Chapter 5

Question 1

inverse projection problem

Answer 1

task of determining object responsible for a particular image on retina. Involves starting with retina and extending rays out to object

Question 2

viewpoint invariance

Answer 2

ability to recognize an object seen from different viewpoints

Question 3

perceptual organization

Answer 3

process by which elements in our environment become perceptually grouped to create our perception of objects

Question 4

grouping

Answer 4

process by which visual elements are put together into units or objects

Question 5

segregation

Answer 5

process of separating one area or object from another

Question 6

gestalt

Answer 6

configuration “how are configurations formed from smaller elements?”; Gestals psych rejected “adding up” and experience

Question 7

structuralism

Answer 7

pre-Gestalt - Wundt, Leipzig 1879; distinguished between sensations (elementary processes that occur due to stimulation of senses analagous to atoms of chemistry) and perceptions (complex conscious experiences such as awareness of an object); combination of sensations that form perceptions influences by past experiences

Question 8

illusory contours

Answer 8

pac man - triangle observed, no edges present, can not be explained by sensation because no sensation along contours

Question 9

apparent movement (stroboscope)

Answer 9

wertheimer - how could the illusion be saw be created from sensations? movement can be explained by perceptions due to dark portion, whole is different than the sum of parts; movement perceived but not real 1) image flashes on and off, 2) period of darkness (franction of a second), 3) 2nd image flashes on and off - perceptual system adds image of movement during period of darkness

Question 10

organizing principles

Answer 10

Gestalt principles - determine how elements in a scene are grouped

Question 11

Principle of good continuation

Answer 11

pts that when connected result in straight/smooth lines are seen as belonging together and tend to be seen in the way that follows the smoothest path (surfaces too - partially obscured objects seen as continuing beyond cover)

Question 12

Pragnaz, principle of good figure/simplicity

Answer 12

every stimulus is seen in a way that resulting structure is as simple as possible

Question 13

principle of similarity

Answer 13

similar things appear to be grouped together

Question 14

principle of proximity/nearness

Answer 14

things that are near each other appear grouped together (seeing the flock)

Question 15

principle of common region

Answer 15

elements within same region of space appear to be grouped together

Question 16

principle of uniform connectedness

Answer 16

connected region of similar visual properties (lightness, colour, texture, motion) perceived as one unit

Question 17

perceptual segregation

Answer 17

perceptual segregation of one object from another

Question 18

figure-ground segregation

Answer 18

• figures are more thinglike than background, more memorable
• figure is seen as in front of ground
• near borders shared with figure ground is seen as unformed material and seems to extend behind shape
• border seems to belong to figure

Question 19

image based factors of figure-ground segregation

Answer 19

• areas lower in field of view are more likely to be perceved as figure
• more likely to be perceived as figures when on convex side of border

Question 20

subjective factors of figure-ground segregation

Answer 20

• good continuation overrides effects of past experiences

- figure must be separated from ground before we assign meaning

Question 21

scene

Answer 21

view of real world environment with background elements and multiple objects arranged in a meaningful way relative to eachother and background

Question 22

gist

Answer 22

general description of a type of scene, very rapid

Question 23

persistence of vision

Answer 23

visual stimulation continues for 250 ms after stimulation ends

Question 24

visual masking system

Answer 24

blocks persistence of vision - random pattern shown that covers original image

Question 25

global image features

Answer 25

• degree of naturalness
• degree of openness
• degree of roughness
• degree of expansion (convergence of paralell lines)
• degree of colour

holistic and rapid

Question 26

physical regularities

Answer 26

regular occuring physical properties of the environment

• • vertical and horizontal lines
• objects often homogeneous in colour and contrasting to nearby objects
• light from above assumption

Question 27

semantic regularities

Answer 27

meaning of a function/scene, characteristics associated with functions carried out in different types of scenes

Question 28

Theory of unconscious inference

Answer 28

Helmhotlz; some of our perceptions are result of unconscious assumptions made about environment

Question 29

likelihood theory

Answer 29

we perceive object that is most likely to have caused pattern of stimuli we perceive (deals with ambiguity of perceptual stimulation)

Question 30

Bayesian inference

Answer 30

quantification of inference that includes probability

Question 31

binocular rivalry

Answer 31

one stimulation/image to each eye, can not perceive both at once