L5 - Binocular vision and depth perception

Question 1

What is Depth Perception?

Answer 1

Judgement of the location of objects in depth

Question 2

What is a monocular cue?

Answer 2

What you can perceive with just one eye in regards to depth.

Question 3

Name 3 monocular cues.

Answer 3

Texture gradient (shading)

Size

Occlusion

Question 4

What is a binocular cue?

Answer 4

What you need two eyes to perceive in regards to depth.

Question 5

Name the two binocular cues.

Answer 5

Vergence

Stereo (Disparity Information)

Question 6

Is texture gradient and shading a monocular or binocular cue?

How does texture gradient and shading influence depth perception?

Answer 6

Monocular Cue

You can use shading to make inferences about depth.

Shadows anchored to the form give an idea of volume (bottom picture)

Question 7

With shading and perception, things that are darker are seen as (a) ___ and things that are lighter are seen as (b)___.

Fill in the blanks

Answer 7

(a) Further Away
(b) Closer

Question 8

Is size constancy a monocular or binocular cue?

How does size constancy help with our depth perception?

Answer 8

Monocular Cue

Because we have a general understanding of how big things should be, we are able to judge how far away they are based on how big they are.

Question 9

Is occlusion a monocular or binocular cue?

What is occlusion? How does it help with depth?

Answer 9

Monocular Cue

Occlusion is when parts of a scene are in front of other parts of a scene.

Train is in front of station, which is in front of bus, therefore train is closer than the bus.

Question 10

What is binocular disparity?

Answer 10

The difference (distance) between your left and right eye.

Question 11

What are the three types of binocular disparity?

Answer 11

Far Disparity

Vertical Disparity

Near disparity

Question 12

What is the horopter?

Answer 12

It is the fixation plane, the line where you no longer get a disparity if you are looking through either eye.

dictionary: a line or surface containing all those points in space whose images fall on corresponding points of the retinas of the two eyes.​

Question 13

With depth perception, which kind of disparity will be seen as ‘crossed’ and which type will be seen as ‘uncrossed’ when looking through one eye?

Answer 13

Near Disparity = Crossed

Far Disparity = Uncrossed

Question 14

Where is the nonfixated point if you have far (uncrossed) disparity? Where is the right eye’s view relative to the lefts?

Where is the nonfixated point if you have near (crossed) disparity?

Answer 14

Far disparity = Further away

Right eye’s view of the point is shifted right, relative to left eye’s view.

Near disparity = Nearer away (closer)

Right eye’s view of the point is shifted left relative to the left eye’s view

All relative to the fixation plane (horopter)

Question 15

What is peripersonal space?

Answer 15

The area around you (between 50-150cm around you). It is where your binocular disparity is most sensitive.

It is the space you can interact with (where your about to walk)

Question 16

What is the random dot stereogram experiment?

What were the results?

Answer 16

Stereo viewing technique used to show the left eye image to the left eye and the right eye image to the right eye.

Results: horizontal disparity introduced by shifting the position of one eye’s view relative to the other eye view.

Question 17

What was the theoretical significance of the results from the random dot stereogram?

Answer 17

The disparity was presented in the absence of all other depth cues.

It shows that disparity alone is sufficient for people to see depth.

Question 18

What is the correspondence problem?

Answer 18

The problem of how the brain matches up the images from the left eye and right eye.

Question 19

Which experiment would be a good paradigm to test the correspondence problem? Why?

Answer 19

The Random Dot Stereogram

Because it is a ‘pure stimulus’ (just simulated dots, no complex form information like animals etc.)

Shows that disparity alone is enough to see depth

Question 20

What would be the advantage of having eyes that are wider apart?

Answer 20

You would have a larger field of view but less binocular vision.

Birds are like this.

Question 21

What is binocular vision good for?

Answer 21

Precise information about depth.

Catching balls, picking berries etc.