Slide 1

Question 1

What is the scope of human vision on the electromagnetic scale?

Answer 1

380-760 nanometers of wavelength

Question 2

What are photons

Answer 2

light rays

Question 3

True or false: we need light to see

Answer 3

true

Question 4

What is visual field?

Answer 4

The extent of visual space seen by each eye

Question 5

What is visual sensitivity?

Answer 5

the ability to detect changes in the levels of light

Question 6

What is visual acuity?

Answer 6

the ability to distinguish between two nearby points in space

Question 7

What is another word for visual acuity?

Answer 7

visual resolution

Question 8

What is visual transduction?

Answer 8

converting light energy into neural signals

Question 9

What is the advantage of having one eye on each side of the head?

Answer 9

larger visual field

Question 10

What is the advantage of having both eyes in front?

Answer 10

binocular disparity

Question 11

define binocular disparity

Answer 11

• difference in the position
• of the same image
• on two retinas
• helps the brain create depth perception

Question 12

function of binocular disparity

Answer 12

helps create depth perception

Question 13

What is the pupil

Answer 13

where light enters the eye

Question 14

What is the iris

Answer 14

• regulates amount of light

- entering the eye

Question 15

What is the lens

Answer 15

• changes its shape

- to focus image on the retina

Question 16

What are the ciliary muscles?

Answer 16

• connect to the lens

- change the shape of the lens

Question 17

What is the retina?

Answer 17

• formed of layers of cells
• light rays converted
• into neural signals

Question 18

What is used to convert light rays into neural signals?

Answer 18

photoreceptors

Question 19

What is the fovea area?

Answer 19

where visual acuity is the highest

Question 20

What are the 5 cell types of the retina?

Answer 20

• photoreceptors
• horizontal cells
• bipolar cells
• amacrine cells
• retinal ganlion cells

Question 21

Function of photoreceptors

Answer 21

convert light waves into neural signal

Question 22

Where does visual transduction occur?

Answer 22

photoreceptors

Question 23

Describe cones

Answer 23

• red
• more sensitive to brighter colours
• high acuity

Question 24

Describe rods

Answer 24

• blue
• scotopic vision
• black/white vision
• predominant in dim lighting
• high sensitivity
• lack acuity

Question 25

What is spectral sensitivity

Answer 25

sensitive to certain wavelengths of light

Question 26

What is phototopic vision and which type of photoreceptor is it associated with?

Answer 26

- colour vision | - cones

Question 27

What is high acuity?

Answer 27

provide both colour and detail

Question 28

What is scotopic vision?

Answer 28

-black/white vision

Question 29

In which area is there a higher concentration of cones?

Answer 29

fovea

Question 30

What is the fovea?

Answer 30

- area of retina with fewer ganglion cells | - allows for high acuity vision

Question 31

In which areas is there a higher concentration of rods?

Answer 31

outside of the fovea

Question 32

Rods and cones differ in their _____ ratio

Answer 32

convergence

Question 33

What is convergence ratio

Answer 33

ratio of receptors to retinal ganglion cells

Question 34

What does a low convergence ratio result in

Answer 34

high acuity vision

Question 35

Which type of photoreceptor has a low convergence ratio?

Answer 35

cones

Question 36

What does a high convergence ratio result in?

Answer 36

- more sensitive to light - lacks acuity - less precise

Question 37

Which type of photoreceptor has a high convergence ratio?

Answer 37

rods

Question 38

Different levels of acuity and sensitivity between 2 types of photoreceptors is due to differences in _____ and ______

Answer 38

- convergence | - distribution

Question 39

What is rhodopsin

Answer 39

- pigments - G protein linked receptor - responds to light - rather than neurotransmitters

Question 40

Where is rhodospin found?

Answer 40

-in the rods

Question 41

Process of transduction in the dark

Answer 41

- sodium channels remain partially open | - release glutamate

Question 42

What is it called when sodium channels remain partially open?

Answer 42

partial depolarization

Question 43

Process of visual transduction when light strikes

Answer 43

- sodium channels close - rods hyperpolarize - inhibit glutamate release

Question 44

What is the result of the release of biopolar cells from inhibition

Answer 44

activation

Question 45

What is strange about the configuration of retinal cell layers?

Answer 45

faces backwards

Question 46

2 problems with the configuration of retinal cell layers

Answer 46

- incoming light distorted by other cell layers before reaching photoreceptors - there is blind spot

Question 47

what is the fovea

Answer 47

- area of retina | - with fewer ganglion cells

Question 48

what is the result of the fewer amount of ganglion cells in the fovea?

Answer 48

high acuity vision

Question 49

How can we have clear and detailed vision?

Answer 49

eye movements put objects of interest on fovea

Question 50

What is another name for eye movements

Answer 50

saccades

Question 51

What would happen without saccades?

Answer 51

visual images would disappear

Question 52

What is perceptual completion?

Answer 52

optical illusion in which color, boundary or light is seen where it doesn't exist

Question 53

describe the concept of temporal integration

Answer 53

- our perception is the sum of input | - received during last few fixations