to use brain trick to process quickly. We fill in gaps, we group things, we see depth and motion, and use our expectations.

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. What do you see? If you are exposed to many old men in glasses, that’s what you will see when you are exposed to an ambiguous images, when you see several mouse images, you will see the image as a mouse.(your expectation).

How do we organize what we see? Gestalt Psychology: ( an alternative to Wilhelm Wundt’s approach of breaking conscious experience into its most fundamental components) - stated breaking experiences into their basic parts looses something important. Instead the gestalt (or whole) may be greater than the sum of its parts.

We don’t focus on individual stimuli but we group in an effort to understand the world around us. Our brain has to take in this information very quickly, so it has some rules to do this.

We innately look at things in groups and not as isolated elements. Figure Ground Relationship. Our first perceptual decision is what is the image(figure) and what is the background?

What do you see?

The tendency to perceive figure and ground is not exclusively visual. We strive to identify “the figure” in other contexts as well, such as the predominant taste in a casserole or The melody of a song.

Grouping principles Proximity (group objects that are close together as being part of the same group) Similarity (objects similar in appearance are perceived as being part of the same group) Continuity (objects are perceived as same group if it looks like it continues on) Closure or Connectedness (like top-down processing…we fill gaps in if we can recognize it)

Continuity Responsible for car wreck at night. Where object appears to move in a particular direction, your brain assumes that the movement continues unchanged. Detours not marked very well. We assume the highway continues in the direction we’ve been moving. Of course, there may be other distractions involved but that’s really important for this perceptual tendency.

Closure is used in advertising to save money or for interest, can you think of some ways?

One other grouping principle: Contiguity The tendency to perceive two things that happen close together in time as being related. Usually the first occurring event is seen as causing the second event. Another name is illusory correlation ubmit=Submit ubmit=Submit sometimes used in social psychology. Where a relationship is perceived when actually there is none. Ex. How I fixed my kitchen drawer with a flash light.

What is depth perception and how does it affect our lives? The ability to see in three dimensions and judge distance. Another survival skill of perception. Visual cliff – a laboratory device for testing depth perception in infants and young animals.

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

Binocular Cues We need both of our eyes to use these cues. Retinal Disparity (as an object comes closer to us, the differences in images between our eyes becomes greater. Convergence (as an object comes closer our eyes have to come together to keep focused on the object).

Viewmaster – two identical pictures slightly apart D+images&view=detail&id=9FA7DF772B53A097FA446EE68708D2EFDD188220

Stereogram – the ability to see an image in the picture - Happy cat

Monocular Cues You really only need one eye to use these (used in art classes to show depth). Linear Perspective Interposition Relative size Texture gradient Shadowing

Phi phenomenon – fixed object turned on and off and Stroboscopic motion - seeing a series of slightly varying figures Motion Perception: What might cause us to perceive motion when nothing is moving?

Perceived Motion Stroboscopic effect (flip book effect) Phi phenomenon Autokinetic Effect (if people stare at a white spotlight in a dark room, it appears to move.)

8.2 What are perceptual constancies, and why are they important? Size constancy is the tendency to perceive objects as remaining the same size. Shape constancy is the tendency to perceive objects as remaining the same shape. Brightness constancy is the tendency to perceive objects at a certain brightness.

Constancy Objects change in our eyes constantly as we or they move….but we are able to maintain content perception Shape Constancy Size Constancy Brightness Constancy

Perceptual Set- pg 196 We see what we expect to see. Confirmation bias.

Face Schemas

How does context influence our perceptions ? Context effects – when we see something out of context, it may be distorted.(teacher at the mall) The setting or environment in which we interpret sensory stimuli affect what we perceive.

Illusions: When we are tricked into misinterpreting sensory stimuli.

illusions are perceptions that do not correspond to reality. or they are distortions of visual stimuli. We study because they provide clues about how our sensory and perceptual systems work. Psychologist study because it behavior that is supposed to work one way, but it does not work right. Why? How do visual illusions work? Examples: include the Müller-Lyer illusion :