Horopter and Distance Perception (F) Flashcards Preview

III. Binocular Vision > Horopter and Distance Perception (F) > Flashcards

Flashcards in Horopter and Distance Perception (F) Deck (48):
1

What is the indication when AFPP is outside the VM circle at all distances?

temporal packing

2

What is the horopter a reference for? 1. What happens if it is abnormal? 2

1. reference surface for spatial relationships
2. spatial distortions in distance

3

What does the apparent curvature of OFPP cue?

absolute distance

4

Where is the stereothereshold the smallest?

near the horopter

5

What is SILO driven by?

1. process disparity
2. determine distance
3. apply size constancy

6

What are the different types of direction perceptions?

1. oculocentric
2. egocentric

7

What is the locus of points in physical space that have their images on corresponding retinal points (horizontal and vertical) called?

horopter

8

If you judge an object to be nearer to you, do you perceive the object to be smaller or larger?

smaller

9

What is the ability to perceive the correct size of an object despite changes in its retinal image size called?

size constancy

10

What is the relationship of the visual angle to physical size and physical distance? 1. Is this a perceptual or physical law? 2

1. Law of Visual Angle
2. physical

11

What law is an artist drawing more distant objects with a smaller angular subtense to represent greater distance an example of?

Law of visual angle

12

What is the concept of movement of body causes differential retinal image motion of objects at different distances?

motion parallax

13

What is considered to be the "true" horopter because of the fewest assumptions?

nonius criterion

14

Where is the line horopter relative to the Vieth-Muller circle for a patient with nasal packing?

line inside the VM circle

15

What is the pictorial representation that is relative depth is cued by the position of highlights and shadows on objects? 1. Why does this happen? 2

1. light and shadow
2. we interpret shadows as if light were coming from above

16

If you overestimate the distance of an object (station point), what happens to the distance between objects?

expanded depth

17

Does the amount of temporal packing increase or decrease at near? 1. Why? 2

1. increase
2. effect is neural in origin

18

Do we tend to over or under estimate station points? 1. What is the result? 2

1. underestimate
2. depth foreshortened

19

What are the different methods for measuring the horopter?

1. the apparent frontal parallel plan (AFPP) criterion
2. the Nonius criterion
3. the center of region of binocular single vision criterion
4. the stereoscopic sensitivity (made to be maximum sensitivity) criterion

20

What is the phenomenon of seeing more texture at near than distance, giving you an idea of what is closer called?

texture gradient

21

At what distance is the OFPP equal to the AFPP? 1. What is this called? 2

1. about 1m
2. abathic distance

22

If you underestimate the distance of an object (station point), what happens to the distance between objects?

foreshortened

23

What would happen if you perceived an object moving nearer to you, however the image size of the object on your retina remained constant?

percept would appear smaller because of size constancy

24

What is the pictorial representation that is the relative sizes of retinal images provide information about the relative distances of the objects?

linear perspective

25

When working with prism to increase convergence or divergence how do you perceive size and distance relationships?

opposite of SILO (SOLI)

26

What are the types of distance perception?

1. relative: distance between objects
2. absolute: distance from body (egocenter)

27

Does the OFPP appear more concave, convex, or the same with increasing distance?

concave

28

What is the pictorial representation to distance that has nearer objects occluding more distant ones called?

overlay

29

What is the plane parallel to the face plane that includes the fixation point called?

objective fronto-parallel plane

30

What are the components of spatial localization?

1. distance perception
2. direction perception

31

What is the pictorial representation that more distant objects are less distinct than closer due to atmospheric scatter?

aerial perspective

32

What does the Nonius horopter pass through as it deviates from the VM circle? 1. Where does it intersect? 2

1. through axis of the head
2. egocenter

33

What are the assumptions we make about object size when it comes to linear perspective?

1. similar looking objects are assumed to have identical sizes
2. continuous objects are assumed to be unchanging in size
3. familiar objects are assumed to be their expected size

34

How do the temporal beta angles for a patient with temporal packing compare to normal? 1. Nasal beta angles? 2

1. smaller
2. same

35

What is the method to measure the horopter in which the positions of points in physical space that appear to lie in an apparent fronto-parallel plane is analyzed?

AFPP criterion

36

What are the different types of constancies that the brain "assumes" about the world (and what each are irrespective of)?

1. shape constancy (irrespective of P.O.V.)
2. size constancy (irrespective of distance)
3. color constancy (irrespective of illuminant)
4. lightness constancy (irrespective of illuminant)

37

What is the method to measure the horopter in which the positions of points in physical space are such that the visual directions of the images formed in the two eyes are identical?

nonius criterion

38

What relationship is the basis for linear perspective?

between angular size and distance

39

What are the motion parallax rules?

1. image velocity is inversely proportional to object distance
2. image velocity is zero for the point toward which the body is moving (this is focus of expansion)
3. images of objects farther than the focus of expansion have with motion
4. images of objets nearer than the focus of expansion have against motion

40

What law is an observer perceiving the representation having a smaller angular subtense as more distant and larger an example of?

Emmert's Law

41

What are the limitations of distance perception?

1. stereoscopic relative distance perception is excellent only for short distances
2. absolute distance perception is not very accurate
3. size and distance perception interact
4. oculomotor cues to distance are not great

42

What is the idea that the distance of object is from an observer along the ground is inversely related to the angle subtended from the horizon?

relative height

43

What is a 2-dimensional surface showing the lateral position of corresponding points called? 1. What are the targets? 2

1. Line horopter
2. vertical lines

44

Where is the line horopter relative to the Vieth-Muller circle for a patient with temporal packing?

line outside VM circle

45

What is the rational behind the AFPP criterion to measure the horopter?

equidistant objects should form a flat surface (Hering)

46

Where is the line horopter relative to the Vieth-Muller circle for a patient with no retinal density difference?

matches the VM circle

47

What is the relationship of the perceived size and perceived distance? 1. Is this a perceptual or physical law? 2

1. Emmert's Law
2. perceptual

48

How do the temporal beta angles for a patient with nasal packing compare to normal? 1. Nasal beta angles? 2

1. same
2. smaller