Striate Cortex (M2)

Question 1

What type of processing occurs from complex cell wiring?

Answer 1

hierarchical processing

Question 2

What is the pathway of neurons in the striae cortex for konio neurons?

Answer 2

konio to layer 2/3

Question 3

For simple cells, what occurs if the slit of light covers a small part of the excitatory and inhibitory region (wrong orientation)?

Answer 3

no response

Question 4

Where does the LGN receive inhibitory input from (and what does this do)?

Answer 4

1. feedback inhibition from visual cortex
2. mesencephalic reticular formation (saccadic suppression)
3. inter-neurons within LGN (magno can inhibit parvo neurons)

Question 5

What is different about complex striate cells compared to simple cells? 1. What is the same? 2

Answer 5

1. bar of light can stimulate the cell at many different locations within a relatively large receptive field
2. respond best to a bar of light of a given orientation

Question 6

Throughout the cortical levels of the striae cortex, the columns of cells show what kind of sensitivity? 1. What do neighboring columns show? 2

Answer 6

1. same orientation sensitivity

2. a slight shift in orientation preference

Question 7

What are the type of cells that respond best to a bar of light that moves through the receptive field in a certain direction and not at all in the opposite direction called?

Answer 7

directionally-selective complex cells

Question 8

What are the most common cells in the striae cortex?

Answer 8

complex cells

Question 9

For simple cells, what occurs if the slit in the proper orientation but in the surround?

Answer 9

1. response of light OFF

2. could result in decrease in spontaneous activity while light ON

Question 10

Why do simple cells show simpler behavior than complex cells?

Answer 10

they are closer in the circuit to the LGN input neurons

Question 11

What are the type of cells that have an optimum length of stimulus in addition to orientation, position and sometimes direction of movement called?

Answer 11

end-stopped cells

Question 12

Which layer of the striae cortex shows no orientation sensitivity? 1. Why? 2

Answer 12

1. layer 4

2. cells receive input from LGN neurons and have center-surround receptive fields

Question 13

What is the pathway of neurons in the striae cortex for magno neurons?

Answer 13

1. magno to 4Cα

2. 4Cα to 4B

Question 14

For simple cells, what occurs if the light covers all of the excitatory and inhibitory region (diffuse light)?

Answer 14

no response

Question 15

What are the cells in the striate cortex that have their receptive field elongated along a particular axis within an ON- or OFF-center and antagonistic surround?

Answer 15

simple cells

Question 16

Where is the first point in the visual pathway where info from OD and OS is combined? 1. So what processing info begins here? 2

Answer 16

1. striae cortex

2. binocular phenomenon like stereopsis

Question 17

What is the relationship between orientation and ocular dominance columns in the striae cortex?

Answer 17

they run at a right angle to each other

Question 18

What are the typical responses of the receptive fields for neurons in layers 4B and 2/3 of the striate cortex?

Answer 18

cortical processing

Question 19

Which of the pathways is involved in color “blobs”?

Answer 19

parvo pathway

Question 20

If an electrode was inserted so that it traveled in a given cortical layer parallel to the surface, what is seen in terms of ocular dominance?

Answer 20

would cycle from OD dominance to OS dominance and back

Question 21

Where do most LGN neurons project to? 1. What layer do most of the axons from the LGN project to? 2

Answer 21

1. striae cortex

2. layer 4C

Question 22

What is the pathway of neurons in the striae cortex for parvo neurons?

Answer 22

1. parvo to 4Cβ

2. 4Cβ to 2/3

Question 23

What are the typical responses of the receptive fields for neurons in layers 4C of the striate cortex?

Answer 23

1. concentric center-surround receptive fields

2. driven by one eye only