Deck 8: Vision: From Eye to Brain

Question 1

The _______ is (are) primarily responsible for refracting light to form an image on the retina.

A) cornea
B) lens
C) pupil
D) extraocular muscles

Answer 1

A

Question 2

The bending of light rays by the optical components of the eye is called

A) diffraction.
B) fractionation.
C) polarization.
D) refraction.

Answer 2

D

Question 3

The _______ muscles are essential for accommodation.

A) orbital
B) ciliary
C) extraocular
D) lentiform

Answer 3

B

Question 4

Which of the following is incorrectly paired?

A) Bipolar cells; graded potentials
B) Ganglion cells; action potentials
C) Horizontal cells; action potentials
D) Photoreceptors; graded potentials

Question 5

In the scotopic system, the relationship between the number of visual receptor cells and the number of ganglion cells demonstrates a _______ of information.

A) transduction
B) regression
C) convergence
D) divergence

Question 6

Which statement about rod receptors is false?

A) In the dark, rod receptors continually release neurotransmitter onto bipolar cells.
B) When light hits the photopigment, it triggers a cascade of chemical reactions that hyperpolarize the rod receptor.
C) Rods are concentrated outside the fovea.
D) Rods contain a special photopigment called S opsin.

Question 7

Quanta of light that enter the eye are captured in rod cells by

A) photons.
B) rhodan.
C) rhodopsin.
D) the iris.

Question 8

Which statement about photopic and scotopic vision is false?

A) The photopic system uses only cone receptors.
B) Rod receptors can be activated by weak light intensity because of their high sensitivity.
C) The receptive field of cone receptors outside the fovea is small.
D) There are more rods than cones in the retina.

Question 9

A high density of _______ is responsible for the dark color of the fovea, and this density is what make visual _______ so high in this area.

A) rods; refraction
B) cones; acuity
C) rods; blur
D) cones; variable

Question 10

Hawks have much better visual acuity than humans because they have

A) specialized cones for detecting detail.
B) specialized cones for detecting distance.
C) more densely packed cones in the fovea.
D) larger eyes relative to their body size.

Question 11

What is responsible for the lack of photoreceptors at the optic disc and consequent blind spot?

A) It is the location where blood vessels and ganglion cell axons leave the eye.
B) It is a location with a high density of pigment obscuring photoreceptor cells.
C) It is the location where parts of the two optic nerves cross the midline.
D) It is point of attachment for eye muscles.

Question 12

_______ of the pupils is associated with the use of drugs that block acetylcholine transmission, such as belladonna.

A) Myopia
B) Refraction
C) Constriction
D) Dilation

Question 13

Visual acuity is highest in the region of the retina called the

A) fovea.
B) optic disc.
C) lens.
D) iris.

Question 14

The optic disc is the

A) area of highest visual acuity in the retina.
B) area of the retina through which the axons of the ganglion cells exit.
C) area of the retina with the highest concentration of rods.
D) round opening of the eye through which light enters.

Question 15

The phenomenon of adaptation refers to

A) the constantly changing sensitivity of photoreceptors to light in order to match illumination levels.
B) the capacity of many photoreceptor cells to send signals to a single cell.
C) the sensitization of photoreceptors to light levels that are constant.
D) increases in the number of rods in response to increased length of time in darkness.

Question 16

_______ light and _______ convergence are properties of the scotopic system, whereas _______ light and _______ convergence are properties of the photopic system.

A) Dim; high; bright; low
B) Dim; low; bright; high
C) Bright; high; dim; low
D) Bright; low; dim; high

Question 17

At any given time, a photoreceptor operates approximately over a _______-fold range of brightness.

A) 10
B) 100
C) 1,000
D) 1 million

Question 18

Why is it best to look slightly off center to see a distant, dim star?

A) Light reaches rods directly in the periphery, without having to pass through layers of cells and blood vessels.
B) Cones are absent in the fovea and numerous in the retinal periphery, and are more sensitive than rods to dim light.
C) Rods are numerous in the fovea and absent in the retinal periphery, and are sensitive to dim light.
D) Rods are absent in the fovea and numerous in the retinal periphery, and are sensitive to dim light.

Question 19

People differ in their concentration of _______, and this variation may account for differences in _______ in different individuals.

A) cones; acuity
B) cones; peripheral vision
C) rods; acuity
D) rods; peripheral vision

Question 20

About half of the human V1 is devoted to the fovea and the retinal region surrounding it, thereby facilitating high acuity in the

A) entire visual field.
B) periphery of the visual field.
C) central part of the visual field.
D) upper portions of the visual field.

Question 21

Individuals with blindsight

A) are unable to detect trichromatic colors.
B) have no conscious perception of visual stimuli but are still able to discriminate better than would be predicted by chance alone.
C) have hallucinations within the region of injury.
D) perceive objects in space that are not present.

Question 22

Which pathway accurately describes the route for the passage of visual information to the brain?

A) Optic tract, optic nerve, optic radiations
B) Optic radiations, optic nerve, optic tract
C) Optic nerve, optic radiations, optic tract
D) Optic nerve, optic tract, optic radiations

Question 23

Which statement regarding visual fields is true?

