BIO T4

Question 1

What is the role of the pretectum in the visual neural pathway?

Answer 1

reflex control of pupil and lens

Question 2

What is the role of the superior colliculus in the visual neural pathway?

Answer 2

orienting the movements of head and eyes

Question 3

What is the role of the hypothalamus in the visual neural pathway?

Answer 3

regulates the circadian rhythms

Question 4

Where is the concentration of rods and cones the highest across the retina?

Answer 4

• Rods in the periphery and in between the fovea and blind spot
• Cones in the fovea

Question 5

If you lost all of your cones, which of the following would likely occur?A) Loss of color visionB) Loss of peripheral visionC) Loss of night visionD) Loss of focused perception

Answer 5

A and D
| also light sensitivity

Question 6

Lateral inhibition describes

Answer 6

the reduced activity in one neuron induced by a neighbouring neuron that is active

Question 7

Which of the following statements best describes complex cells in the visual cortex?
a) They respond best to stationary stimuli.
b) They respond best to stimuli moving in a specific direction.
c) They are primarily involved in color perception.
d) They are sensitive to changes in brightness.

Answer 7

b

Question 8

Which type of retinal cell is primarily responsible for transmitting visual information from photoreceptors to ganglion cells?a) Bipolar cellb) Complex cellc) Amacrine celld) Horizontal cell

Answer 8

a| receives input directly from the receptors

Question 9

What is the primary function of end-stopped cells in visual processing?a) Detection of motionb) Perception of colorc) Recognition of facial featuresd) Detection of line orientation

Answer 9

d

Question 10

group of ganglion cell axons that exit through the back of the eye

Answer 10

optic nerve

Question 11

area at the back of the retina with no receptors

Answer 11

blind spot

Question 12

tiny area of the retina specialized for acute, detailed vision

Answer 12

fovea

Question 13

opening in the center of the iris where light enters

Answer 13

pupil

Question 14

law of specific nerve energies

Answer 14

rule that whatever excites a nerve always sends the same information to the brain

Question 15

ganglion cell

Answer 15

type of neuron in the retina that receives input from the bipolar cells

Question 16

blind spot

Answer 16

area at the back of the retina devoid of receptors

Question 17

neuron in the fovea of humans and other primates*

Answer 17

midget ganglion cell

Question 18

chemical contained in rods and cones that release energy when struck by light

Answer 18

photopigment

Question 19

horizontal cell

Answer 19

type of cell that receives input from receptors and delivers inhibitory input to*

Question 20

thalamic nucleus that receives incoming visual information

Answer 20

lateral geniculate nucleus

Question 21

receptive field

Answer 21

area in visual space that excites or inhibits any neuron

Question 22

small cell body with small receptive field in or near the fovea

Answer 22

parvocellular neuron

Question 23

large cell body with a large receptive field that is distributed evenly throughout the retina

Answer 23

magnocellular neuron

Question 24

area responsible for the first stage of visual processing

Answer 24

primary visual cortex (area V1)

Question 25

simple cell

Answer 25

cell that has a receptive field with fixed excitatory and inhibitory zones

Question 26

blindsight

Answer 26

ability to respond in limited ways to visual information without perceiving it consciously

Question 27

hypercomplex cell

Answer 27

cell that responds to a bar-shaped pattern of light in a particular orientation

Question 28

strabismus

Answer 28

condition in which the eyes do not point in the same direction

Question 29

What are cones for?

Answer 29

daytime lighting, or photopic conditions. 3 types of cones (with different photopigments)

Question 30

What are rods?

Answer 30

* nighttime lighting, or scotopic conditions. * Higher photopigment concentration. * More sensitive to light * (with different photopigments)

Question 31

Are there rods or cones in the retina?

Answer 31

There are no rods in the central fovea, but there are manymore rods than cones in the peripheral retina

Question 32

Explain the process of phototransduction

Answer 32

In rod cells in the dark, sodium-potassium-pump is in a depolarised state due to cGMP (glutamate release) --> When light hits rhodopsin channel, it activates transducin --> activates phosphodiesterase --> phosphodiesterase breaks down cGMP --> hyperpolarised cell + decreased glutamate release --> light stimulus! so rhodopsin is inactivated and via arrestin bound to rhodopsin transducin is blocked --> cell becomes depolarised + glutamate release until the next light impulse hits

Question 33

What is the reason for color vision deficiency?

