Perception • The organization and interpretation of our sensations. It is how we create meaning for what we see, touch, hear, feel and smell.
Perception • 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.”
The Stroop Effect BlueYellowOrange Yellow RedBlackGreenRed RedGreenBlueYellowOrangeRedYellowBlack Blue Red Orange Green Blue Green Yellow
The Stroop Effect Selective Attention Theory: the interference occurs because naming colors requires more attention than reading words.
Selective Attention • Change Blindness (Person Swapping)* • Inattention Blindness*
Perception • Visual Capture:refers to the tendency for vision to dominate the other senses. Does this picture help you remember the example from your book?
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'tmttaer in wahtoredr the ltteers in a wrod are, the olnyiprometnttihng is taht the frist and lsatltteer be at the rghitpclae” …illustrates gestalt principles are at work to make things a meaningful whole.
Gestalt Principle: Mind Always Wants to Make Stimuli Meaningful.*
Gestalt Psychology • Grouping:the perceptual tendency to organize stimuli into coherent groups • Gestault/Grouping Principles: • Proximity • Similarity • Continuity • Closure • Connectedness
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)
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.
Depth Perception • Depth Perception: the ability to see objects in three dimensions. Allows us to gauge distance. • Visual Cliff Experiment: 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 to measure distance.
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
key name James J. GIBSON • Among the first to discover the importance of texture gradientfor 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.
Monocular Cue? Less detail Further away More detail Closer
Monocular Cue? Highlights and shadows can provide information about an object's dimensions and depth. Because our visual system assumes the light comes from above, a totally different perception is obtained if the image is viewed upside down.
Examples of Depth Perception • Julian Beever Chalk Drawings
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.
Poggendorf's Optical Illusion*The single line if continued joins with the _______ 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 • Perceptual Adaptation • (vision) ability to adjust to an artificially displaced visual field • prism glasses
Perceptual Set – the power of expectancy • Perceptual Set A situation where a person is predisposed (more likely) to perceive one thing over another.