18-1 To 18-7

Front 1

If I give you a dim stimulus, it won't take much of an increase in brightness to see a difference, but if I give you a bright stimulus, it will take a much larger increase in brightness to see a difference" These are common terms for what law?

Back 1

Weber's law

Front 2

What is the definition of threshold for a forced choice method?

Back 2

Halfway between 50 and 100%

Front 3

What variable in the Steven's power law changes depending on what is being measured?

Back 3

the exponent b

Front 4

What does signal detection theory try to remove from the determination of threshold?

Back 4

criterion

Front 5

Is signal detection theory used clinically? Why?

Back 5

No, signal detection theory takes forever

Front 6

What are the two ways a person can be right in signal detection theory

Back 6

1. hit
2. correct rejection

Front 7

What are the two ways a person can be right in signal detection theory

Back 7

1. miss
2. false alarm

Front 8

What d' value is considered to mean that one cannot distinguish between signal and noise?

Back 8

d'=0

Front 9

What d' value is considered threshold?

Back 9

d'=1

Front 10

Name two ways to manipulate a patients criterion?

Back 10

1. change the payoff
2. ?

Front 11

Where is hue discrimination best?

Back 11

Hue discrimination is best at wavelength blue-green (490nm) and yellow-red (590nm)

Front 12

What is the change in hue associated with the change in luminance?

Back 12

Bezold Brucke Effect

Front 13

In which three specific wavelengths of light is the hue not effected by the luminance?

Back 13

1. 478nm
2. 503nm
3. 578nm

Front 14

According to the Bezold Brucke effect stimuli below 500nm appear more _____ as instensity increases, while stimuli above 500nm appear more _____ as intensity increases.

Back 14

According to the Bezold Brucke effect stimuli below 500nm appear more blue as instensity increases, while stimuli above 500nm appear more yellow as intensity increases.

Front 15

If a neutral density filter transmits 10% of the light incident upon it, what is its optical density?

Back 15

Front 16

What do you the system of color-stimulus notation in which an attempt has been made to have the notation correspond to the sensory experience given?

Back 16

Munsell color system

Front 17

In the Munsell color system 100 different hues are evenely spaced where?

Back 17

100 different hues are uniformly spaced around the circumference of the circle

Front 18

Which system of color-stimulus notation has attempted to make the notation correspond to the sensory experience given?

Back 18

Munsell color system

Front 19

Of the three subjective attributes of the Munsell color system, which subjective attribute refers to the reflectance of the sample and is related to brightness

Back 19

value

Front 20

Would a value of 10 at the top of the Munsell cylinder be darker or lighter?

Back 20

10 is completely dark
0 is completely light

Front 21

Where do you find the most pure or highest chroma value on the Munsell cylinder? What would that value be?

Back 21

The greater the radius from the center of the cylinder the higher the chroma or more pure. 14 denotes the highest purity further out, while 0 would be the least pure further in.

Front 22

Munsell notation uses a pseudofraction to quantify the three subjective attributes, in what order are these attributes presented?

Back 22

H/V/C

Front 23

What do you call the monochromatic hues arranged around the perimeter of the CIE diagram?

Back 23

spectral locus

Front 24

If I mix equal amounts of 510nm and 560nm, where should I place the point M, indicating the resultant mixture?

Back 24

First draw a line between the two wavelengths on the spectral locus, then since they are mixed in a one to one ratio, place M halfway in between

Front 25

What two points do I connect to draw the line indicating the dominant wavelength?

Back 25

The resultant mixture M and the theoretical equal mixture at x=0.33 and y=0.33 W (white).

Front 26

What is the excitation purity of equal mixtures of two wavelengths?

Back 26

a=the distance between M and the dominant wavelength at the spectral locus, relative to the total distance from W to the spectral locus
b-relative distance between M and W, relative to the total distance from W to the spectral locus

Front 27

What do you call two colors on the CIE diagram that combine to form white?

Back 27

complementary colors

Front 28

What do you call the perceptual areas in the CIE diagram in which all colors will appear the same even if they are physically different?

Back 28

MacAdams Ellipses

Front 29

Which theory of color vision states that color information is coded by a limited number of cone types (perhaps 3), and the relative activities of these cone-types encodes color?

Back 29

Young-Helmholz a.k.a. Trichromatic theory

Front 30

What determines the hue in Opponent color theory?

Back 30

Front 31

What determines saturation in opponent color theory?