Answer 33

People with certain genes fail to develop one type of cone,or develop an abnormal type of cone.

Question 34

What's the prevalence of colour blindness?

Answer 34

1 in 12*

Question 35

Which gene is responsible for red-green colour deficiency?

Answer 35

The gene causing red-green colordeficiency, is on the X chromosome.*

Question 36

What are parts of the parallel processing in the visual cortex?

Answer 36

* Ventral stream (towards temporal cortex): identifying and recognizing objects and faces. * Dorsal stream (towards parietal cortex): important for identifying where the objects are.

Question 37

What is the IT?

Answer 37

 : inferior temporal cortex recognizes objects -->

Question 38

What's visual agnosia

Answer 38

happens when the inferior temporal cortex is damaged and inhibits object recognition

Question 39

What is the role of the fusiform gyrus

Answer 39

recognising faces --> damage: prosopagnosia

Question 40

What is the MT?

Answer 40

Area MT: middle temporal cortex (=V5 area) --> responsible for processing visuospatial motion: inability to perceive or detect motion

Question 41

What happens if V4 is damaged?

Answer 41

 loss of color vision at the corresponding location in the visual field, visual attention and object recognition issues

Question 42

What is the MST?

Answer 42

middle superior temporal cortex * Motion perception * Damage leads to motion blindness

Question 43

Rods – 

Answer 43

* nighttime lighting, or scotopic conditions. Higherphotopigment concentration. More sensitive to light.

Question 44

vision in the fovea?

Answer 44

* daytime lighting, or photopic conditions. 3 types of cones (with different photopigments)

Question 45

In retinitis pigmentosa, early symptoms include the loss of peripheral vision and night vision. The loss of what type of cells couldlead to such symptoms?

Answer 45

rods

Question 46

What about people with maculardegeneration, which symptoms dothey have?

Answer 46

cones

Question 47

Name the hidden parts

Answer 47

Question 48

Name the hidden parts of the eye

Answer 48

Question 49

Name the hidden parts of the eye

Answer 49

Question 50

Which ten structures are part of the visual neural pathway?

Answer 50

1. Eye 2. Optic nerve 3. Optic chiasm 4. Hypothalamus 5. Optic tract 6. Pretectum 7. Superior colliculus 8. Lateral geniculate nucleus 9. Optic radiation 10. Striate cortex

Question 51

What happened if I cut the optic chiasm in the middle?

Answer 51

I'd see the right visual hemisfield only with the left eye and the left visual hemisfield only with the right eye

Question 52

What are the features of light?

Answer 52

Question 53

What is astigmatism?

Answer 53

Question 54

What is presbyopia?

Answer 54

Question 55

What is myopia?

Answer 55

Question 56

What is hyperopia?

Answer 56

Question 57

What are the layers of the fovea?

Answer 57

Question 58

What is the trichromatic theory?

Answer 58

We perceive colour through the relative rates of response by three kinds of cones, each one maximally sensitive to a different set of wavelengths.

Question 59

Which cone is missing?

Answer 59

Image as viewed by an observer lacking green cones (deuteranomaly)

Question 60

Which cone is missing?

Answer 60

Image as viewed by an observer lacking blue cones (tritanopia)

Question 61

Which cone is missing?

Answer 61

Image as viewed by an observer lacking red cones (protanopia)

Question 62

What are the odds of inheriting colour deficiency?

Answer 62

The gene causing red-green color deficiency, is on the X chromosome.

Question 63

Which visual cortex and other brain regions are implicated in vision?

Answer 63

Question 64

How does visual information process from the V1?

Answer 64

Question 65

What is the occipital lobe's, temporal lobe and ventral stream role in vision?

Answer 65

Question 66

explain the neurochemical processes underpinning vision

Answer 66