mono: temporal vision

Question 1

Spatial vision is concerned with changes in luminance across _________

Answer 1

Space

Question 2

Temporal vision is concerned with changes in luminance over ________

Answer 2

Time

Question 3

A temporal sinusoid manifests a sinusoidal change in ___________ ______ _____

Answer 3

Luminance over time

Question 4

Will a temporally modulated stimulus of low modulation depth (contrast) be resolved? How will it appear?

Answer 4

It may not be resolved, appears steady

Question 5

Will a temporally modulated stimulus of high modulation depth (contrast) be resolved? How will it appear?

Answer 5

It may be resolved, appears as flickering

Question 6

A low temporal frequency stimulus may be seen as flickering at a _______ rate

Answer 6

Low

Question 7

A higher temporal frequency stimulus may appear to flicker at a ___________ rate

Answer 7

Higher

Question 8

Temporal frequency is typically given in what units?

Answer 8

Hertz (Hz)

Question 9

1 Hz is equal to

Answer 9

1 cycle per second

Question 10

As the temporal frequency is increased, a frequency is reached at which flicker can no longer be resolved. What is that frequency called?

Answer 10

The critical flicker fusion frequency (CFF)

Question 11

Once a frequency is reached that cannot be resolved, how will the stimulus appear?

Answer 11

Steady

Question 12

The CFF represents the _______________________ of the visual system for a given modulation depth

Answer 12

High temporal resolution limit

Question 13

The CFF can be thought of as ________ acuity

Answer 13

Temporal

Question 14

How is CFF impacted with an increase in retinal illuminance?

Answer 14

Increases linearly

Question 15

CFF is considerably higher under _________ compared to _________, conditions

Answer 15

Photopic compared to scotopic, conditions

Question 16

The CFF increases _________ with the log of the retinal illumination

Answer 16

Linearly

Question 17

What does the Ferry-Porter law state?

Answer 17

That CFF is proportional to luminance of flickering stimulus

Question 18

For foveal cones only, as the intensity of the test stimulus is increased, our perception of flicker __________

Answer 18

Increases

Question 19

How are CFFs for differing wavelengths in Photopic luminance?

Answer 19

CFFs are the same for different wavelengths in Photopic luminance

Question 20

For Photopic luminance: Flickering lights with equal luminance but different wavelengths have _________ critical flicker frequencies

Answer 20

Equal

Question 21

At low luminance, CFFs are the highest for _____________ wavelength stimulus. Why?

Answer 21

Shorter

Because at low luminance rods absorb better at shorter wavelengths

Question 22

CFF _______ with the log of stimulus area.

Answer 22

Increases

Question 23

A stimulus which appears steady in the central vision may appear flickering in the periphery. Why?

Answer 23

Due to higher temporal resolution of the peripheral retina for higher luminance

Question 24

Where is CFF the highest?

Answer 24

Mid-peripheral retina at high luminance

Question 25

At ____º eccentricity, the CFF is maximum (90 Hz)

Answer 25

35º

Question 26

How does this compare to foveal CFF?

Answer 26

Twice as high as foveal CFF

Question 27

For low luminance, the CFFs remains ___________ with the retinal location

Answer 27

Fairly constant

Question 28

Temporal vision is characterized by the _______

Answer 28

TMTF - Temporal modulation transfer function

Question 29

Stimuli that fall outside of the TMTF are seen as ____________

Answer 29

Fused or steady (not resolved temporally)

Question 30

Stimuli that fall under the TMTF graph are ____________

Answer 30

Resolved temporally and perceived as flickering

Question 31

TMTF shows maximal sensitivity to ___________ frequencies and reduced sensitivity to _________ and ________ frequencies

Answer 31

Max - moderate ## Footnote Reduced - lower and higher

Question 32

For the TMTF, the high-frequency cutoff represents the highest temporal frequency that can be resolved at _______________

Answer 32

100% modulation

Question 33

At low modulation depth, how does the stimulus appear?

Answer 33

Steady

Question 34

At high modulation depth, how does the stimulus appear?

Answer 34

Flickering

Question 35

At high temporal frequency, how does the stimulus appear?

Answer 35

Flickering until it reaches the CFF

Question 36

In the TMTF curve, the reduction in low-frequency temporal sensitivity tells us that ___________ changes in illumination are not seen

Answer 36

Very gradual

Question 37

Two examples of the Troxler phenomenon

Answer 37

1. Sunset 2. Minute hand on a watch

Question 38

The manifestation of the visual system's reduced sensitivity to low temporal frequencies is the inability to perceive stationary or stabilized retinal images, called the _______________________

Answer 38

Troxler Phenomenon

Question 39

How can we explain the reduction in sensitivity to low temporal frequencies?

Answer 39

the phase lag between center and surround signals in ganglion cells can cancel each other and reduce sensitivity

Question 40

The high-frequency TMTF cutoff is due to what?

Answer 40

Neural constraints

Question 41

The faster a neural system responds and the more transient its response, the ____ is its temporal resolution.

Answer 41

Greater

Question 42

As a stimulus's temporal rate ___________, a frequency is eventually reached where the neural response is neither fast nor transient enough to allow resolution.

Answer 42

Increases

Question 43

Masking phenomena provide information regarding both _______ and _________ processing of visual information

Answer 43

Spatial and temporal

Question 44

A ________ reduces the visibility of a stimulus referred to as the ________

Answer 44

Mask ## Footnote Target

Question 45

3 types of visual masks

Answer 45

Simultaneous masking Backward masking Forward masking

Question 46

With simultaneous masking, the mask and target are what?

Answer 46

Present at the same time

Question 47

Simultaneous masking is more pronounced in what individuals?

Answer 47

Amblyopic patients

Question 48

Because of simultaneous masking, an amblyopic eye's visual acuity may be _________ when measured with a standard eye chart than with isolated optotypes

Answer 48

Worse

Question 49

The reduction in acuity caused by surrounding spatial patterns is sometimes referred to as the _____________

Answer 49

Crowding phenomenon

Question 50

How does crowding impact visual acuity performance?

Answer 50

Reduces VA compared to no crowding

Question 51

In backward masking, the ________ precedes the ________

Answer 51

Target precedes the mask

Question 52

In backward masking, how does the mask impact the visibility of the target?

Answer 52

Reduces visibility

Question 53

What is a form of backward masking where the mask and target are spatially adjacent?

Answer 53

Metacontrast

Question 54

In forward masking, the _______ precedes the ________

Answer 54

Mask precedes the target

Question 55

What is referred to as paracontrast?

Answer 55

Forward masking where the target and mask are spatially adjacent

Question 56

How can flickering light impact retinal blood vessels?

Answer 56

Cause dilation of the retinal blood vessels

Question 57

How is temporal contrast sensitivity impacted with amblyopic patients?

Answer 57

Reduced at all temporal frequencies

Question 58

Flicker-defined form perimetry can aid in the diagnosis of what?

Answer 58

Primary open angle glaucoma

Question 59

Data obtained with ocular hypertension (elevated IOPs with normal visual fields) reveal abnormalities at _______ and ________ TMT frequencies.

Answer 59

Moderate and high ## Footnote Suggests that temporal sensitivity may be an early indicator of ganglion cell loss.