L12 - Spatial Vision

Question 1

What is spatial vision??

Answer 1

Refers to the ability to perceive and interpret spatial relationships in our environment, including the location, size, and orientation of objects

Question 2

What is spatial frequency?

Answer 2

The level of detail present in a visual stimulus, measured in cycles per degree of visual angle
- Low spatial frequency for broad shapes (e.g., landscape)

Question 3

What is contrast sensitivity?

Answer 3

The ability to detect differences in luminance between areas of lightness and darkness
- Is essential for us to be able to detect objects, in particular edges

Question 4

What is one way to measure contrast sensitivity?

Answer 4

Present patches with different levels of contrast and see how much you can reduce the contrast before the lines disappear
- Diff people will have diff thresholds for same patch
- Threshold is high if you can just see the lines at a high contrast level - means low sensitivity

Question 5

What was found about the CSF of different animals?

Answer 5

While cats are more sensitive to lower spatial frequency (useful for the detection of motion), some raptors are sensitive to higher spatial frequencies

Question 6

What is the oblique effect (Campbell et al (1966))??

Answer 6

We are differently sensitive to diff orientations
- Are most sensitive to horizontal (90o) and vertical (0o) orientations and much less so to diagonal orientations

Question 7

What are the different levels of vision?

Answer 7

1. Foveal/central: 1-5 degrees
2. Parafoveal: up to 8 degrees
3. Peripheral: beyond 8 degrees

Question 8

What is eccentricity?

Answer 8

The angle between where you are looking at and areas in your periphery

Question 9

What are the features of central vision?

Answer 9

• Highest visual resolution
• Colour perception
• Focused attention

Question 10

What are the features of Parafoveal vision?

Answer 10

• Supporting reading and scanning
• Peripheral preview for focus shift

Question 11

What are the features of peripheral vision?

Answer 11

• Detecting motion
• Spatial awareness
• Low light sensitivity

Question 12

What did To et al. (2010) find about factors that affect crowding?

Answer 12

• Investigated how well pts can see diffs in images when they are presented alone (A), amongst identical flakers at close distance (B), amongst repetitions of a different flanker at mid distance (C), and amongst several flankers at far distance (D)
• Flankers made no diff in central vision but led to significant crowding in the periphery
• Most effective flankers were those similar to the targets