Visual System Part 2

Question 1

Lateral geniculate nucleus

Answer 1

takes information from retinal ganglions and send it to the visual cortex
may also send information to other parts of the brain: blindsight

Question 2

Suprachiasmatic nucleus

Answer 2

regulates wake/dark cycle

sends information to pineal gland

Question 3

Pretectum

Answer 3

controls pupil size

Question 4

Superior colliculus

Answer 4

controls eye movements

Question 5

Fixation points

Answer 5

area of interests the eyes move to

Question 6

Saccades

Answer 6

rapid ballistic movements

Question 7

smooth pursuit

Answer 7

following moving objects

Question 8

vergence

Answer 8

distance adjustments

Question 9

vestibular-ocular

Answer 9

adjustment for head movements

Question 10

Eye tracking

Answer 10

identifies what eyes look at

Question 11

How is eyetracking useful for neuroscience

Answer 11

allows a very precise motor movement
no body movement
can be performed with skull exposed

Question 12

Optic chiasm

Answer 12

where nerves coss

Question 13

What is the order for when light enters the eye

Answer 13

axons cross over in the optic chiasm to the lateral geniculate nuclei and then up to the primary visual cortex, then the secondary cortex, and finally the extrastriate cortex

Question 14

where does information from the left visual field go?

Answer 14

the right thalamus and visual cortex

Question 15

Where does information from upper visual field go?

Answer 15

to lower ventral parts of visual cortex

Question 16

Where does information from central/foveal visual field go?

Answer 16

posterior visual cortex

Question 17

How is the LGN organized?

Answer 17

in 6 layers

Question 18

Magnocellular cells

Answer 18

Layer 1 and 2
Big and fast cells
mainly detects movement and is made up of mostly rods

Question 19

Parvocellular cells

Answer 19

Layer 4-6
Small and slow cells
mainly detects colour, patterns,and detail and is made up of mostly cones

Question 20

Koniocellular cells

Answer 20

in between layers and receives information from blue cones

Question 21

Which layers are ipsilateral

Answer 21

1,4,6

Question 22

Which layers are contralateral

Answer 22

2,3,5

Question 23

What’s the point of LGN

Answer 23

its the first point where information from both eyes are combined
visual receptive fields grow at this point and thus they get the bigger pictures from all the fields

Question 24

Visual radiation

Answer 24

band of tissues leaving the LGN and going to the visual cortex

Question 25

How is the visual cortex divided

Answer 25

Primary cortex = V1 = striate cortex Secondary cortex = V2 = Prestriate cortex V2, V3, V4, V5/MT = extrastriate cortex

Question 26

Primary visual cortex

Answer 26

25% of surface area devoted to the fovea | Receptive fields of cells in this area are larger than LGN and rectangular and organized into layers

Question 27

Where do koniocellular, magnocellular, and parvocellular cells project to?

Answer 27

IVa and IVc

Question 28

Simple V1 Cells

Answer 28

similar to LGN cells can detect lines of a specific orientation in a specific location Monocular

Question 29

Complex V1 cells

Answer 29

can detect lines of a specific orientation in any location binocular but one eye usually dominates motion sensitive

Question 30

Hypercomplex V1 cells

Answer 30

respond to lines in a particular orientation that end in a particular point in the receptive field some respond to lines of a specific orientation binocular but usually one eye dominates

Question 31

V1 Columns

Answer 31

all the cells in one column have similar receptive field regions, orientations, and dominant eyes Simple cells are on the surface while complex and hypercomplex cells are deeper within

Question 32

What happens if you examine a row

Answer 32

The visual field and the orientation shifts systematically | eye dominance shifts as well

Question 33

What measures colours

Answer 33

Blobs which are zones that cover many oriental columns and do not respond to orientation located in layer 2,3 5,6

Question 34

Module

Answer 34

Final level of organization within V1 | contains columns of all orientation and a blob

Question 35

How does the brain form these columns/modules?

Answer 35

Visual cortex organization depends on experience and is plastic

Question 36

Critical period

Answer 36

changes that are often especially relevent for a particular stage in development

Question 37

Ocular dominance

Answer 37

relative proportion of columns dominated by open eye

Question 38

Scomata

Answer 38

area of poor acuity/detection in visual field | occurs after damage to retina, optic nerve, LGN, or V1

Question 39

Personality scotoma

Answer 39

inability to perceive personality traits in themselves that are obvious to others