A) The left visual field projects to the eyes and then to the left cerebral hemisphere.
B) The right visual field projects to the eyes and then to the right cerebral hemisphere.
C) The left visual field projects to the left eye only, and then to both cerebral hemispheres.
D) The right visual field projects to the eyes and then to the left cerebral hemisphere.

Question 24

What features of the visual system of a prey animal, such as a rabbit, serve to better detect predators?

A) Their eyes are placed on the sides of the head, they have wide peripheral vision, and little overlap in their fields of vision.
B) Their eyes are proportionally large and they have pinpoint acuity, due to a density of cones in the fovea.
C) They have a wide field of vision due to the large overlap in their fields of vision.
D) They have smaller proportion of retinal fibers crossing the midline than predatory species do.

Question 25

Most axons of the retinal ganglion cells terminate in the

A) optic chiasm.
B) superior colliculus.
C) lateral geniculate nucleus.
D) primary visual cortex.

Question 26

When light hits the center of an off-center bipolar cell's receptive field, it _______ and releases _______ glutamate, which in turn _______ off-center ganglion cells.

A) depolarizes; more; hyperpolarizes
B) hyperpolarizes; less; hyperpolarizes
C) depolarizes; less; depolarizes
D) hyperpolarizes; more; depolarizes

Question 27

An on-center/off-surround cell responds most strongly when

A) both its the center and surround are illuminated.
B) a spot of light illuminates part of its center.
C) the center of its receptive field is illuminated.
D) a spot of light illuminates part of its surround.

Question 28

In the retina, when illuminated, cone receptors that connect to an on-center bipolar cell cause _______ in the on-center bipolar cell.

A) a depolarization
B) a hyperpolarization
C) an action potential
D) no change

Question 29

In _______ cells, light falling in the center of the cell causes excitation, and light falling in the surround causes inhibition.

A) on-center/on-surround
B) on-center/off-surround
C) off-center/on-surround
D) off-center/off-surround

Question 30

The boundaries of visual objects are enhanced through the process of

A) visual acuity.
B) spatial-frequency.
C) lateral inhibition.
D) extrastriate perception.

Question 31

Hubel and Wiesel's theoretical model has been characterized as a _______ model of cortical visual processing.

A) spatial-frequency filter
B) hierarchical
C) human-recognition
D) receptive-field

Question 32

Which statement describes the spatial-frequency model?

A) More complex receptive fields are built up from inputs of simpler ones.
B) Spectrally opponent cortical cells contribute to the perception of color.
C) The visual system analyzes the number of cycles of light-dark patches in any stimulus.
D) The tendency of rods and cones to adjust their light sensitivity to match ambient illumination.

Question 33

Damage to cortical area V5 results in an inability to perceive

A) color.
B) motion.
C) orientation.
D) form.

Question 34

Cells in brain area _______ respond to illusory contours.

A) V1
B) V2
C) V3
D) V4

Question 35

In area V5 of the visual cortex, cells appear to be sensitive to

A) form.
B) wavelength.
C) motion.
D) orientation.

Question 36

The human visual system responds within very narrow range of the electromagnetic range: from about _______ nanometers.

A) 1 to 100
B) 100 to 200
C) 400 to 700
D) 1,000 to 10,000

Question 37

The human visual system

A) can only detect high frequency, short wavelengths.
B) can only detect low frequency, long wavelengths.
C) detects all wavelengths.
D) detects light within a narrow range of the electromagnetic range.

Question 38

Which property is not a dimension of color perception?

A) Brightness
B) Complexity
C) Hue
D) Saturation

Question 39

When you look at the blue sky on clear day, your perception of the blue color is produced by

A) long-wavelength photons.
B) short-wavelength photons.
C) infrared rays.
D) gamma rays.

Question 40

Which statement about color perception is true?

A) The trichromatic hypothesis is supported at the level of the retina.
B) The opponent-process hypothesis is consistent with current research on cones.
C) Spectrally opponent cells are found only in the eye.
D) Research has largely refuted both the opponent-process and the trichromatic theories of color perception.

Question 41

People with normal color vision have more _______ receptors than _______ receptors, and the precise proportions of these receptors _______ among individuals.

A) S; M; can vary
B) S; M; are always the same
C) L; M; can vary
D) L; M; are always the same

Question 42

The _______ hypothesis proposed that there are separate receptors in the retina sensitive to blue, green, and red.

A) opponent-process
B) spectrally opponent
C) dichromatic
D) trichromatic

Question 43

In _______ cells, two different regions of the light spectrum have opposite effects on firing response.

A) dichromatic
B) trichromatic
C) spectrally opponent
D) ganglion

Question 44

When a gene carrying a third photopigment was introduced into photoreceptors of adult male squirrel monkeys with dichromatic vision, the monkeys

A) gained the ability to discriminate short-wavelength stimuli (blue) from long-wavelength stimuli (not blue).
B) lost the ability to discriminate short-wavelength stimuli (blue) from long-wavelength stimuli (not blue).
C) gained trichromatic vision.
D) gained yellow-blue discrimination.

