Exam 3 - Week 7 to 9

Question 1

What retinal cones are functional for a Protanopic individual?

No Red (L cone) and cannot detect dark red preception, thus it is considered as nothing

Answer 1

Blue and Green

Question 2

What retinal cones are functional for a protanomalous?

Answer 2

Blue, Green and Green shifted

Question 3

What retinal cones are functional for a Deuteranopic?

Answer 3

Blue, Red and shifted to red (Missing Green cones)

Note: Has the highest frequency at 5%

Question 4

What retinal cones are functional for a Tritanopic?

Answer 4

Green and Red

Note: All blue is missing and is extremely rare.

Question 5

What retinal cones are functional for a Blue cone monochromcy?

Answer 5

Blue

Note: Cannot see color

Question 6

What retinal cones are functional for a Achromatopsia?

Answer 6

None

Note: Very rare. Usually congenital, photophobic, nystagmus, VA is 20/200 or worse (best corrected), usually found in family members

Question 7

What are the 3 inherited color blindness?

Answer 7

Monochromacy - Either Rod monochromat or Blue monochromat
Dichromacy - Protanopic, Dueteranopic and Tritanopic (two functional cones - which have color perception)
Anamolous trichromacy - Protanomolous and Dueteranomolous

Question 8

What island is known as the color blind?

Answer 8

Pengelapese, the ratio is 5% of the population is color blind

Note: An irish gave off the gene. Dogs have a similar form of color blindness

Question 9

Can an individual have a monochromacy but with issues to their cones?

Answer 9

Yes, the short wavelength is the only one function. They will pass ERG, Visual Field and EOG will be passed. GREEN AND RED ARE ABSENT

Note: Cannot distinguish hues and is an X linked recessive gene (1 out 1000 individual will have this)

Question 10

What is the percentage of blue cones in the retina?

Answer 10

2%, this is remarkable for monochromats.

Question 11

How many hues can a monochromat see?

Answer 11

100

Question 12

Which two dichromacy are sex linked?

Answer 12

Protanaopia and Deuteranopia (Usually in males)

Question 13

When we test for color blindness, which test is common practice?

Answer 13

Ishihara test

Question 14

What are the lines that go right through the CIE diagram for color?

Answer 14

Confusion line - shows where color confusion occur for Dichromats

Question 15

What are the 3 anomalous trichromacy?

Answer 15

Protanomoly
Duetranomoly - most common type (on test) (green shifted towards red)
Tritanomoly

Note: Most common. Will depend on shift of damage, they are inherited

Question 16

How do we test for most of color deficiencies in clinic?

Answer 16

Farnsworth test

Question 17

What is the function an Anomaloscope?

Answer 17

Finds the color deficiency and even further find out what subtype is actually missing.

Question 18

What is the difference between visual acuity and spatial acuity?

Answer 18

There is no difference. VA is the spatial resolving capacity of the visual system.

Note: It can also be the smallest spatial detail that can be resolved

Question 19

What part of the snellen “E” forms a small grating pattern?

Answer 19

Stroke

Note: There are 2.5 cycles of black and white (30 cycles for 20/20 vision)

Question 20

Whats the equivalent of 1 minute of arc?

Answer 20

6meters

Note: 6/6 = 20/20

Question 21

When measuring acuity, OD’s characterize VA as in “20/20” vision, but how do scientists measure VA?

Answer 21

Smallest Visual Angle of a cycle of grating

“The smaller the Visual Angle at which you can identify a cycle of a grating, the better your vision

Question 22

What formula do you use when you want to detect the smallest angle possible?

Answer 22

cpd = 1/2(arctan(s/2f))

Question 23

How many cones are needed when distinguishing Acuity?

Answer 23

2 is the minimum

Question 24

What is the typical VA in cycle degree?

Answer 24

30 cycles per degree

Question 25

True or False. If you have 3 or more cones, you will be able to distinguish the difference between spatial resolution?

Answer 25

True

Question 26

True or False, the higher the degree, the better the VA will become?

Answer 26

True

Question 27

What are 3 issues that affect VA?

Answer 27

Myopia, Hyperopia and Accommodated hyperopic eye

Question 28

True or False. Visual acuity is greater than Spatial acuity?

Answer 28

True

Question 29

When Dr. Cameron was showing the "Hyper Acuity", what is the difference vs. spatial acuity?

Answer 29

Hyper acuity is 5 to 10 times better

Question 30

What is size constancy?

Answer 30

Objects of known size tend to appear constant in size despite distance changes

Question 31

What is the maximum our vision can interrupt, in regards to degrees?

Answer 31

150/60 degrees

Question 32

What is the spatial frequency for 20/20 vision equivalent to?

Answer 32

30 degrees

Question 33

Can OKN be a good subjective measure for vision?

Answer 33

According to the VA suppression method

Question 34

What is the measurement for temporal frequency?

Answer 34

Hz Note: Measured as cycles/second

Question 35

What s the basic stimulus used to study temporal vision?

Answer 35

Flickering light

Question 36

What is the Ferry Porter law?

Answer 36

CFF increases lineraly with log BACKGROUND

Question 37

What is the Granit Harper law?

Answer 37

CFF increases lineraly with log STIMULUS area

Question 38

What is the scientific name for the "light house effect"?

Answer 38

Broca-Sulzer Note: Measure in lux and you notice information around 100 milliseconds @ 44.5 lux

Question 39

In regards to the critical flicker test: wagon wheel, what is the fusion flicker response at a stand still?

Answer 39

120 rpm

Question 40

True or False. You can increase your CFF rate by increasing their metabolic rate?

