Deck 7: Visual Physiology

Question 1

Which one of the following statements about temporal responses is not correct?

A) It refers to a cell's receptive field location.
B) A cell with a sustained (tonic) temporal response has a relatively high level of activity during the presence of a stimulus.
C) A cell with a transient (phasic) temporal response shows a brief change in activity at stimulus onset and offset, but relatively little activity during constant stimulation.
D) Midget and parasol ganglion cells have different temporal responses.

Answer 1

A

Question 2

Which description of partial decussation is incorrect

A) Means that each LGN receives input from only one eye.
B) Is a property of the optic nerve.
C) Occurs at the optic chiasma.
D) Means that each cortical hemisphere receives input from the contralateral half of the visual field.

Answer 2

A

Question 3

Which one of the following is the correct term to describe the process in which a cell is excited when light falls in one part of its receptive field, and inhibited when light falls in another part?

A) spatial opponency
B) binocularity
C) sustained temporal response
D) transient temporal response

Answer 3

A

Question 4

Which one of the following is not associated with the functional architecture of striate cortex (V1)?

A) ocular dominance columns
B) orientation columns
C) blobs
D) Cytochrome oxidase stripes

Question 5

Which statement is correct? Simple cells:

A) Have a receptive field that can be mapped into excitatory and inhibitory zones.
B) Are not orientation selective.
C) Respond well regardless of exact stimulus position in the receptive field.
D) Are the most common type of cortical cell.

Question 6

Which one of the following statements about bipolar cells is not correct?

A) Bipolar cells transmit action potentials.
B) ON bipolars are activated by an increase in the photon catch of receptors.
C) OFF bipolars are activated by a decrease in the photon catch of receptors.
D) Some bipolars connect only to cones, others connect only to rods.

Question 7

Which of the following terms is the correct name for a class of retinal cell whose axons spread laterally across the retina, making contact with several photoreceptors.

A) Amacrine cells
B) Cone bipolar cells
C) Rod bipolar cells
D) Horizontal cells

Question 8

Which area of visual cortex contains the highest proportions of motion and disparity selective cells?

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

Question 9

Lesions affecting which visual cortical area usually result in a complete loss of visual function in the affected area?

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

Question 10

Beyond striate cortex a number of visually responsive cortical areas have been identified on the basis of several criteria, which one of the following is not one of these criteria?

A) topographic organisation
B) relative size
C) anatomical connections
D) cell response properties

Question 11

Cortical cells demonstrate many different forms of stimulus selectivity, which one of these is not associated with striate cortex?

A) orientation tuning
B) direction selectivity
C) binocularity
D) optic flow

Question 12

How many layers of cell nuclei does the retina contain?

A) 2
B) 3
C) 4
D) 5

Question 13

Which one of the following statements describes the Stiles-Crawford effect?

A) Photons arriving near the edge of the pupil are less likely to be absorbed.
B) Photons are some frequencies are less likely to be absorbed by a photoreceptor than those at other frequencies
C) Only two-thirds of the photons absorbed by a photoreceptor actually result in a response
D) When a photon is absorbed, its effect on a photoreceptor is the same regardless of the photon's wavelength.

Question 14

Which one of the following are not ganglion cells?

A) Amacrine
B) Biplexiform
C) Bistratified
D) Midget
E) Parasol

Question 15

Which of the following statements about chromatic opponency is incorrect?

A) spectral opponency is restricted to peripheral vision
B) Bistratified ganglion cells show blue-yellow opponency
C) Parasol ganglion cells do not show spectral opponency
D) Midget ganglion cells show red-green opponency

Question 16

Which ganglion cell class is the most numerous and responds only at high light levels?

A) parasol ganglion cell
B) bistratified ganglion cell
C) midget ganglion cell
D) biplexiform ganglion cell

Question 17

Where do approximately 90% of ganglion cell fibres project?

A) Suprachiasmatic nuclei
B) Pretectum
C) Lateral geniculate nuclei
D) Superior colliculi

Question 18

Which one of the following is not an important feature of the LGN's layered structure?

A) eye of origin
B) ganglion cell type
C) topography
D) Photoreceptor type

Question 19

Which one of the following is not a cell layer in the LGN?

A) Magno.
B) Bipolar.
C) Parvo.
D) Konio.

Question 20

In which visual cortical area are cells grouped according to speed and disparity preference?

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