week 4 - visual pathways

Question 1

electronic map on V1

Answer 1

primary visual cortex

Question 2

retinotopic map

Answer 2

an electron map of the retina on the cortex

Question 3

cortical magnification

Answer 3

a small area of the fovea is represented by a large area on the visual cortex

Question 4

What techniques are used to research the retinotopic map and cortical magnification

Answer 4

brain imaging techniques such as PET and fMRI

Question 5

What part of the eye contains more cortex/neurons?

Answer 5

fovea

Question 6

Why do we have overrepresentation of the fovea on our visual cortex?

Answer 6

more detail and acuity is needed for more information

Question 7

Do we have cortical over-representaiton in our other senses?

Answer 7

in the somatosensory system, we have certain body parts that receive more information such as hands and face

Question 8

Why is the visual cortex also known as the striate cortex?

Answer 8

it is organized in columns

Question 9

What type of columns does the visual cortex contain?

Answer 9

• location columns
• orientation columns

Question 10

location columns

Answer 10

receptive fields at the same location on the retina are within the same column

Question 11

orientation columns

Answer 11

• neurons within columns fire maximally to the same orientation of stimuli
• adjacent columns change preference in an orderly fashion

Question 12

Describe Hubel’s and Weisel’s research regarding the primary visual cortex and columns.

Answer 12

• used recording electrodes to find neurons in the visual cortex
• pierced down from the surface of the cortex to showcase the receptor fields of each of the neurons they encountered

Question 13

What did Hubel and Weisel conclude with their research regarding the primary visual cortex and location columns?

Answer 13

Our visual cortex is organized in location columns. The receptive fields of neurons are stacked on top of each other, meaning they were all in charge of the same area.

Question 14

What did Hubel and Weisel discover after piercing through the surface in a vertical fashion?

Answer 14

Found that they were in a horizontal orientation

Question 15

What occurred when Hubel and Weisel moved the electrode obliquely through the location column?

Answer 15

all of the potential light bars or orientation are represented by different simple cortical neurons within that single location column

Question 16

hyper column

Answer 16

all the orientation columns within the location columns

Question 17

What is the purpose of a hyper column?

Answer 17

• receives all possible information that could potentially light up a specific location of retina
• well-suited for processing information from a small area of your visual field

Question 18

ocular dominance columns

Answer 18

neurons in the cortex respond preferentially to one eye

Question 19

tiling

Answer 19

columns working together to cover the entire visual field

Question 20

How do feature detectors respond to a scene?

Answer 20

tiling

Question 21

dorsal pathways

Answer 21

visual information is sent to parietal lobe

Question 22

ventral pathway

Answer 22

visual information is sent to temporal lobe

Question 23

What are the differences in visual information processing between the parietal and temporal lobe?

Answer 23

• temporal lobe processes what the information is
• parietal lob processes where/how the information is

Question 24

Describe Ungerleider and Mishkin experiment

Answer 24

1. animal is shown object and presented with two choice task
2. animal given reward for detecting target object
3. specific lobe is removed and animal is unable to recognize correct target object

Question 25

After the temporal lobe was removed, what ability did the animal lose?

Answer 25

was unable to recognize object discirmination

Question 26

After the parietal lobe was removed, what ability did the animal lose?

Answer 26

was not able to locate where the food was hidden after learning it in repeated trials

Question 27

What pathway is also called…

Answer 27

ventral pathway

Question 28

Where pathway is also called…

Answer 28

dorsal pathway

Question 29

What are similarities between the dorsal and ventral pathways?

Answer 29

• originate in retina and continue through two types of ganglion cells in LGN
• have some interconnection
• receive feedback from higher brain areas

Question 30

If someone damaged their temporal lobe, would they have more trouble naming and object or determining its location?

Answer 30

naming the object

Question 31

If someone damaged their parietal lobe, would they have more trouble naming and object or determining its location?

Answer 31

determining the object’s location

Question 32

Explain the streams for information about what and how for the patient whose ventral pathway was damaged by gas leak.

Answer 32

• not able to match orientation of card with slot
• able to match orientation if she was placing card in a slot
• evidence shows double dissociation between ventral and dorsal pathways

Question 33

module

Answer 33

a brain structure that processes information about a specific stimuli

Question 34

What does damage to the temporal lobe result in?

Answer 34

prospagnosia aka “face blindness”

Question 35

fusiform face area (FFA)

Answer 35

responds best to faces

Question 36

parahippocampul place area (PPA)

Answer 36

responds best to spatial layout

Question 37

extrasite body area (EBA)

Answer 37

responds best to pictures of full bodies and body parts

Question 38

H.M. and hippocampus

Answer 38

• removal of hippocampus decreased seizures but eliminated ability to form new memories
• suggests that hippocampus is possibly in charge of recognizing/remembering objects

Question 39

Greeble experiment

Answer 39

• training participants to Greeble results in an increase of areas of FFA response
• responds best to whatever someone is an expert in