Unit 4: Perceptual Organization & Interpretation

Perceptual Organization We have looked at how we perceive the world around us with our senses But how do we make sense/meaning out of all of it? The answer is perceptual organization In the early 20th century, psychologists notice how people form groups with several stimuli, and organized them into a gestalt A gestalt is a “whole” or a “form”

We create gestalts to make fragments meaningful We use several techniques to organize groups of stimuli into something useful, so that we can then understand and interpret Figure-Ground: when first looking at a stimuli, we must first perceive a figure from its surrounding in order to make it meaningful

Grouping: this is an automatic technique that forms stimuli into groups Proximity Similarity Continuity Connectedness Closure

Closure Similarity

Depth Perception Depth Perception: since we have two eyes, we have different ocular cues that allow us to see the world in three dimensions One way our depth perception is tested is with a visual cliff experiment Binocular cues: these are depth cues, like retinal disparity, that depend on the use of two eyes Retinal disparity: using both retinas to compare an image we know the distance, the greater the disparity between two images, the closer the object

Monocular cues: only need one eye to perceive these. Relative height Relative size Light & shadow

Motion Perception ·        Motion Perception: we perceive motion through two basic principles: something leaving is shrinking in size, something approaching gains in size The brain also perceives rapid, continuous, movement, in a series of images as motion, stroboscopic motion Some signs also use the phi phenomenon, blinking lights creating the illusion of movement

Perceptual Constancy This function allows us to see stimuli as unchanging, which is part of top-down processing Shape constancies: an object does not change actual shape, but can be perceived to as we change angles. Size constancies: we have a constant size perception, even when the distance varies, manipulating the size to our eyes

Lightness constancies: we perceive an object to have constant light reflection, no matter the illumination Color constancy: perceiving familiar objects to have consistent color, despite the changing illumination

Perceptual Interpretation Since top down processing involves us to perceive things from our experiences, how can this change how we perceive the world around us? A case of sensory deprivation & restored vision can help “Can someone born blind, distinguish between a sphere and a cube if they had their vision restored?” The answer is no, but we are born with some ability to perceive certain colors and distinguish between figures and ground.

Perceptual Adaptation: with our vision, we have the ability to adjust to an artificially displaced vision field. (Why is this important?)

Perceptual Sets: this is a mental pre-disposition that greatly influences how we perceive something Context Effects: Our perception can be greatly influenced on context Emotions/Motivations: perceptions are also influenced top-down by our emotions and motivations

Cultural Impacts On your paper, think for a minute and come with a few ideas, as to how culture can impact our perceptual sets, thereby our top-down processing.