Answer 40

True

Question 41

True or False. There is an increase in CFF with animal size?

Answer 41

False. It will decrease.

Question 42

Of the 40 M diseases in the US, what are these disease that are clinically relevant in regards to CFFF?

Answer 42

Optic Neuritis MS Diabetic Retinopathy Sleep Apnea

Question 43

What is the Ferry Porter Law?

Answer 43

Noting that CFF is proportional to the logarithm of the luminance of flickering stimulus (L) INCREASES LINEARLY WITH LOG BACKGROUND

Question 44

What does the Granit-Harper law theory explain?

Answer 44

CFF increases linearly with log stimulus size or diameter

Question 45

True or False, CFFF increases with illumination?

Answer 45

False. Note: Plateau is around 40Hz, which is what the human eye can detect for flicker

Question 46

True or False. Only rods are distinguished at a larger test field?

Answer 46

False. Cone and Rods both require this. Note: As the TV screens get larger, the Hz needs to increase as well

Question 47

During color and orientation processing, what occurs to the temporal resolution and integration interval?

Answer 47

High Temp. res. | Short Integration interval

Question 48

During the binding process, what happens to the temporal resolution and integration interval?

Answer 48

Low temporal resolution Long integration interval Note: Pairing is used

Question 49

What is motion?

Answer 49

Movement or change in position or place d = vt

Question 50

What does Beta motion do?

Answer 50

switching motion from on and off (slower motion)

Question 51

What does Phi motion ?

Answer 51

A flicker occurs, goes on and then off(Rapid)

Question 52

If there is an after image and rotates in circle. You see the color, what kind of process is it?

Answer 52

Magno (creates an after image)

Question 53

What is Sigma Motion?

Answer 53

Flickering of a stripes, which look as though they are moving

Question 54

Where does motion perception occur the most in primates?

Answer 54

Cortex

Question 55

What is the visual pathway for Motion perception?

Answer 55

Parasol cells --> Magno cells --> v1 (mostly complex) --> MT --> MST

Question 56

What is the percentage of cells that are direction selective (complex)

Answer 56

25%

Question 57

True or False. All cells in the MT are direction selective?

Answer 57

False. Majority are direction selection but not all

Question 58

What is Akinetopsia?

Answer 58

Motion blindness

Question 59

What is relative size?

Answer 59

Judging due to past experiences but we try to use size constancy on our retina. Ie. Cars in the street

Question 60

What is size constancy?

Answer 60

Where an image be look the same size but in reality it is smaller than the object

Question 61

What is Familiar size?

Answer 61

From your past familiar images tell you to perceive an image but you cannot always trust it IE. Stealth bomber

Question 62

What is Linear perspective?

Answer 62

An angle that is smaller will be perceived smaller on the retina

Question 63

What is texture?

Answer 63

Relative size is the same but the perception is further and looks larger Ie. Checkered balls

Question 64

What is interposition?

Answer 64

Process of occulusion which blocks one item over another, therefore depth is created due to position Ie. King of spades behind King of clubs

Question 65

What is Clarity?

Answer 65

Form of interposition, acts as a depth cue. | Ie. Fogging of light house

Question 66

What is lighting and shadow?

Answer 66

Illumination and shadow cause an illusion of depth. Light and shadow are always opposite of one another, therefore an optic shadow is created which makes an image to perceive its either behind or in front. Ie. Mountain range with shadow

Question 67

What is the angle of declination below the horizon?

Answer 67

How big the angle relative to the horizon | d= h/tan(a)

Question 68

Angular declination is _______ in the prism condition

Answer 68

Increased

Question 69

True or False, Angular declination is decreased in the after effect condition?

Answer 69

True

Question 70

What type of function confirms that angular declination is a depth cue for distance judgement?

Answer 70

Monotonic

Question 71

What is motion parallax?

Answer 71

Both Monocular and Binocular vision, Objects that are further away tend to move slower, compared to the closer object. Note: You can fixate on object and it can be slower than without focusing on the object When you track something while driving

Question 72

What is Kinetic Depth Effect (KDE)

Answer 72

Illusion of depth is enhanced due to motion

Question 73

What is the definition of a psychophysical test?

Answer 73

Perception arise from a physical stimulus

Question 74

What are three psychophysical methodologies?

Answer 74

Threshold - VA, Contrast sensitivity Signal Detection - Visual Field, Weber's Law - the 2nd part of the line graph

Question 75

What is the smallest light intensity a pt. can detect test be considered?

Answer 75

Threshold

Question 76

What is Accuracy of the Threshold?

Answer 76

Correctly measuring the value Ex. IOP closer to one is more precise Note: MORE IMPORTANT THAN PRECISION

Question 77

What is Precision of the Threshold?

Answer 77

Repeatablility of measurement | Ex. IOP 15, 14, 16 is more accurate than 9, 12, 17

Question 78

Do ganglion cells have a constant steady state?

Answer 78

Yes. to depict homeostasis

Question 79

What are the variables for threshold variable?

Answer 79

Neural Noise, Patient (different approaches for all pts of their attention), Motivation and Fatigue

Question 80

What is the staircase approach?

Answer 80

Graded steps (usually equal) and ask the "do you see the spot on the background"

Question 81

What is Signal detection theory?

Answer 81

Model and data method for decision problems with uncertainty (noise) Note: Finds point of interest

Question 82

What type of eyecare is considered psychophysics?

Answer 82

Optometry

Question 83

If you the rows are equal in the Signal Detection, what does that mean?

Answer 83

No detection