Chapter 6- Space Perception And Binocular Vision

Question 1

Euclidean

Answer 1

Geometry of the real world

Question 2

Why 2 eyes

Answer 2

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

Question 3

Visual field is limited

Answer 3

190 degrees from left to right with 110 covered by both

140 degrees vertically with 60 above eyebrows and 80 down cheeks

Question 4

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

Answer 4

Two (x and y), three

Question 5

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

Answer 5

Depth

Question 6

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

Answer 6

Oculomotor; physically moving eyes, muscle signals

Question 7

____ cues involve combining the info from our two eyes together

Answer 7

Neural; only in higher level brain area

Question 8

monocular cues

Answer 8

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

Question 9

binocular cues

Answer 9

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

Question 10

relative size

Answer 10

object of a known size; comparison

Question 11

relative height

Answer 11

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

Question 12

texture gradient

Answer 12

building with windows, see fine detail vs things smooshed together

Question 13

occlusion

Answer 13

something in front of something else; cue to depth order

Question 14

arial perspective

Answer 14

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

Question 15

linear perspective

Answer 15

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

Question 16

visual cues (pictoral cues) include

Answer 16

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

Question 17

eye cues (muscle cues) include

Answer 17

accommodation, vergence

Question 18

neural cues (cortical) inclue

Answer 18

binocularity disparity

Question 19

occlusion and shadows offer ___ info only

Answer 19

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

Question 20

accomodation

Answer 20

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

Question 21

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

Answer 21

refraction

Question 22

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

Answer 22

diverge

Question 23

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

Answer 23

contract, greater

Question 24

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

Answer 24

relaxed, minimum

Question 25

less refraction for stuff ____, more refraction for stuff ___

Answer 25

far way, up close

Question 26

vergence

Answer 26

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)

Question 27

divergence

Answer 27

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

Question 28

convergence

Answer 28

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

Question 29

binocular disparity

Answer 29

the differences between the two retinal images of the same scene

Question 30

disparity

Answer 30

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

Question 31

eyes are set apart, so they get ____ images

Answer 31

slightly different

Question 32

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

Answer 32

both, foveas

Question 33

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

Answer 33

on different spots

Question 34

the farther away the thing we are looking at is

Answer 34

the more inside it is on the fovea

Question 35

the closer something is that we are looking at

Answer 35

outside fovea

Question 36

crossed

Answer 36

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

Question 37

uncrossed

Answer 37

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

Question 38

zero disparity

Answer 38

equidistant from point of fixation, horopter line

Question 39

stereopsis

Answer 39

ability to use binocular disparity as cue to depth

Question 40

corresponding retinal points

Answer 40

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

Question 41

horopter

Answer 41

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

Question 42

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

Answer 42

disparity

Question 43

how are random dot stereogram’s constructed

Answer 43

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

Question 44

an object is possible if ____ between two eyes made

Answer 44

correct match

Question 45

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

Answer 45

horopter

Question 46

panum’s fusional area

Answer 46

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

Question 47

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

Answer 47

noncorresponding

Question 48

diplopia

Answer 48

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

Question 49

binocular rivalry

Answer 49

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

Question 50

the competition of binocular rivalry is ____ an d___

Answer 50

equal and balanced

Question 51

interocular suppression

Answer 51

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

Question 52

input from two eyes must __ onto the same cell

Answer 52

converge

Question 53

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

Answer 53

corresponding; horopter

Question 54

___ neurons are tuned ot particular binocular disparity

Answer 54

binocular

Question 55

texture gradient

Answer 55

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

Question 56

motion parallax

Answer 56

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

Question 57

cast shadows

Answer 57

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

Question 58

attached shadows

Answer 58

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

Question 59

shadows assume

Answer 59

convex objects, light is from above

Question 60

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

Answer 60

correlation

Question 61

___ vary in availability and reliability

Answer 61

individual cues

Question 62

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

Answer 62

weighted

Question 63

hollow face illusion

Answer 63

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

Question 64

strabismus

Answer 64

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

Question 65

amblypia

Answer 65

weak vision in one eye

Question 66

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

Answer 66

stereoscopic depth perception, environmental causes