feb 6

Question 1

binocular neurons first found in

Answer 1

V1, then V2, V3, V4, V5

Question 2

neurons needed for stereopsis and fusion must be __

Answer 2

binocular

Question 3

model for how binocular neurons work

Answer 3

red neuron responds to crossed disparity; blue to uncrossed disparity; neither respond to 0 disparity

Question 4

disparity-tuned neurons

Answer 4

respond when stimulus is presented simultaneously to non-corresponding points; each responds to narrow range of disparities; tuned excitatory/inhibitory neurons; depth magnitude

Question 5

reciprocal neurons

Answer 5

near cells: show excitation to crossed disparity and inhibition to uncrossed disparity; far cells are opposite; depth order

Question 6

near cells are ____ neurons that show ____ to crossed disparity and ____ to uncrossed disparity

Answer 6

reciprocal; excitation; inhibition

Question 7

far cells are ____ neurons that show ____ to crossed disparity and ____ to uncrossed disparity

Answer 7

reciprocal; inhibition; excitation

Question 8

binocular neurons (2) (and found where)

Answer 8

disparity-tuned neurons & reciprocal neurons found in V1 and V2

Question 9

dorsal stream areas include _____, which process depth ___

Answer 9

V3a, hMT+, V7; magnitude

Question 10

ventral stream areas including __ process depth __

Answer 10

LOC; order

Question 11

absolute disparity (what, found where)

Answer 11

difference in distance of the image of an object from the fovea in each eye; mainly dorsal stream [hMT+/IPS]; may control vergence eye movements

Question 12

relative disparity

Answer 12

difference in absolute disparities of 2 objects; mainly ventral stream; 3D shape perception and stereoacuity

Question 13

visual cliff used to study

Answer 13

binocular vision in babies

Question 14

visual cliff tells us that depth perception is present in human infants by __ months of age

Answer 14

6

Question 15

babies don’t have ____ cuz their eyes don’t move together; eyes move together by ___ months

Answer 15

fusion; 3-4

Question 16

to study stereopsis in human infants, babies wear ____ with ___ display on one side, and __ display on the other; _______ technique is used; stereopsis appears between _ and _ months

Answer 16

stereoglasses; flat; 3D; preferential looking; 3-5

Question 17

stereoacuity

Answer 17

smallest amount of binocular disparity that can be detected; improves rapidly with age

Question 18

maturation of stereoacuity

Answer 18

close to adult levels by 6 months; not fully mature until after 14

Question 19

visual evoked potentials (VEPs)

Answer 19

electrical signals measured from scalp in response to visual stimulation

Question 20

when do babies show adult brainwave pattern for random-dot stereogram using VEPs?

Answer 20

2-7 months

Question 21

hypotheses for why stereopsis sudden

Answer 21

-vergence eye mvts becomes accurate (no)
-disparity-sensitive neurons in V1 mature (no)
-ocular dominance columns appear (no)
-disparity sensitivity in V2 matures (not sure)
-other aspects of V1 disparity-sensitive neurons mature (not sure)

Question 22

T/F: vergence eye movements are essential for development of stereopsis

Answer 22

false

Question 23

horopter vs panum’s area

Answer 23

horopter is imaginary line through fixation point; panum’s area is around horopter

Question 24

monocular deprivation (what, caused by what)

Answer 24

brain does not receive stimulation from one eye; caused by a cataract in human infants

Question 25

monocular deprivation results in ___

Answer 25

permanent poor visual acuity in deprived eye (amblyopia) and no stereopsis; shift in ocular dominance columns

Question 26

what happens to ocular dominance columns when monocular deprivation occurs?

Answer 26

instead of alternating white and black stripes, most of V1 is driven by the functioning eye (e.g. more white, thin black stripes)

Question 27

strabismus

Answer 27

less severe form of visual deprivation; misalignment of eyes (one eye fixates, the other esotropia/exotropia)

Question 28

results of strabismus

Answer 28

2 eyes looking in different directions; fixated objects stimulate non-corresponding points in the 2 eyes

Question 29

T/F: if develop strabismus as an adult, diplopia (double vision) occurs, but not when develop as a child

Answer 29

true

Question 30

suppression scotoma

Answer 30

brain ignores parts of the retina where the diplopic image would fall

Question 31

strabismus with interocular suppression

Answer 31

part of image from one eye ignored; often both eyes maintain good visual acuity; usually no stereopsis, relatively normal ocular dominance columns; few binocular neurons

Question 32

similarities between effects of monocular deprivation vs strabismus (ocular dominance columns, monocular & binocular cortical neurons, visual acuity, stereopsis)

Question 33

differences between effects of monocular deprivation vs strabismus (ocular dominance columns, monocular & binocular cortical neurons, visual acuity, stereopsis)

Question 34

______ is an adaptive mechanism in people with strabismus to prevent double vision (diplopia)

Answer 34

interocular suppression

Question 35

___ _____ image tends to be suppressed, but ___ exclusively

Answer 35

less salient; never

Question 36

binocular rivalry

Answer 36

competition between two eyes for control of visual perception

Question 37

rivalry and suppression occur for everything outside of ____

Answer 37

Panum's Area

Question 38

example of normal interocular suppression

Answer 38

suppressing nose

Question 39

depth reversal illusion example

Answer 39

avocado pit or no pit