retina to cortex

Question 1

lateral geniculate nucleus

Answer 1

• located in the thalamus
• has 6 layers

Question 2

optic chiasm

Answer 2

where the nerves from each eye meet

Question 3

LGN layers 1 & 2

Answer 3

magnocellular layers from m ganglion cells

Question 4

layer 3-6 of LGN

Answer 4

parvocellular layers from p ganglion cells
- process shape and color

Question 5

contralateral layers

Answer 5

• receive information from opposite eye
• 1,4,6

Question 6

ipsilateral layers

Answer 6

• receive from the same side eye
• 2, 3, 5

Question 7

koniocellular layers

Answer 7

involved in specialized color input from k ganglion cells

Question 8

two visual pathways

Answer 8

1. dorsal
2. ventral

Question 9

dorsal pathway

Answer 9

where/how pathway which does spatial and motion information

Question 10

ventral

Answer 10

• what pathway
• object recognition, color

Question 11

Primary visual cortex (V1)

Answer 11

• aka striate cortex
• has 200 millio cells
• where circular receptive fields turn into striped ones

Question 12

retinotopic mapping

Answer 12

relative placement of where things are in the visual cortex

Question 13

cortical magnification

Answer 13

makes it so that objects in the middle of our field of view will occupy a larger part of the cortex than the peripheral
- more neurons process in center than in the peripheral

Question 14

visual crowding

Answer 14

objects in peripheral have much lower resolution than those in central vision so its hard to detect things in our peripheral that are cluttered

Question 15

types of neurons in V1

Answer 15

1. simple cells
2. complex cells

Question 16

simple cells

Answer 16

respond bets to bars of light or dark and have a particular oritnetation preference and location preference

Question 17

complex cells

Answer 17

respond to bars of light or dark with a orientation preference but dont need a specific location
- good for moving bar
- usually bigger field

Question 18

David Hubel and Torsten Wiesel

Answer 18

• discovered striped receptive fields while playong with a cat

Question 19

end stopped

Answer 19

some cells in V1 also have a preference for length.
the preferred length will be the whole receptive field and when it gets longer it decreases

Question 20

V1 columns

Answer 20

• columns with preferred orientations
• columns for each eye

Question 21

selective adaptation

Answer 21

a technique where we can selectively deactivate groups of neurons through adaptation by presenting a stimulus for an extended perior of time
- ex: titled bars

Question 22

comparing visual areas by

Answer 22

• the tupes and distributions of neurons in that area
• other areas they connect to
• properties which they are tuned to
• retinotopic map

Question 23

dorsal stream

Answer 23

diffuse–> m-ganglion–> magnocellular layer –> v1 –> v2 –> MT –> parietal cortex

Question 24

ventral pathway

Answer 24

midget –> p ganglion –> parvocellular layer –> V1 –> V2 –> V4 –> inferotemporal
- object regocnition

Question 25

visual agnosia

Answer 25

inability to recognise objects by their shape despite having normal vision and IQ

Question 26

manual estimation

Answer 26

using the distance between index and thumb to estimate the size of an object they can see

Question 27

grasp calibration

Answer 27

adjust the distance between thumb and index as you reach to grasp it

Question 28

optic apraxia

Answer 28

affects the dorsall stream - couldnt grasp to pick it up but can esrimate its size

Question 29

V4

Answer 29

processes color, edges and curvatures - contour selective

Question 30

inferotemporal cortex

Answer 30

processes objects, faces and places

Question 31

3 parts of the inferotemporal cortex

Answer 31

1. fusiform face area 2. parahippocampal place area: places and layouts 3. extrastriate body: full body and parts

Question 32

grandmother cell hypothesis

Answer 32

- thought that we have specific neurons for indentifying specific people - more likely distributed coding: combinations