depth and size pt 2

Question 1

binocular

Answer 1

cues that depend on input from both eyes

- stereoscopic depth perception

Question 2

binocular cues

Answer 2

binocular disparity

- difference in images on left and right retinas

Question 3

corresponding/noncorresponding retinal points

Answer 3

corresponding: objects ON the horopter
- fall at the same distance from fovea on both eyes
noncorresponding: objects OFF the horoptor
- furthur from fovea in one eye than the other

Question 4

horopter

Answer 4

all things on equal distance of what were currently looking at

Question 5

angle of disparity

Answer 5

crossed- second object is closer
-right side in left eye/ left side of right eye
uncrossed- second object is furthur
-left side in left eye/right side in right eye

Question 6

absolute disparity

Answer 6

angle from corresponding points
- how far away things are from the horopter
(does change with gaze)
ex. daves absolute disparity is greater than bills so therefor dave is furthur from the horopher than bill
HIGHER ABSOLUTE DISPARITY = FARTHER FROM HOROPTER

Question 7

relative disparity

Answer 7

difference in disparities between objects
(doesnt change with gaze)
- how for away things are from eachother

Question 8

stereopsosis

Answer 8

perception of depth due to binocular disparity

ex. random dot stereogram: some differences in picture makes brain think there is depth in the image

Question 9

what is the correspondance problem

Answer 9

how does the brain match up different points in two retinal images
- brain is constantly comparing images in 2 eyes and has to find what matches up with the real world with litttle information

Question 10

how does brain solve correspondance problem

Answer 10

using features of objects to distinguish them

ex. color or shape

Question 11

summary how do we perceive depth

Answer 11

oculomotor- convergance & accomodation
monocular- pictorial cues & motion cues
binocular cues- binocular disparity (biggest source of phenomonology)

Question 12

relationship b/w depth and size

Answer 12

• very closely related, to determine size you need depth and depth you need to know size
  a small near object and large distant one has same identical visual angles and retinal images

Question 13

what is the boring experiment

Answer 13

viewers had to judge whether objects were the same or different sizes when presented at different distances
(4 conditions)- 1. full depth cues, 2. one eye, 3. no motion and 4.no shadows
result: discovered as you lose depth cues you lose the ability to judge size (have to rely on image in retina)

Question 14

size constancy

Answer 14

same size objects at different depths form different size images on retina (and different visual angles)
but we still can perceive them as the same size
S= K(RxD) where k is a constant

Question 15

what is the ponzo illusion

Answer 15

objects that are the same actual size are perceived to be different due to different perceived depth cues

Question 16

ames room

Answer 16

misperception of size due to the misperception of distane

assumes parallel walls so assume people change sizes but room is slanted

Question 17

cells responsible for depth/size perception

Answer 17

starts in V1

cells fire the most when stimulation is at slightly different fields

Question 18

dorsal/ventral streams in depth perception

Answer 18

dorsal - absolute disparity (guiding action)

ventral- relative disparity (identifying objects)

Question 19

how are sterescopic movies created

Answer 19

• record slightly different points of view for 2 eyes to create perception of depth
• colored lenses filter so you only see 1 image at a time
• polarized lens deliver 1 image at a time
• LCD lenses open and close each lens in term
• head mounted displays

Question 20

interference filter technology

Answer 20

slightly shifted bands of red green and blue wavelengths

-wavelength multiplex visualization

Question 21

parallax barrier autosterescopy

Answer 21

uses tiny barriers to allow one image to reach each eye

ex. nintendo 3DS