Vision

Question 1

What in vision is different in mammals?

Answer 1

Spatial field

Question 2

What is co processing

Answer 2

When visual information goes into the brain with many co processing

Question 3

What is the optic chiasm?

Answer 3

At the optic chaism the point where the optic nerve crosses and go to the rear of the brain to visual cortex

Question 4

What does the visual cortex do?

Answer 4

Visual cortex fuses the information together to make a 3 dimensional image

Question 5

What is peripheral vision

Answer 5

your side vision, the ability to see things outside of your direct line of sight.

Question 6

What is the axons on the retinal neurones called?

Answer 6

ganglion cells

Question 7

What does ganglion cells do?

Answer 7

Carry information from optic nerve to optic chaism

Question 8

Types of lesions in visual pathway

Answer 8

lesion in the optic nerve causes total loss of vision
lesion in the optic chaism causes loss of half of the visual hemifield
lesion in the optic tract causes loss of vision to the opposite half of the hemifield

Question 9

3 types of visual perception

Answer 9

Low level- colour, contrast
Medium level- shape discrimination, surface depth
High level-object identification

Question 10

What does visual perception have to be integrated with

Answer 10

Focus, Light and movement control

Question 11

What does stimulating retina allow for?

Answer 11

Stimulating retina allows for the recording of activity in the visual cortex

Question 12

What pathway is involved in recognition?

Answer 12

Ventral pathway is involved in recognition

Question 13

Retinal ganglion cell

Answer 13

Retinal ganglion cell is connected to different cell types which communicate with photoreceptors

Question 14

Retinal eccentricity

Answer 14

The area of the retina on which light is focused influences visual acuity, which is sharpest when the object is projected directly onto the central fovea

Question 15

Ocular dominance

Answer 15

Ocular dominance refers to the preferential use of one eye when performing monocular activities

Question 16

Ocular dominance columns

Answer 16

Left and right eyes form columns to allow better integration

Question 17

LGN(Lateral geniculate nucleus)

Answer 17

LGN in 2 signals(p and M channel) sends information to the visual cortex layer 4c

Question 18

Two types of processing in vision

Answer 18

serial allows only one object at a time to be processed, whereas parallel processing assumes that various objects are processed simultaneously

Question 19

Tritonopia

Answer 19

lost of blue pigment

Question 20

What can go wrong with cone pigment in genetics?

Answer 20

Crossover from parents goes wrong causes incorrect gene structure causing problems with vision

Question 21

dichromate

Answer 21

Loss ff a gene

Question 22

Intragenic recombination

Answer 22

Anomalous trichromats(gene)

Question 23

Types of cone pigments

Answer 23

S, M and L

Question 24

What happens with rhode light

Answer 24

When rhode light comes in rhodopsin switches on the g protein. G protein activates phosphodesterase which catalyses for the destruction of cyclic GMP turning it into GMP which leads to closure of the channel
When continuous light occurs there is a big shut down of channels which leads to low calcium in the cell. There is then high affinity for cyclic GMP, therefore channels open up again. Process can adapt to continuous light.

Question 25

Photoadaptation

Answer 25

When continuous light occurs there is a big shut down of channels which leads to low calcium in the cell. There is then high affinity for cyclic GMP, therefore channels open up again. Process can adapt to continuous light.