Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

NBEO Part 1 > Vision Science > Flashcards

Vision Science Flashcards

(79 cards)

Start Studying
1
Q

Which retinal cell types undergo graded potentials?

A
  1. Photoreceptor cells
  2. Bipolar cells
  3. Horizontal cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which retinal cell types undergo action potentials? (2)

A
  1. Amacrine cells
  2. Ganglion cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the term for inability to recognize faces?

A

Prosopagnosia

  • inferotemporal (IT) cortex plays a role in facial recognition
  • visual area 4 and IT are close proximity and very common for a patient with prosopagnosia to also suffer from achromatopsia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Akinetopsia

A

cannot see movement in visual field
* lesion to the middle temporal cortex (MT) which is important for processing of motion stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Color agnosia

A

Difficulty associating colors with specific objects
Example: can’t remember that bananas are yellow even though they can visually perceive the color yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the Brucke-Bartley effect describe?

A

A flickering stimulus at 10 Hz appears brighter than a non-flickering light with the same average luminance

This effect also applies to stimulus presentation duration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the Troxler effect?

A

A phenomenon where surrounding background blends together when fixating on a point in space

This effect can cause a perceived disappearance of a smaller square when fixating on an ‘X’ in its center.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens during the Troxler effect when a patient is tested with the FDT visual field?

A

The entire field may appear to go gray

Patients should be informed to blink if this occurs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which part of the retina is most sensitive to flicker?

A

The peripheral retina

This sensitivity is due to the magno system, which is known for good temporal resolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the Granit-Harper law?

A

As the log of the area of the stimulus increases, the critical flicker fusion frequency also increases

This law explains why larger stimuli are more likely to be perceived as flickering.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why does the peripheral retina have increased chances of detecting flicker?

A

Larger stimuli take up more area of the retina, increasing chances of detection due to increased summation

The peripheral retina’s receptors exhibit increased summation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens to stabilized retinal images at low temporal frequencies?

A

They are unable to be detected

Blood vessels on the photoreceptors are stable relative to the retina.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a Purkinje tree?

A

The shadows cast by blood vessels on the retina when a penlight is rapidly moved against the eyelid

The penlight must move to visualize the shadows due to sufficient temporal frequency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Fill in the blank: The peripheral retina is part of the __________ system.

A

magno

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or False: The Troxler effect can cause a patient to perceive a uniformly-colored large square.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the primary visual system used in dim illumination?

A

Scotopic system

The scotopic system is mediated by rods, which provide heightened sensitivity to low light but poor acuity and color vision.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the peak spectral sensitivity of the scotopic system?

A

507 nm

This wavelength indicates the maximum sensitivity of rods in low light conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the primary visual system used in bright light?

A

Photopic system

The photopic system is dominated by cones and allows for high acuity and color discrimination.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the peak spectral sensitivity of the photopic system?

A

555 nm

This wavelength indicates the maximum sensitivity of cones in well-lit conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the visual acuity range for scotopic vision?

A

-20/200

This indicates poor visual acuity under low light conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the visual acuity range for photopic vision?

A

-20/20

This indicates excellent visual acuity under bright light conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does Ricco’s law state about stimulus detection?

A

Threshold number of quanta is constant

Ricco’s law describes the reciprocal relationship between stimulus intensity and stimulus area for detection below a critical diameter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the mathematical expression of Ricco’s law?

A

IA-K

Where I is stimulus intensity, A is stimulus area, and K is a constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does Weber’s Law deal with?

