Perception

Perception The organization and interpretation of our sensations. It is how we create meaning for what we see, touch, hear, feel and smell.

Bottom-up Processing Analysis of the stimulus begins with the sensory receptors and works up to the level of the brain and mind. Letter “A” is really a black blotch broken down into features by the brain that we perceive as an “A.”

Top-Down Processing Information processing guided by higher-level mental processes as we construct perceptions, drawing on our experience and expectations. Top Down Processing explains how our expectations and prior experiences guide our perceptions. THE CHT

Top-Down Processing Aoccdrnig to rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.

How many faces do you see? Making Sense of Complexity “The Forest Has Eyes,” Bev Doolittle

Selective Attention: the idea that we are only aware of a small percentage of what we experience.

Selective Attention The most famous example to illustrate selective attention is known as the “cocktail party effect.”

Red Green Blue Yellow Orange Red Yellow Black Blue Red Orange Green Blue Green Yellow Blue Yellow Orange Yellow Black Green Red Red The Stroop Effect Try to read the COLOR of the words!

The Stroop Effect Selective Attention Theory: the interference occurs because naming colors requires more attention than reading words.

Perception Visual Capture: refers to the tendency for vision to dominate the other senses.

Perceptual Organization Gestalt: an organized whole. Gestalt psychologists emphasize humans’ tendencies to integrate pieces of information into meaningful wholes. Things are not seen as sum of parts but immediately as wholes.

Gestalt Principle: Mind Always Wants to Make Stimuli Meaningful. The fact that you can read this sentence… “it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprometnt tihng is taht the frist and lsat ltteer be at the rghit pclae” …illustrates gestalt principles are at work to make things a meaningful whole.

Gestalt Psychology Grouping: the perceptual tendency to organize stimuli into coherent groups Gestalt/Grouping Principles: ◦ Proximity ◦ Similarity ◦ Continuity ◦ Closure ◦ Connectedness

Proximity: tendency to group nearby figures together

Similarity: tendency to group figures that are similar

Continuity: tendency to perceive continuous patterns

Closure: tendency to fill in the gaps in visual information.

Connectedness: spots, lines and areas are seen as a unit when connected

Perceptual Organization Figure-Ground Relationship: tendency to organize information into objects (figure) that stand out from their background(ground)

Figure Ground Illusion

The Big Ten collegiate conference has eleven schools but they didn’t want to change their name. However, they used their logo to hide the numerical “11” in the name.

I never noticed the brilliant logo until recently. You must be thinking what is there to find out as it clearly shows the Swiss Alps? Let me explain…Toblerone originated in Bern, Switzerland - A city whose name is rumored to mean, “City of bears.” When you look at it again you will find a bear in the logo. Toblerone Chocolate

It’s a really good zoo and the logo is pleasant. However, it becomes an awesome logo when you see the animals in the white space on the left and right sides of the tree. Pittsburgh Zoo

The most famous bicycle race in the world has a beautiful logo that becomes more impressive when you finally perceive the bicycle rider on the right side. Tour de France

Depth Perception Depth Perception: the ability to see objects in three dimensions. Allows us to gauge distance. Visual Cliff: illustrated that crawling infants and newborns perceive depth.

Types of Depth Perception Binocular Cues: depth cues that rely on the use of two eyes. Examples of Binocular Cues: ◦ Retinal Disparity: idea that images of an object from the two eyes differ. The closer the object, the larger the difference (disparity.) ◦ Convergence: extent to which the eyes converge inward when looking at an object that brain keeps track of in order to measure distance.

Retinal Disparity and the Sausage Illusion

Types of Depth Perception Monocular Cues: distance cues that are available to either eye alone. Often used in art. Examples of 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

James J. GIBSON James J. GIBSON Among the first to discover the importance of texture gradient for perceiving depth. Most surfaces have a texture but it becomes less detailed as the surface recedes into the background.

Types of Depth Perception Examples of Monocular Cues Continued: ◦ 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 ◦ Light and Shadow: nearby objects reflect more light to our eyes.

Monocular Cue? Who is closer: Snoopy or Woodstock? Woodstock How do you know? Woodstock blocks part of Snoopy. In other words, INTERPOSITION.

More detail Less detail Closer Further away Monocular Cue?

Real Quick: Phi Phenomenon Motion Perception: Illusion of Movement with Blinking Lights

Perceptual Constancy Perceptual Constancy: perceiving objects as unchanging despite changes in retinal image  shape  size

Interplay Between Perceived Size and Distance Using monocular cues for distance can often cause us to perceive incorrect information.

Muller-Lyer Illusion Involves Misperception of Line Segments

Poggendorf's Optical Illusion* The single line if continued joins with the _______ line.

Poggendorf's Optical Illusion* The single line if continued joins with the red line. One explanation for this illusion is that the lower right end of the line appears nearer than the upper left; that is, the line is seen as receding in space.

Sensory Deprivation and Perception Kittens raised without exposure to horizontal lines later had difficulty perceiving horizontal bars. Remember that sensory deprivation affects infants worse than older animals and humans.

Perceptual Adaptation ◦ (vision) ability to adjust to an artificially displaced visual field

Perceptual Set – the power of expectancy Perceptual Set A situation where a person is predisposed (more likely) to perceive one thing over another.

Perceptual Set

Usually See Saxophone Player Now Instead of…

Woman

Illusions Videos Auditory: hWXRWU hWXRWU Visual: ◦ 2R-8

Is there Extrasensory Perception? Extrasensory Perception: claim that perception can occur apart from sensory input. ◦ Telepathy ◦ Clairvoyance ◦ Precognition Parapsychology: study of paranormal phenomenon, including ESP and psychokinesis.