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Flashcards in Problem 6 Deck (34)
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1

Occlusion
(Pictorial cue)

Occurs when one object partially hides another from view

--> partially hidden object is perceived to be more distant

2

Oculomotor cues

Created by

1. CONVERGENCE
--> inward movement of the eyes that occurs when we look at nearby objects

2. ACCOMMODATION
--> the change in the shape of the lens, when focusing on objects

=> cues based on our ability to sense the position of our eyes

3

Monocular cues

Cues that work with one eye

a) accommodation
b) pictorial cues
c) motion produced cues

4

Pictorial cues

Sources of depth information that can be depicted in a two dimensional picture

--> cues are stationary/fixed

5

Relative size
(Pictorial cue)

When 2 objects are of equal size, the one farther away will take up less of our view than the one closer

--> cue depends on a persons knowledge of physical sizes

6

Familiar size
(Pictorial cue)

Cues used when judging the distance based on prior knowledge of the size of objects

7

Texture gradient
(Pictorial cue)

Elements equally spaced in a scene appear to be more closely packed as distance increases

8

Relative height
(Pictorial cue)

Objects with their bases closer to the horizon are usually seen as being more distant

9

Perspective convergence
(Pictorial cue)

Cue experienced when looking down parallel lines that appear to converge in distance

10

Atmospheric perspective
(Pictorial cue)

Occurs when distant objects appear less sharp than nearer objects, with a slight blue tint

--> works above 30 m

11

Shadows
(Pictorial cue)

Decreases in light intensity caused by a blockage of light that provide info about the location of objects

12

Motion produced cues

Cues that emerge when we start moving, that enhance our perception of depth

--> works at close + medium ranges

13

Motion parallax
(Motion-produced cue)

Occurs when nearby objects appear to glide rapidly past us, but more distant objects appear to move more slowly

ex.: moving nearby cars seem to speed away in a blur, whereas those farther away seem to be moving slowly

14

Deletion + Accretion

As one moves sideways, some things become covered (=deletion) and some become uncovered (= accretion)

15

Stereoscopic vision

Ability to use disparity between 2 eyes as a cue to depth

16

Binocular disparity

Describes the differences between two retinal images of the same scene

--> basis for stereopsis

17

Corresponding retinal points

Points on the retina that overlap if the eyes are superimposed on each other

18

Horopter

Imaginary circle that passes through the point of focus

--> the surface has 0 disparity

19

Non-corresponding points

Images of objects that are not on the horopter fall on non-corresponding points

20

Absolute disparity

The degree to which these objects deviate from falling on corresponding points

--> determined by measuring the angle between where the CP would be located and where it is actually located

21

Angle of disparity

Amount of absolute disparity

--> provides info about the objects distance from the horopter

22

Crossed disparity

Sign of disparity produced by objects in front of the horopter

1. You would need to "cross" your eyes to fixate on the object in front of you

2. Objects appear to be displaced to the right in the left eye and vice versa

23

Uncrossed disparity

Sign of disparity produced by objects behind the horopter

--> objects seem to be displaced to the right in right eye + same for left eye

24

Relative disparity

The difference in absolute disparities of objects in a scene remains the same as an observer looks around the scene

--> helps indicate where objects are located relative to others

25

Random dot stereogram

Stereogram made of a large number of randomly placed dots, that contains no monocular cues to depth

--> shows that disparity alone can result in depth perception

26

Correspondence problem

Refers to the question of how the visual system matches the parts of the images in the left and right eyes that correspond to one another?

27

Binocular depth cells
(Disparity selective cells)

Respond best when stimuli presented to either eye create a specific degree of absolute disparity

28

Which cortical areas are involved in depth perception ?

Depth perception starts in primary visual area and extends into different areas in the ventral + dorsal streams

29

Selective rearing

If an animal is reared in an environment that contains only certain types of stimuli, neurons that respond to these stimuli will become more prevalent

--> explains why we respond predominantly to vertical + horizontal lines

30

Size constancy

Refers to the fact that our perception of an objects size is relatively constant, even when we view the object from different distances