Task 4 -On columns and pathways

Question 1

Contrast

Answer 1

the difference in luminance between an object and the background, or between lighter and darker parts of the same object

Question 2

Acuity

Answer 2

the smallest spatial detail that can be resolved at 100% contrast

Question 3

Cycle

Answer 3

for grating, a pair consisting of one dark bar and one bright bar

Question 4

Visual angle

Answer 4

the angle subtended by an object at the retina – the angle that would be formed by lines going from the top and bottom (or left and right, depending on orientation of the stripes) of the cycle on the page, passing through the center of the lends, and ending on the retina

Question 5

Two types of visual acuity:

Answer 5

1. The minimum resolvable acuity (the finest stripes that can be resolved)
2. the minimum recognizable acuity (the smallest letter that can be recognized)

Question 6

Minimum visible acuity

Answer 6

Refers to the smallest object one can detect

Question 7

Minimum resolvable acuity

Answer 7

refers to the smallest angular separation between neighboring objects that one can resolve

Question 8

Minimum recognizable acuity

Answer 8

refers to the angular size of the smallest feature that one can recognize or identify

Question 9

Minimum discriminable acuity

Answer 9

refers to the angular size of the smallest change in a feature (e.g., a change in size, position, or orientation) that one can discriminate

Question 10

Vernier acuity

Answer 10

the smallest misalignment that we can reliably discern

Question 11

Contrast sensitivity function (CSF)

Answer 11

a function describing how the sensitivity to contrast (defined as the reciprocal of the contrast threshold) depends on the spatial frequency (size) of the stimulus

Question 12

Contrast threshold

Answer 12

the smallest amount of contrast required to detect a pattern

A contrast of 100% corresponds to a contrast sensitivity value of 1