Neuro

Question 1

splitting of optic chiasm would result in what?

Answer 1

bitemporal hemianopsia and loss of stereo for uncrossed disparity along the midline

Question 2

Some people who have ocular albinism have….

Answer 2

Complete decussation which could result in strabismus and no stereopsis

Question 3

macular sparing means…

Answer 3

part of the field goes past the macula

Question 4

what part of the brain detects disparities larger than +/-2 degrees around the vertical midline?

Answer 4

Corpus collosum

Question 5

Where is the central visual field represented?

Answer 5

posterior LGN

Question 6

Where is the periphery visual field represented?

Answer 6

Anterior LGn

Question 7

Where is the superior visual field represented?

Answer 7

lateral-inferior LGN

Question 8

Where is the inferior visual field represented?

Answer 8

medial-superior LGN

Question 9

Where are the parvocellular layers of LGN? What percent of retinal input does this make up?

Answer 9

Dorsal, layers 3-6
80% retinal input

Question 10

Where are the magnocellular layers of LGN? What percent of retinal input does this make up?

Answer 10

Ventral, layers 1-2
7-9%

Question 11

Where are the koniocellular layers of LGN?

Answer 11

Interstitial K1-K6

Question 12

What layers of the LGN have ipsilateral input?

Answer 12

Layers 2,3,5

Question 13

What layers of the LGN have contralateral input?

Answer 13

1,4,6

Question 14

What categories of Hubel and Wiesel are monocular?

Answer 14

Type 1 and 7

Question 15

What column has the highest proportion of monocular neurons?

Answer 15

4C

Question 16

What is another name with position coding?

Answer 16

positional disparity (in eye)

Question 17

What is meant by phase coding?

Answer 17

No positional disparity but ON/OFF receptive fields are different

Question 18

What percent of V1 neurons are binocular?

Answer 18

over 50% but not in IVCa or IVCb

Question 19

What percent of neurons in V1 foveal and parafoveal are binocular?

Answer 19

97%

Question 20

two reciprocal neurons

Answer 20

Near (NE)
Far( FA)

Question 21

disparity tuned neurons

Answer 21

Tuned zero (To)
Tuned Inhibitory (TI)
Tuned Near (TN)
Tuned Far (TF)

Question 22

What are flat neurons?

Answer 22

Binocular neurons that are not disparity selective

Question 23

Percentages of foveal and parafoveal binocular neurons found

Answer 23

Disparity tuned (64%)
Flat (50%)
Reciprocal (16%)

Question 24

Do near neurons show higher response in crossed or uncrossed disparities?

Answer 24

crosses disparity

Question 25

Do far neurons show higher response in crossed or uncrossed disparities?

Answer 25

uncrossed disparity

Question 26

What are far and near reciprocal neurons involved with?

Answer 26

vergence initiation

Question 27

What kind of stimuli does To (Tuned zero) and TI (tuned inhibitory) prefer?

Answer 27

Prefer stimulus on the horopter. They are inverse of each other.

Question 28

What do To (Tuned zero) and TI (tuned inhibitory) neurons have roles in?

Answer 28

Fixation maintenance and stereoacuity

Question 29

What kind of stimuli does TN (Tuned near) and TF (tuned far) prefer?

Answer 29

Prefer stimuli near the horopter but not on the horopter.

Question 30

What does TN (Tuned near) and TF (tuned far) play a role in?

Answer 30

Vergence initiation
Fixation maintenance

Question 31

What percent of V2 neurons respond to disparity?

Answer 31

70%

Question 32

Where would you find cytochrome oxidase stripes?

Answer 32

In the V2 area.

Question 33

What are the thick stripes in the v2 shown to be selective for? What kind of input is it?

Answer 33

Largely magnocellular input.
Disparity and motion
Low spatial frequency, high temporal frequency

Question 34

What are the pale stripes in the v2 shown to be selective for? What kind of input is it?

Answer 34

Parvocellular input
Fine stereopsis, good for detecting high spatial frequency, low temporal frequency

Question 35

What kind of input is the thin stripes in the V2?

Answer 35

Parvocellular input via blobs

Question 36

In v3, how many neurons respond to disparity?

Answer 36

50%

Question 37

What does v3 respond to?

Answer 37

Static disparity

Question 38

Where is v5 found? What is it specific for?

Answer 38

Middle temporal cortex
Specific for motion and binocular disparity.

Question 39

What is specific for optic flow neurons and gives information about self-motion?

Answer 39

MST (Middle superior temporal area) (V5)

Question 40

If a person has difficulty grasping with their hand, where could the lesion be?

Answer 40

PPC (Posterior parietal cortex)