Back 31

Front 32

What determines brightness in opponent color theory?

Back 32

Front 33

1. Does Kollner's rule apply to congenital color defects?
2. Which are R/G color defects and which are B/Y

Back 33

1. Kollner's rule only applies to acquired color defects

Front 34

Name the potential conditions that would cause the indicated type of color deficiency in this general area.

Back 34

Front 35

What do you call the line formed by connecting the three primaries of the Nagel anomaloscope plotted on the CIE chromaticity diagram?

Back 35

Rayleigh equation

Hint 35

These correspond to a color confusion line shared by deuteranopes and protanopes

Front 36

What is varied in the top field of the Nagel anomaloscope and what is the range?

Back 36

The ratio of 670nm (red) light to 546nm (green) light is varied. 0 is defined as completely 546nm light, while 73 represents exclusively 670nm (red) light

Front 37

What does turning a knob change in the lower field of the Nagel anomaloscope? What is the range?

Back 37

Radiance is varied. Turning the knob to 0 represents very dim yellow, while turning the knob to 87 represents very bright yello.

Front 38

1) When asked to match the top mixture field with the lower test field, at what number does a normal trichromat set the upper mixture field?
2. Where does a normal trichromat set the lower test scale?

Back 38

45 on the mixture scale and 17 on the test scale

Front 39

Where does the normal trichromat set mixture and test fields and how does it appear to him?

Back 39

Front 40

What does a normal trichromat see on the Nagel anomaloscope for a setting at zero?
2. What will he see at 23? What will he see at 52?
3. What will he see at 73?

Back 40

1. 0=green
2. as you increase to 45 it gets more yellow
3. as you go from 45 to 73, the yellow gets more red.

Front 41

1. Where will a protanope adjust the test field luminance when matching short green stimuli of the mixture field?
2. Where will he set the test field when matching longer red stimuli of the mixture field?

Back 41

1. as bright as 35 since the short stimuli appear bright
2. as dim as 5 since the long stimuli appear dim

Front 42

When asked to match the mixture and test field, where would a deuteranomalous trichromat set the mixture field knob?

Back 42

He'll probably set it lower than 45, maybe around 20 since he needs more 546 nm light to make up for his missing M pigment.

Front 43

When asked to match the mixture and test field, where would a protanomalous trichromat set the mixture field knob?

Back 43

He would set the mixture knob higher than 45, maybe around 60, to increase the amount of 670nm wavelength to make up for his lack of L pigment.

Front 44

Where does a protanomalous trichromat set the test field stimulus?

Back 44

test field less than 15, becaue the protanomalous trichromat must add extra 670nm to the mixture field, the mixture field appears dimmer, and he must reduce the test field luminance to compensate.

Front 45

What type of color vision tests are desaturated D-15, Farnsworth D-15, and 100 hue test?

Back 45

arrangement tests

Front 46

Is the Desaturated D-15 test more or less sensitve than the regular D-15 test?

Back 46

more sensitve, and especially useful for picking up subtle acquired defects like glaucoma

Front 47

What are the axes of the ROC (receiver operating curve)?

Back 47

Front 48

How do you define the colorimetric purity?

Back 48

Front 49

What does Grassman's law of additivity state?

Back 49

Front 50

What does Grassman's scalar law state?

Back 50

Front 51

Are Landholt C or Landholt ring recognition or resolution acuity tests?

Back 51

Front 52

Is minimum separable acuity a resolution or recognition acuity test?

Back 52

Front 53

1. How small is the lower limit of human resolution?
2. How small can a letter be and still be visible?

Back 53

Front 54

A letter E is 5mm in height and displayed at a distance of 10m. What visual angle does the letter subtend?

Back 54

Front 55

What is the logMar score for 20/20 visual acuity?

Back 55

Front 56

What is the logmar acuity for 20/20-1 Snellen?

Back 56

Front 57

What is the formula for diameter of the airy disc produced by optical diffraction of a point source object?

Back 57

Front 58

What states that two objects will be resolved when their separation is equal to the radius of the airy disc?

Back 58

Front 59

How wide can you make a line before you can detect if it's present or not?

Back 59

minimum separable and resolution acuity are 30 seconds of arc or 1/2 a minute

Front 60

1. What do you call all tasks that require you to localize one part of a target relative to another part of the target?
2. Can you name two examples of this type of acuity?

Back 60