A

Just noticeable difference

Weber’s Law relates the difference threshold to the original stimulus intensity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the mathematical expression of Weber's Law?
K = delta I / I ## Footnote Where K is Weber's constant, delta I is the difference threshold, and I is the original stimulus intensity.
26
What does Bloch's law apply to?
Temporal summation ## Footnote Bloch's law relates to stimuli that are separated by time and their combined effects on perception.
27
What is the critical period for the scotopic system according to Bloch's law?
100 msec ## Footnote This is the time frame within which stimuli must be presented to maintain threshold detection.
28
What is the critical period for the photopic system according to Bloch's law?
10-50 msec ## Footnote This shorter time frame reflects the faster processing in bright light conditions.
29
What is the mathematical expression of Bloch's law?
I*t = K ## Footnote Where I is stimulus intensity, t is stimulus duration, and K is a constant. I and t are inversely proportional.
30
Scotopic vision is primarily mediated by which type of photoreceptor in the retina?
Rods * under dim illumination, rely on rods to maximize visual sensitivity
31
Scotopic vision occurs under what lighting conditions?
Dim illumination
32
Photopic vision occurs in what lighting conditions?
Bright light *dominated by cones *good visual acuity (~20/20) *color discrimination
33
Which 3 types of retinal cells undergo “graded” potentials?
Bipolar cells Horizontal cells Photoreceptor cells
34
The FIRST synapse in the visual pathway occurs in which layer of the retina?
Outer plexiform layer
35
Studies have demonstrated the implication of which type of cell damage in the early stages of glaucoma?
Magno cells * larger diameter, greater risk of glaucomatous damage prior to smaller neurons parvo cells
36
Neuron cells that respond to high temporal frequencies
Magno cells
37
Scotopic vision is mediated primarily by which type of photoreceptor in the retina?
Rods
38
Metamers
Two stimuli appear the same but are physically different * scalar property of metamers states that if intensities of metamers are increased or decreased equally, they will remain metamers
39
Cone photoreceptors are organized in which arrangement in the macula?
Hexagonal arrangement ## Footnote Cone photoreceptors are densely packed in a hexagonal arrangement in the macula.
40
What happens to the size and separation of cone photoreceptors as one moves peripherally in the retina?
They grow larger and more separated ## Footnote As the location moves peripherally, rods fill in the spaces between cones.
41
What type of photoreceptors fill in the spaces between cones in the peripheral retina?
Rods ## Footnote Rods fill in the spaces between cones as one moves peripherally in the retina.
42
The organization of the photoreceptor mosaic in the macula is optimal for what purpose?
Efficient visual processing ## Footnote The arrangement allows for efficient visual processing under a wide range of stimulus conditions.
43
How many photons are necessary to stimulate a rod photoreceptor?
1 photon ## Footnote One photon is absorbed by rhodopsin in the disc membrane, initiating a cascade of events.
44
How many photons must be experienced for a stimulus to be detected by a rod cell?
Around 10 photons ## Footnote This detection can occur through spatial summation or temporal summation.
45
What is the role of rhodopsin in rod photoreceptors?
Rhodopsin absorbs photons in the disc membrane of the outer segment ## Footnote Rhodopsin is essential for initiating the phototransduction cascade.
46
What are the two types of summation that can lead to stimulus detection in rod photoreceptors?
Spatial summation and temporal summation ## Footnote Both types of summation help accumulate sufficient photons for detection.
47
What are the five general classifications of virus structures?
Naked helical, enveloped helical, naked icosahedral, enveloped icosahedral, complex
48
Describe the appearance of helical viruses.
They appear like a tightly-coiled ribbon that can form a rod or resemble a telephone cord
49
Give an example of a helical virus.
Tobacco mosaic virus
50
What geometric shape does an icosahedral virus resemble?
A polyhedron with 20 equilateral triangular faces and 12 vertices
51
What is a capsomere?
The structural unit of a virus capsid, can be 5- or 6-sided
52
Provide an example of an icosahedral virus.
Adenovirus
53
What characterizes complex viruses?
They appear neither icosahedral nor helical and often have tails or complex outer walls
54
How are viruses further classified based on their genome?
By the type of nucleic acid: DNA or RNA, which may be single-stranded or double-stranded, linear or circular, segmented or not
55
True or False: Viral RNA can function as messenger RNA in some viruses.
