Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Sensation and perception > lecture 2 > Flashcards

lecture 2 Flashcards

1
Q

what is the distal stimulus for vision

A

light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

physiological representation of wavelength

A

colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

physiological representation of intensity

A

brightness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

physical properties of light

A

wavelength, intensity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is light

A

form of electromagnetic energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

visible spectrum wavelength range

A

~400-700nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where are receptors located in the eye

A

in the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

function of the eye

A

to focus image onto the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

proximal stimulus representing light

A

retinal image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

role of the iris an pupil

How does it achieve this?

A

limit the amount of light passing through
has an adjustable aperture
allows us to deal with a great range of light intensities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the diameter range for the pupil

A

2-9mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

role of the cornea and lens

A

to focus light onto the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how much focusing power does the cornea have?

A

80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how much focusing power does the lens have?

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how can the lens change shape?

A

due to the actions of the ciliary muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what shape is the lens when focusing a close object

A

it becomes fatter and shorter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what shape is the lens when focusing far objects

A

thinner and longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

myopia

A

near sightedness

light focused in front of the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

hyperopia

A

far-sightedness

light focussed behind the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how to correct myopia

A

concave lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how to correct hyperopia

A

convex lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

retina

A

photosensitive layer at the back of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

role of retina

A

carry out transduction, transform light into electrical impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

cells in the eye from front to back

A 
photoreceptors
(horizontal cells) 
bipolar cells 
(amacrine cells) 
retinal ganglion cells 
optic nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what must light pass through to reach photoreceptors?

A

blood vessels, cells and axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

where are receptors?

A

layer furthest from incoming light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how does transduction occur in the eye?

A

visual photopigments reacting to light and triggering electrical signals

28
Q

what is the action of a change in the shape of the lens called?

A

accommodation

29
Q

how many rods are there?

A

120 million

30
Q

when are rods most useful?

A

most useful at night, useless during the day

31
Q

what type of vision do rods produce?

A

monochromatic

32
Q

how sensitive are rods?

A

very sensitive

33
Q

what light do rods respond well to?

A

dim light

34
Q

how many types of rods are there?

A

one

35
Q

what wavelength do rods respond best to?

A

medium wavelengths (green light)

36
Q

what is the purkinje shift

A

at night red looms darker than green

37
Q

what causes the purkinje shift?

A

rods respond to green light

38
Q

how many cones in the human eye?

A

6 million

39
Q

are cones more or less sensitive than rods?

A

less sensitive

40
Q

when do cones ework best?

A

work best during the day, useless at night

41
Q

what are cones responsible for?

A

colour vision

42
Q

how many types of cones are there? what are they?

A

three types: red, green, blue

43
Q

what wavelength do red cones respond best to?

A

long wavelengths

44
Q

what wavelength do green cones respond best to?

A

medium wavelengths

45
Q

what wavelength do blue cones respond best to?

A

short wavelengths

46
Q

what receptors are active during scotopic vison?

A

only rods

47
Q

what receptors are active during photopic vision

A

only cones

48
Q

what receptors are active during mesopic vision?

A

both rods and cones are active?

49
Q

what light intensities/ times of day does mesopic vision cover?

A

full moon/ bright moonlight to early twilight

50
Q

what effect doe bright light have on photoreceptors?

A

bleaches photopigments causing them to stop responding

51
Q

what is dark adaption?

A

increase in eyes sensitivity in the dark

52
Q

how many times greater is eyes sensitivity after 20-30 minutes in the dark?

A

approximately 100,000 times greater than sensitivity in the light

53
Q

what photoreceptors are concentrated on the fovea?

A

cones

54
Q

convergence

A

one neuron receives signals from many other neurons

55
Q

what receptors does the peripheral contain?

A

a large amount of rods

a small amount of cones

56
Q

what is the blind spot

A

an area on the retina that contains no rods and no cones

57
Q

convergence of rod cells

A

120 rod cells to 1 ganglion cell

58
Q

convergence of cone cells

A

6 cone cells to 1 ganglion cell

59
Q

acuity

A

the ability to detect fine details of a stimulus

60
Q

high acuity

A

can detect fine details

61
Q

low acuity

A

can detect only course details

62
Q

do rods or cones have a higher acuity? why?

A

cones have a higher acuity due to less convergence

63
Q

where is the highest acuity in the retina?

A

the fovea

64
Q

where does acuity decrease?

A

toward the peripheral/ away from the fovea

in low lighting conditions (scotopic)

65
Q

what ensures fovea is focussed on the fovea/ high acuity?

A

eye movements

Sensation and perception (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions