Chapter 6- Space Perception And Binocular Vision Flashcards Preview

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Flashcards in Chapter 6- Space Perception And Binocular Vision Deck (66):
1

Euclidean

Geometry of the real world

2

Why 2 eyes

So we can lose one but still see; see more of the world

3

Visual field is limited

190 degrees from left to right with 110 covered by both
140 degrees vertically with 60 above eyebrows and 80 down cheeks

4

Retinal images vary in __ dimensions (__ and __), but the world is in ___ dimensions

Two (x and y), three

5

Number of visual cues in the image provide information about the third dimension, which is ___

Depth

6

Eye cues are also available in the state of the ___ muscles

Oculomotor; physically moving eyes, muscle signals

7

____ cues involve combining the info from our two eyes together

Neural; only in higher level brain area

8

monocular cues

1 eye; depth cue that is available even when the world is viewed by just 1 eye

9

binocular cues

2 eyes; info from both eyes; setereopsis, convergence, seeing more info

10

relative size

object of a known size; comparison

11

relative height

further away, the higher up they appear on retina; objects at different distances from viewer on the ground plane will form images at different heights in the retinal image

12

texture gradient

building with windows, see fine detail vs things smooshed together

13

occlusion

something in front of something else; cue to depth order

14

arial perspective

due to the atmosphere, you lose contrast with distance (scattering); more light is scattered when we look through more atmosphere

15

linear perspective

as parallel lines get further away, they start to look closer; parallel in 3D, look like they converge in 2D, converge at vanishing point

16

visual cues (pictoral cues) include

relative size, relative height, texture gradient, occlusion, aerial perspective, motion parallax, shadows

17

eye cues (muscle cues) include

accommodation, vergence

18

neural cues (cortical) inclue

binocularity disparity

19

occlusion and shadows offer ___ info only

ordinal; just know that one thing is in front of the other

20

accomodation

the eyes lens must change shape to maintain sharply focused image as object distance varies; change shape to influence optic power

21

light rays from distant objects are nearly parallel and don't need as much ___ to bring them to focus

refraction

22

lights rays from close objects ____ and need more refraction for focusing

diverge

23

ciliary muscles ___, fibers slack, lens rounds to ___ strength for close vision

contract, greater

24

ciliary muscles ___ fibers taut, lens at ___ strength for distant vision

relaxed, minimum

25

less refraction for stuff ____, more refraction for stuff ___

far way, up close

26

vergence

the extraocular muscles turn the eyes in toward each other to maintain binocular fixation, to an extent that depends on fixation distance; vergence angle is how much eye is turned (strabismum)

27

divergence

fixating a distant object, vergence angle is small, eyes turn outward

28

convergence

while fixating a near object, vergence angle is large, eyes turn inward

29

binocular disparity

the differences between the two retinal images of the same scene

30

disparity

basis for stereopsis, vivid perception of the three-dimensionality of the world that is not available with monocular vision

31

eyes are set apart, so they get ____ images

slightly different

32

when looking at something, eyes straight ahead, spot fall on ___ of ___

both, foveas

33

if we aren't directly looking at something, it falls ___

on different spots

34

the farther away the thing we are looking at is

the more inside it is on the fovea

35

the closer something is that we are looking at

outside fovea

36

crossed

right eye to left visual field, left eye to right visual field ; near disparity; in front of plane of fixation

37

uncrossed

eye and visual field are the same; far disparity; behind plane of fixation

38

zero disparity

equidistant from point of fixation, horopter line

39

stereopsis

ability to use binocular disparity as cue to depth

40

corresponding retinal points

geometric concept stating that points on the retina of each eye where the monocular retinal images of a single object are formed at the same distance from the fovea in each eye

41

horopter

the location of objects whose images lie on the corresponding points; surface of zero disparity

42

random dot stereorgrams show that ___ alone is sufficient to support and impression of depth

disparity

43

how are random dot stereogram's constructed

one image is deliveredto each eye, two images contain identical arrays of dots, except that a subset of dots in one image is shifted in position relative to their position in the other image

44

an object is possible if ____ between two eyes made

correct match

45

objects on the ___ are seen as single imaged when viewed with both eyes

horopter

46

panum's fusional area

the region of space, in front of and behind the horopter, within which binocular single vision is possible; wider range around the horopter

47

objects closer or farther away from the horopter fall on ___ points in the two eyes and are seen as two objects

noncorresponding

48

diplopia

double vision. if visible in both eyes, stimuli falling outside of panum's fusional area will appear diplopic

49

binocular rivalry

the competition between the two eyes for control of visual perception, which is evident when completely different stimuli are presented to the two eyes

50

the competition of binocular rivalry is ____ an d___

equal and balanced

51

interocular suppression

image from one eye perceived, image from the other eye is not perceived; people with strabismus

52

input from two eyes must __ onto the same cell

converge

53

binocular neurons respond best when the retinal images are on __ points in the two retinas: neural basis for the ___

corresponding; horopter

54

___ neurons are tuned ot particular binocular disparity

binocular

55

texture gradient

relative distance of the object, squash faster along vertical rather than horizontal

56

motion parallax

images closer to the observer move faster across the visual field than images farther away; based on head movement, objects closer shift position more

57

cast shadows

1 object onto another, relative distance between object and light source

58

attached shadows

within same object, local depth parts of object put shadows on other parts of the object

59

shadows assume

convex objects, light is from above

60

combining info from different cues can derive robust, reliable depth estimates when given the ___ between cues

correlation

61

___ vary in availability and reliability

individual cues

62

assumed that human depth estimates are based on ___ average of cue values, with weights varying according to viewing conditions

weighted

63

hollow face illusion

concave mask perceived as convex when monocular cues dominate because of assumptions about objects and shadows

64

strabismus

misalignment in the eyes; brain suppresses 1 image of the 2 on each fovea to avoid diplopia

65

amblypia

weak vision in one eye

66

strabismus and amblypia are main reason to not have __ __ __

stereoscopic depth perception, environmental causes