Lecture 7

Question 1

What are illusory contours?

Answer 1

easily recognizable objects tend to be seen as complete, even if parts may be absent (particularly when borders/ edges, etc. are ‘implied’)

Question 2

What is the Principle of Good Continuation?

Answer 2

lines tend to be seen as following the
smoothest path possible

Question 3

What is the Principle of Pragnanz?

Answer 3

(principle of good
figure, or simplicity): every stimulus pattern is
seen in such a way that the resulting structure
is as simple as possible

Question 4

Describe the principle of similarity

Answer 4

similar things tend to be grouped together

Question 5

Describe principle of proximity

Answer 5

things that are close together in space tend to be
grouped together

Question 6

Describe law of common fate

Answer 6

objects moving in the
same direction tend to be grouped together

Question 7

Describe common region

Answer 7

elements in the same region tend to be grouped together
(e.g. ‘a’, above)

Question 8

Describe uniform connectedness

Answer 8

connected region of visual properties are perceived
as single unit (e.g. ‘b’, above)

Question 9

Describe figural cues

Answer 9

influence perceptual segregation
of figure from ground

Question 10

Describe Gibson and Peterson study

Answer 10

The black object in image ‘a’ is more likely to be
seen as the figure than in image ‘b’, presumably
based on the resemblance it carries to the outline
of a person (i.e. top-down processing)

• Both of these examples could be taken as
  instances in which experience ‘overrides’ Gestalt
  principles

Question 11

What is a scene?

Answer 11

Background elements

• Objects organized in meaningful ways with each other and the background

Question 12

Describe Potter study

Answer 12

demonstrated that people can extract the gist of a scene when a
picture is only presented for 250 ms (1/4 second)

Question 13

Describe Fei Fei study

Answer 13

scenes using masking (a random pattern that is
flashed onscreen immediately after a stimulus presentation, used to prevent
persistence of vision that can facilitate further processing after the image has
disappeared)

Question 14

What are the 5 traits of scenes?

Answer 14

1. Degree of naturalness: textured zones and undulating contours
   (natural) vs. straight lines (urban) (see next slide)
2. Degree of openness: number/density of objects, whether or not the
   horizon is visible (see next slide)
3. Degree of roughness/smoothness: number/size/complexity of
   elements
4. Degree of expansion: convergence of parallel lines (see next slide)
5. Colour: characteristic colours, e.g. blue for ocean, brown/green for
   forest

Question 15

Why are physical regularities important?

Answer 15

They influence how our perceptual
systems function

Question 16

Describe the light from above assumption

Answer 16

because light comes
from above in the natural (and many unnatural)
environments, this leads to particular expectations
about what information the location of shadows
convey about our physical environment

Question 17

Describe semantic regularities

Answer 17

the characteristics associated
with the functions carried out in different types of
scenes

Question 18

What is a scene schema?

Answer 18

the knowledge of what a
given scene ordinarily contains

Question 19

Describe Palmer’s study

Answer 19

very briefly presented a context
scene, followed by a target picture
* Targets congruent with the context were
identified 80% of the time
* Targets that were incongruent were only
identified 40% of the time