Problem Set #2-Facts

Question 1

Gestalt Grouping Principle: Proximity Example

Answer 1

Dots that are near each other group together

Question 2

Gestalt Grouping Principle: Similarity Example

Answer 2

Dots that have the same colour group together

Question 3

Gestalt Grouping Principle: Good continuation

Answer 3

Short edges that are approximately lined up group together
into a longer perceived contour

Question 4

Gestalt Grouping Principle: Parallelism

Answer 4

parallel lines, even if they are curved, tend to group together

Question 5

Gestalt Grouping Principle: Symmetry

Answer 5

Symmetrically arranged dots or lines group together into a single perceived object

Question 6

Gestalt Grouping Principle: Common Region Example

Answer 6

Drawing an ellipse around pairs of dots causes them
to group together

Question 7

Gestalt Grouping Principle: Connectedness Example

Answer 7

Drawing a line that connects pairs of elements causes them to
group together

Question 8

Accidental Viewpoint

Answer 8

A viewpoint that produces a regularity in the image (e.g., a connected line, a straight
edge) that is not present in the world

Question 9

What is the Gestalt principle of “common region”?

Answer 9

Features tend to group together if they appear to be part of the same region

Question 10

What is prosopagnosia?

Answer 10

The selective inability to perceive faces

Question 11

What is a nonaccidental feature?

Answer 11

a) a feature of an object that does not depend on the exact viewing position of the
observer, or (b) a feature that, if present in a 2D image, is very likely to be present in
the 3D scene depicted as well (e.g., parallel edges

Question 12

What is an illusory contour?

Answer 12

A contour that we perceive where there is actually no contour in the image

Question 13

What is the global superiority effect?

Answer 13

The finding that properties of a whole object often perceptually override properties of
parts of the object

Question 14

What are “relatable” edges?

Answer 14

Edges that can be joined by a simple, smooth curve

Question 15

What is unique blue?

Answer 15

A hue that people see as containing blue but no red or green

Question 16

What is colour constancy?

Answer 16

The ability to perceive surface colour correctly despite changes in the colour of the
illumination

Question 17

What is a spectral power distribution?

Answer 17

A plot showing the amount of power that a light source has at each wavelength

Question 18

Name three absolute metrical depth cue.

Answer 18

vergence, accommodation, familiar size

Question 19

What is the Vieth-Müller circle?

Answer 19

An imaginary circle through the two eyes and the fixation point

Question 20

What is the horopter?

Answer 20

The set of all points in space that create retinal images with zero disparity
(i.e., that cast retinal images an corresponding points)

Question 21

What is Panum’s fusional area?

Answer 21

Region in space where our brain can merge slightly different images from our left and right eyes into a single, three-dimensional image.

Question 22

Name the first area in the visual pathway that contains binocular neurons.

Answer 22

primary visual cortex ( = striate cortex, V1 )

Question 23

Name 5 pictorial depth cues

Answer 23

1) Texture gradient
2) Occlusion
3) Relative Height
4) Relative Size
5) Familiar size

Question 24

Texture Gradient - Pictorial Cue

Answer 24

The size of texture elements is smaller at larger distances

Question 25

Occlusion- pictorial cue

Answer 25

Nearer objects occlude farther objects.

Question 26

Relative height - pictorial cue

Answer 26

More distant objects tend to be higher in the visual field.

Question 27

Relative Size -pictorial cue

Answer 27

More distant objects tend to have smaller retinal images.

Question 28

Familiar Size- pictorial cue

Answer 28

If we know the true size of an object, we can use the size of its retinal image to infer its distance

Question 29

What is diplopia?

Answer 29

Double vision, such as occurs when disparities are too great to be fused

Question 30

If we show this figure in a stereoscope, with the right eye viewing (a) and the left
eye viewing (b), does he inner circle appear to be in front of or behind the outer circle?

Answer 30

The inner circle in the figure has more disparity than the outer circle when viewed through the stereoscope, it will appear to be in front of the outer circle