Chapter 5 Flashcards
what makes a human different from machines?
humans can detect unclear images in their visual receptors (inverse projection problem)
humans can identify hidden or blurry objects
humans know that objects remain the same even at different angles (viewpoint invariance)
inverse projection problem
retina in humans can determine what an object represents even if it doesn’t look like the object in the retina
viewpoint invariance
ability to recognize an object from different viewpoints (object stays the same no matter the orientation)
perceptual organization
how we process elements/objects of an environment in our visual system
2 components: grouping and segregation
grouping
component of perceptual organization
objects belonging together
segregation
component of perceptual organization
objects separate from each other
structuralism
type of perceptual approach
build up sensory parts first and perception will occur
past experiences can influence building sensations to form perception
Gestalt approach
type of perceptual approach
past experience plays minor role
“whole is different than the sum of its parts” – perception does not always require adding up sensations first
apparent movement
illusion of movement when nothing is movement
relating to gestalt approach; structuralist cannot explain building up sensations to form movement (can’t see it but you know)
illusory contours
appearance of shape without actual physical edges present
relating to gestalt approach; structuralist cannot explain how sensations are built up without physical edges to perceive shape
7 gestalt organizing principles of perception
good continuation (connecting points of straight lines or smooth curves are grouped together)
pragnanz (pattern interpreted in simplest way possible)
similarity (alike items grouped together)
proximity (things near each other are grouped together)
common fate (things moving in the same direction are grouped together)
common region (elements in same area are grouped together; can overpower proximity)
uniform connectedness (connected region perceived as single unit; can overpower proximity)
perceptual segregation
how an element can be separated from another element
ex. figure-ground segregation
Vecera et al experiment
focus: detect where people perceive figure and ground
up-down display (lower area = figure; above area = ground)
left-right display (no preference of figure and ground)
^^because of everyday awareness (below area = land = figure ; above area = sky/background = ground)
Peterson and Salvagio experiment
left-right display (convexed borders – the ones bulging out – tend to be figure)
if left-right display is more focused, this will not always be the case because of contextual cues and segregation
what do gestalt psychologists believe regarding perceptual organization and experiences in recognizing objects
perceptual organization could override past experiences to recognize objects
Gibson and Peterson experiment
meaningfulness can play an important role in recognizing objects
familiarity allows people to recognize patterns of an object
recognition by components theory
biederman (Supporting idea of viewpoint invariance)
objects are composed of geometric components called geons (3D shapes)
limitation: not all geons are shaped the same way for objects (ex. clouds)
scene
view of the environment
contains:
background elements
objects organized in meaningful ways with each other and the background
how do objects differ from scenes
object: acted upon (involves action to an object)
scene: acted within (environment where action of object occurs)
gist of a scene
how we generally describe our rapid awareness of the environment
how long can a person perceive the gist of a scene
250 ms
visual masking
important for covering info from being seen after stimulus is shown
prevents persistence of vision (perception lasts for another 250 ms when image disappears)
global image features (5 features)
characteristics we use to rapidly perceive specific types of scenes
degree of naturalness (natural scenes = textured, wavy ; man-made = straight)
degree of openness (spacious and contains few objects)
degree of roughness (how smooth looking environment looks)
degree of expansion (convergence of parallel lines show distance)
color (colors can depict a certain type of scene)
physical regularities
semantic regularities
Palmer’s experiment
items that fit scene schema were identified more accurately than those that did not fit context
helmholtz’s theory of unconscious inference
our unawareness of being able to interpret a stimulus in more than one way in the environment
likelihood principle
objects perceived based on what is most likely to have caused the pattern