Question 45

In the monkey LGN, 70-80% of the cells are spectrally opponent, while very few spectrally opponent cells are found in the cat LGN. This may be the reason that monkeys

A) cannot detect the color of rapidly-moving objects, while cats can.
B) cannot distinguish black and white as well as cats can.
C) cannot distinguish bright colors as well as cats can.
D) can distinguish colors easily, while cats cannot.

Question 46

Genes for the M and L pigments are on the X chromosome, and males have only one X chromosome, while women have two. This explains why

A) men are more likely than women to have visual impairments.
B) women are more likely than men to have visual impairments.
C) women and men are about equally likely to have visual impairments.
D) the incidence of visual impairments is most affected by age.

Question 47

The dorsal stream system of visual processing is said to specialize in processing information about

A) "what."
B) "who."
C) "when."
D) "where."

Question 48

The ventral stream system of visual processing is said to specialize in processing information about

A) "what."
B) "how."
C) "when."
D) "where."

Question 49

The most likely effect of damage sustained to the dorsal stream is

A) color blindness.
B) optic ataxia.
C) the inability to recognize familiar faces.
D) blindsight.

Question 50

What was the proposition that helped to explain why patient D. F. could not perceive objects but could reach for and hold for objects in her visual field?

A) There is one visual processing stream that is responsible for identifying, locating, and guiding movements toward objects.
B) There are two primary visual processing streams; one responsible for identifying objects, and one for processing visual information surrounding the object of interest.
C) There are two primary visual processing streams; one responsible for identifying objects, and one for locating objects and guiding movements toward them.
D) There are three primary visual processing streams; one for identifying objects, one for identifying faces, and one for all other visual stimuli.

Question 51

If an individual were to experience bilateral damage at the junction of the occipital and temporal cortex, the likely result would be loss of

A) color vision.
B) the ability to detect motion.
C) the ability to recognize common objects.
D) the ability to grasp objects by their center of mass.

Question 52

A patient enters the ER after a near-drowning episode. He was without oxygen for a significant period of time, and an MRI scan showed bilateral damage to the border between the occipital and temporal lobes. Which symptom would you expect this patient to display?

A) The inability to name common objects or familiar people
B) The inability to follow a laser pointer moving on a screen
C) The inability to differentiate between red and green
D) The presence of a scotoma in both the right and left visual field

Question 53

Recent research suggests myopia may be caused by

A) too much sun.
B) too much reading and close-up visual activities.
C) indoor lighting.
D) genetic influences.

Question 54

Amblyopia is best treated with

A) dark glasses.
B) surgical correction and an eye patch.
C) more time outdoors.
D) corrective lenses.

Question 55

The most common age-related cause of vision loss is

A) color blindness.
B) myopia.
C) amblyopia.
D) macular degeneration.

Question 56

In vertebrates, the _______ is primarily responsible for fine-tuning refraction.

Question 57

The photopigment in rods that responds to light is called _______.

Question 58

Dilation of the pupils is controlled by the _______ division of the nervous system.

Question 59

In _______, the interconnected neurons inhibit adjacent cells, resulting in contrast at the edge of regions.

Question 60

According to the _______ model, the visual system analyzes the number of cycles of light-dark (or color) patches in any stimulus.

Question 61

In some insects, the _______-wavelength receptors respond to ultraviolet wavelengths that humans cannot see.

Question 62

The _______ hypothesis of color perception states there are three different types of cones, and each one is excited by a different part of the spectrum and each has a separate pathway to the brain.

Question 63

In _______, individuals can identify objects, but have trouble using their vision to reach for and grasp them.

Question 64

In the condition called _______, the eyeball is too long, causing the cornea and lens to focus images in front of the retina instead of on it.

Question 65

In the condition called macular degeneration, the region of the eye that is damaged is the _______.

Question 66

Create a short paragraph using the following terms: fovea, cones, rods, center of visual field, retinal periphery, acuity, receptive fields, light

Question 67

Outline how the optic disc relates to the blind spot.

Question 68

Explain the three ways the eye responds to the vastly different light intensities it encounters.

Question 69

Discuss the two basic types of retinal receptive fields found in bipolar cells and ganglion cells, and LGN.

Question 70

Explain the spatial-frequency model of visual processing.

Question 71

Which wavelengths of light are detected by the human visual system? Provide an example of an organism that can detect wavelengths of light that humans cannot.

Question 72

Which theory of color perception has been best supported by what we now know about cones? How has that theory also been shown to be insufficient?

Question 73

Differentiate the dorsal stream from the ventral stream.

Question 74

What is amblyopia and how is it treated?

Question 75

What is macular degeneration? Describe the differences between "dry" macular degeneration and "wet" macular degeneration? Which type is more common? Which type is more severe?

Question 76

Identify and describe the cells of the retina and discuss the pattern of their interconnections.

Question 77

Compare and contrast the properties of the human photopic and scotopic visual systems.

Question 78

Describe the opposing effects of glutamate on bipolar cells and how these effects relate to lateral inhibition.

Question 79

Describe the ways that the cells of the retina interact to produce and enhance the boundaries of visual objects.

Question 80

Describe the differences between a hierarchical and spatial-frequency model of vision.