Deck 4: Central Visual Pathways

Question 1

The optic nerves provide the brain with

A) only color information.
B) only black and white information.
C) raw material for visual perception.
D) none of these

Answer 1

raw material for visual perception.

Question 2

Chiasm comes from the Greek word meaning

A) "between."
B) "cross."
C) "together."
D) "separate."

Answer 2

"cross."

Question 3

The fibers of the optic nerve from the _________ part of the retina cross over to the opposite (contralateral) part of the brain at the _________.

A) temporal; optic chiasm
B) nasal; optic disk
C) nasal; optic chiasm
D) temporal; optic disk

Answer 3

nasal; optic chiasm

Question 4

The _________ visual cortex processes information from the __________ visual field.

A) right; left
B) frontal; right
C) left; left
D) right; central

Question 5

Approximately 80 percent of the axons of ganglion cells project to the

A) optic chiasm.
B) lateral geniculate nucleus.
C) superior colliculus.
D) none of these

Question 6

The primary function(s) of the superior colliculus

A) is in guiding eye movements.
B) is in visual orienting reflexes.
C) is neither is in guiding eye movements nor is in visual orienting reflexes
D) are both is in guiding eye movements and is in visual orienting reflexes

Question 7

Sound and sight can reinforce each other in the visual system. They do this through

A) the presence of auditory cells in the optic nerve.
B) multisensory cells in the superior colliculus.
C) visual cells' output to the temporal lobe.
D) multisensory cells in the lateral geniculate nucleus.

Question 8

The LGN is part of the

A) thalamus.
B) midbrain.
C) cerebral cortex.
D) where pathway.

Question 9

In humans, the LGN on each side of the brain contains how many layers?

A) six
B) five
C) four
D) two

Question 10

Which one of the following is NOT a layer of the LGN?

A) magnocellular
B) parvocellular
C) retinotopic
D) all of these

Question 11

Which of the following descriptions is a property of the receptive fields of the LGN?

A) The surround is as inhibitory as the surround of a retinal ganglion cell.
B) They amplify or accentuate differences in illumination.
C) They prefer borders or contours of particular orientations.
D) all of these

Question 12

The layers of the lateral geniculate nucleus preserve the topography of the retina in

A) contralateral layers.
B) ipsilateral layers.
C) all layers.
D) the first two layers.

Question 13

The receptive fields of the lateral geniculate nucleus have a(n)

A) circular shape.
B) rectangular shape.
C) orientation-specific layout.
D) diagonal layout.

Question 14

In the lateral geniculate nucleus, parvocellular cells can be distinguished from magnocellular cells by

A) the shapes of their receptive fields.
B) the eye from which they receive input.
C) their response selectivity for color.
D) all of these

Question 15

Which of the following characteristics is NOT true of cells in the parvocellular layers of the LGN?

A) differentially sensitive to color
B) have smaller receptive fields than those of cells in the magnocellular layers
C) respond to rapid fluctuations of light intensity
D) give little response to uniform illumination

Question 16

Which cells respond best to abrupt fluctuations and rapid motions of light?

A) complex cells
B) parvocellular cells
C) hypercomplex cells
D) magnocellular cells

Question 17

The lateral geniculate nucleus

A) receives input from the visual cortex.
B) receives input from the reticular activating system.
C) both receives input from the visual cortex and receives input from the reticular activating system
D) neither receives input from the visual cortex nor receives input from the reticular activating system

Question 18

The visual cortex is located in the brain's

A) occipital lobe.
B) frontal lobe.
C) temporal lobe.
D) all of these

Question 19

Patches of blindness within a person's visual field are termed

A) visual voids.
B) visual windows.
C) scotomas.
D) retinal blanks.

Question 20

The __________ of the retina is disproportionately represented in its projection area at the visual cortex, a phenomenon called ___________.

A) periphery; cortical misrepresentation
B) fovea; cortical magnification
C) inferior portion; cortical magnification
D) nasal part; visual amplification
E) all of these

Question 21

The primary visual cortex is also referred to as

A) striate cortex.
B) V1.
C) Area 17.
D) all of these

Question 22

Which of the following is a function of the visual cortex?

A) integration of input from the two eyes
B) orientation selectivity
C) direction selectivity
D) all of these

Question 23

Human V1 contains approximately

A) one million cells (1 x 106).
B) 125 million cells (1.25 x 108).
C) 250 million cells (2.5 x 108).
D) one billion cells (1 x 109).

Question 24

The sensation of seeing flashing spots and lines in response to electrical stimulation of the visual cortex is referred to as

A) phosphenes.
B) the ambiguity problem.
C) integration of local features.
D) none of these

Question 25

"Blindsight" refers to

A) cortically blind people's ability to use sound cues for orienting.
B) cortically blind people's ability to identify the location of a light they can't see because of cortical damage.
C) residual visual abilities following retinal damage.
D) visual illusions in cortically blind people.
E) all of these.

Question 26

Simple cells respond preferentially to

A) orientation.
B) direction of motion.
C) both orientation and direction of motion
D) neither orientation nor direction of motion

Question 27

Complex cells respond optimally to

A) orientation.
B) direction of motion.
C) both orientation and direction of motion
D) neither orientation nor direction of motion

Question 28

Cortical visual cells are generally very much like ganglion and lateral geniculate nucleus cells in

A) orientation selectivity.
B) direction selectivity.
C) receptive field shape.
D) none of the these.

