Lecture 14

Question 1

Cue approach to depth perception

Answer 1

focuses on information in the retinal image that is correlated with depth in the scene

Question 2

Oculomotor cues

Answer 2

based on sensing the position of the eyes and muscle tension

Question 3

Convergence

Answer 3

inward movement of the eyes when we focus on nearby objects

Question 4

Accommodation

Answer 4

the shape of the lens changes when we focus on objects at different distances

Question 5

monocular cues

Answer 5

information that can be based on the image from a single eye

Question 6

pictorial cues

Answer 6

sources of depth information that come from 2-D images, such as pictures

Question 7

occlusion

Answer 7

when one object partially cover another

Question 8

perspective convergence

Answer 8

parallel lines appear to come together in the distance

Question 9

relative size

Answer 9

when objects are equal size, the closer one will take up more of your visual field

Question 10

Atmospheric perspective

Answer 10

distance objects appear more ‘fuzzy’

Question 11

Why does atmospheric perspective occur

Answer 11

because the farther away something is, the more air/particles we have to look through to see it

Question 12

farther objects also tend to appear more ‘___’ because our atmosphere preferentially scatters short wavelengths and looking ‘through’ more of it increases the ‘___’

Answer 12

farther objects also tend to appear more ‘blue’ because our atmosphere preferentially scatters short wavelengths and looking ‘through’ more of it increases the ‘blueness’

Question 13

texture gradient

Answer 13

equally spaced elements are more closely packed as distance increases, things farther away from you look more densely packed than things closer to you

Question 14

shadows

Answer 14

helps enhance depth by indicating where object/feature are located

Question 15

motion parallax

Answer 15

close objects in direction of movement glide rapidly past but objects in the distance appear to move slowly, relates to the larger distance the image of something closer to us ‘travels’ across the retina

Question 16

objects are covered (__) or uncovered (__) as we move relative to them

Answer 16

objects are covered (deletion) or uncovered (accretion) as we move relative to them

Question 17

Stereoscopic depth perception

Answer 17

constructed based on input provided to both eyes, basis for how 3D glasses typically work (presenting different images to each eye that get combined)

Question 18

Corresponding retinal points

Answer 18

points on the retina that would overlap if the eye were superimposed on each other

Question 19

Binocular disparity

Answer 19

difference in images from two eyes

Question 20

horopter

Answer 20

imaginary sphere that passes through the point of focus

Question 21

Objects that are not on the horopter fall on __-__ points, these points make __ images

Answer 21

Objects that are not on the horopter fall on non-corresponding points, these points make disparate images

Question 22

absolute disparity

Answer 22

degree to which disparate images deviate from corresponding points

Question 23

Crossed disparity

Answer 23

occurs whenever an object is closer to the observer than where they are looking (in front of the horopter)

Question 24

Uncrossed disparity

Answer 24

occurs whenever an object is farther away from the observer than where they are looking (behind the horopter)

Question 25

Stereopsis

Answer 25

depth information provided by binocular disparity

Question 26

stereoscopes

Answer 26

viewers which use two different pictures from slightly different viewpoints

Question 27

random-dot stereograms

Answer 27

two identical patterns of ‘noise’ with one ‘piece of information’ shifted in position, allow researchers to isolate contributions to depth perception attributable to stereopsis

Question 28

correspondence problem

Answer 28

question of how we ‘line up’ what is happening in one retina with what is happening in the other

Question 29

A possible solution to the correspondence problem

Answer 29

encoding not only where points on the retina are being stimulated but also some associated feature e.g. colour

Question 30

Binocular depth cells/ disparity selective cells

Answer 30

neurons that respond best to binocular disparity

Question 31

Binocular depth cells/ disparity selective cells are found in __ as well as along the __ and ___ __

Answer 31

Binocular depth cells/ disparity selective cells are found in V1 as well as along the dorsal and ventral streams

Question 32

Binocular depth cells/disparity selective cells respond best to a ___ ___ of ___ ___ between images on right and left retinas

Answer 32

Binocular depth cells/disparity selective cells respond best to a specific degree of absolute disparity between images on right and left retinas

Question 33

Disparity tuning curves

Answer 33

plot neural response as a function of disparity

Question 34

Elimination of disparity-selective neurons by ___ ___ eliminates ___ ___ perception

Answer 34

Elimination of disparity-selective neurons by selective rearing eliminates binocular depth perception

Question 35

___ of disparity-selective neurons changes depth perception

Answer 35

microsimulation of disparity-selective neurons changes depth perception

Question 36

binocular disparity causes firing of __-___ cells

Answer 36

binocular disparity causes firing of disparity-selective cells

Question 37

binocular disparity causes perception of ___ (___)

Answer 37

binocular disparity causes perception of depth (stereopsis)