Topic 8- Perceiving depth and size

Question 1

Will describe the many ways we use…

…determine the depth and size of things in our environment.

Answer 1

different sources of visual and environmental information to help us

Question 2

How do we perceive distances in the 3D environment?

Answer 2

Our ability to perceive these distances in the 3D environment is based entirely on the image (2D) that is hitting the retina.

Question 3

What are the 3 major cues that signal depth?

Answer 3

1. Oculomotor cues
2. Monocular cues
3. Binocular cues

Question 4

What are oculomotor cues?

4pts

Answer 4

• Cues that rely on our ability to sense the position of our eyes and the feeling of tension in our eyes muscles

Created by:
1. Accommodation: Change in the shape of the lens that occurs when we focus on objects at various distances

2. Convergence: Inward eye movements that occurs when we look at nearby objects

Together, these indicate when an object is close.

Question 5

What are Monocular cues?

3pts

Answer 5

• Cues for depth perception that can work when we use only 1 eye
• Does include accommodation but mainly pictorial and movement-based cues
• Pictorial cues: Sources of depth information that could be gathered from a picture, without the need for movement

Question 6

Pictorial monocular cues- What is the depth cue occlusion?

Answer 6

Depth cue in which one object hides or partially hides another object from view, causing the hidden object to be perceived as farther away.

Question 7

Pictorial monocular cues- What is relative height?

Answer 7

Objects that are higher in the visual field are (usually) further away than objects lower in the visual field.

Question 8

Pictorial monocular cue- What is familiar size?

Answer 8

Judgement of a distance based on previous knowledge of the size of objects.

Question 9

Pictorial monocular cue- What is relative size?

Answer 9

When two objects are of equal size, the one that is farther away will take up less of your field of view.

Question 10

Pictorial monocular cue- What is perspective convergence?

Answer 10

Perception that parallel lines converge as depth increases

Question 11

Pictorial monocular cue- What is texture gradients?

Answer 11

Objects appear more textured when closer to us and less textured as distance increases

Question 12

What pictorial monocular cue is this?

• Help us better determine the location and placement of objects relative to others
• Help with defining shape

Answer 12

Shadows

Question 13

Movement Monocular cue- Motion parallax

Answer 13

As we move, nearby objects appear to be moving faster across our visual field, whereas farther objects appear to be move more slowly

Question 14

Movement Monocular cue- Deletion and accretion

Answer 14

Moving sideways, some things become covered, and some things become uncovered (when it re-emerges)

Question 15

What are binocular cues?

2pts

Answer 15

• Stereoscopic vision/stereopsis
• “Two-eyed depth perception” that considers differences in the images hitting the left and right retinal surfaces

Question 16

What is binocular disparity?

Answer 16

Occurs when the 2 retinal images are slightly different angles, then the brain compares these 2 images and uses the difference/disparity to figure out the distance of the object

Question 17

In binocular disparity what are the corresponding retinal points and the non-corresponding retinal points ?
2pts

Answer 17

Corresponding retinal points: points on the retina that would overlap if the eyes were superimposed on top of each other

Non-corresponding retinal points: points on the retina that would not overlap if superimposed

Question 18

Objects that fall on corresponding points are located on the BLANK

If the angle is large= object is…

If the angle is small= object is…

Answer 18

horopter

• object is closer than the horopter/to us
• object is farther than the horopter/to us