Question 29

A __________ cortical visual cell will respond to a properly oriented stimulus anywhere within its receptive field.

A) simple
B) damaged but viable
C) complex
D) miniature

Question 30

The range of orientation selectivity of V1 neurons is

A) ± 5 degrees.
B) ± 10 degrees.
C) ± 15 degrees.
D) ± 20 degrees.

Question 31

Visual acuity typically is least for

A) obliquely oriented lines.
B) horizontally oriented lines.
C) vertically oriented lines.
D) all of these.

Question 32

Amblyopia refers to

A) vision for moving stimuli.
B) color sensitivity of cortical cells.
C) visual loss that cannot be corrected optically.
D) visual distortion associated with ambling.

Question 33

The preference of certain cells in V1 to display a preference for the input from one eye is referred to as

A) hypercolumn.
B) binocular disparity.
C) ocular dominance.
D) none of these.

Question 34

The tendency for binocular cells to have a more vigorous response to information from one of the two eyes is called

A) binocular integration.
B) monocular separation.
C) ocular dominance.
D) both monocular separation and ocular dominance

Question 35

Most cells in the visual cortex are

A) monocular.
B) binocular.
C) different in their left and right eye preference for orientation and direction.
D) both monocular and different in their left and right eye preference for orientation and direction

Question 36

Neurons in the blob regions of the visual cortex

A) are specialized for processing color information.
B) receive input from the magnocellular pathway.
C) show strong preference for contour orientation.
D) are unresponsive to visual stimulation.

Question 37

The aggregation of adjacent columns that cover a complete range of stimulus orientations and ocular dominance is referred to as

A) hypercolumn.
B) binocular disparity.
C) ocular dominance.
D) none of these

Question 38

If an electrode is driven perpendicular to the surface of the cortex through its layers, most cells will have the same preference for

A) direction.
B) motion.
C) size.
D) orientation.

Question 39

Optical imaging of the surface of the visual cortex while an animal views gratings of different orientations shows

A) movement of activity across the cortex as the gratings' bars move.
B) orientation columns whose width corresponds to the spatial frequency of the gratings.
C) activity in patches consistent with the size of hypercolumns.
D) all of these

Question 40

Position invariance refers to

A) the constant position of a region of visual space in different layers of the LGN.
B) the location of a part of the visual scene being isomorphic in different retinotopic maps.
C) the location of V1 being constant in different individuals' brains.
D) the constant response to a stimulus from anywhere within a cell's receptive field.

Question 41

The pathway that is concerned with the locations of objects in space and is sometimes referred to as the "where" pathway is known as

A) ventral stream.
B) temporal stream.
C) dorsal stream.
D) parietal stream.

Question 42

Lesioning the M pathway impairs an observer's ability to perceive

A) color.
B) texture.
C) acuity.
D) flicker.

Question 43

If Kevin had a permanent loss of color vision owing to damage to a portion of his brain, he would be experiencing

A) prosopagnosia.
B) achromatopsia.
C) akinetopsia.
D) aphasia.

Question 44

What is the inability to recognize previously familiar faces that can be caused by damage to the temporal lobe?

A) eccentricity
B) prosopagnosia
C) Purkinje shift
D) none of these

Question 45

Individual neurons in the visual cortex cannot accurately be called "feature detectors" because

A) there are not enough neurons to handle every possible feature.
B) individual cells cannot signal the presence of a particular stimulus feature with certainty.
C) both there are not enough neurons to handle every possible feature and individual cells cannot signal the presence of a particular stimulus feature with certainty
D) neither there are not enough neurons to handle every possible feature nor individual cells cannot signal the presence of a particular stimulus feature with certainty; visual cortical cells can act as "feature detectors"

Question 46

The fact that one can never be sure which stimulus has activated a cell is known as

A) phosphenes.
B) the ambiguity problem.
C) integration of local features.
D) none of these

Question 47

Intense stimulation of a cell for a period of time, resulting in temporary fatigue and a decrease in responsiveness, is called

A) tilt aftereffect.
B) adaptation.
C) prosopagnosia.
D) none of these

Question 48

An illusion in which a person experiences a temporary change in perceived orientation of lines is called

A) tilt aftereffect.
B) ambiguity problem.
C) direction selectivity.
D) perimetry.

Question 49

Sparse coding is consistent with

A) the high metabolic demands of V1 cells.
B) the ambiguity problem.
C) the small number of axons in the optic nerve.
D) the regularities of the visual scene.

Question 50

What role does the superior colliculus play in vision? How does it get the information it needs to provide this function?

Question 51

Given what is known about the lateral geniculate nucleus, what might be its functional role(s) in vision?

Question 52

Imagine a patient who, upon visual field testing, is unable to see light projected anywhere to the left of the point of fixation, regardless which eye is tested. What is your diagnosis and why?

Question 53

What receptive field properties emerge at the level of the visual cortex?

Question 54

What is a hypercolumn, and how does this concept relate to cortical magnification?

Question 55

Suppose you encounter a creature whose visual system contains only a P-pathway, not an M-pathway. How might this creature's visual world differ from yours?

Question 56

The information conveyed by any simple cell in the visual cortex is profoundly limited. Explain how and also explain how the visual system overcomes these limits.

Question 57

Why does a vertical line appear tilted slightly anticlockwise following prolonged exposure to lines tilted slightly clockwise?