True
56
Fill in the blank: Helically-shaped virions can form a _______.
[rod or telephone cord]
57
What are two stimuli that are physically different but appear to be the same called?
Metamers ## Footnote Metamers are important in color perception and vision science.
58
What is a dichromat?
A person who can adjust intensities of wavelengths so two separate patches appear the same ## Footnote Dichromats typically have a type of color vision deficiency.
59
What can a dichromat do with wavelengths A, B, and C?
Adjust the intensities of wavelengths B and C to appear identical to wavelength A ## Footnote This ability contrasts with trichromats, who cannot achieve the same result.
60
What are the three laws of Grassmann's laws of metamers?
Additivity property, scalar property, associative property ## Footnote These laws describe how metamers behave under different conditions.
61
What does the additive property of metamers state?
If you add an equal amount of a new wavelength to each metamer, they will remain metamers ## Footnote This property ensures that the identity of metamers is preserved under specific additions.
62
What does the scalar property of metamers state?
If the intensities of the metamers are increased or decreased equally, they will remain metamers ## Footnote This property highlights the resilience of metamers to uniform intensity changes.
63
What does the associative property of metamers explain?
If a metamer is substituted for another, the two metamers will still match ## Footnote This property allows for flexibility in color matching even with substitutions.
64
Fill in the blank: Wavelength A + B = _______.
Wavelength C + D ## Footnote This equation demonstrates the associative property of metamers.
65
Fill in the blank: Wavelength A = _______ + J.
Wavelength K ## Footnote This equation is part of the associative property demonstration.
66
Fill in the blank: Therefore, wavelength K + J + B = _______.
Wavelength C + D ## Footnote This shows how substitutions in metamers still yield matching results.
67
What are the types of pathways that transmit information from photoreceptors to the brain?
Magno-, parvo-, or koniocellular pathway. ## Footnote These pathways are responsible for processing different types of visual information.
68
What happens when a white stimulus is presented on a white background?
All mechanisms will be stimulated. ## Footnote No particular pathway is isolated in this scenario.
69
What effect does a blue stimulus on a yellow background have?
It suppresses the mid-range and long-range cones and selectively stimulates the blue/yellow opponent pathway. ## Footnote This pathway is also referred to as the koniocellular pathway.
70
Which pathway is readily isolated by a flickering target?
Magnocellular pathway. ## Footnote This pathway is most sensitive to flicker.
71
Fill in the blank: A _______ stimulus on a white background will not isolate any particular pathway.
white ## Footnote The presence of similar colors leads to stimulation of all mechanisms.
72
True or False: A blue stimulus on a yellow background activates all cone types equally.
False ## Footnote It specifically suppresses mid-range and long-range cones.
73
What is the primary sensitivity of the magnocellular pathway?
Sensitivity to flicker. ## Footnote This makes it ideal for isolating flickering targets.
74
What type of cell in the visual system has receptive fields that respond preferentially to dark and light edges or bars of specific orientation?
Simple cells ## Footnote Simple cells have receptive fields split into antagonistic inhibitory and excitatory areas.
75
Which type of cell prefers elongated stimuli of specific orientation but does not require the stimulus to be placed in a specific area of the receptive field?
Complex cells ## Footnote Complex cells respond to stimuli regardless of their placement within the receptive field.
76
True or False: The receptive fields of rod cells and ganglion cells possess a preference for stimulus direction.
False ## Footnote Rod cells and ganglion cells do not display any preference for stimulus direction.
77
What is the primary characteristic of the receptive fields of complex cells in relation to stimulus direction?
Preference for direction ## Footnote Complex cells respond to stimuli moving in a certain direction but not in the opposite direction.
78
Fill in the blank: The receptive fields of _______ do not possess inhibitory and excitatory regions.
complex cells ## Footnote This distinguishes complex cells from simple cells.
79
What do the receptive fields of amacrine cells, rod cells, and ganglion cells respond to?
Brightness intensities and spot sizes ## Footnote These cells do not show a preference for the direction of stimuli.

NBEO Part 1 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions