Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Neuroscience > Vision > Flashcards

Vision Flashcards

(55 cards)

Start Studying
1
Q

photons

A

particles of energy

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

waves

A

electromagnetic energy

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

wavelength

A

colour

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

intensity

A

brightness

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

what controls the lense?

A

ciliary muscles

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

what controls the amount of light hitting the retina?

A

irises

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

where does the light enter through the eye?

A

pupil

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

adjustment of pupil disparity

A

difference between sensitivity and acuity

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

more light =

A

small pupil (reducing light - contraction) = depth of focus (higher acuity as light is focused on retina)

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

less light =

A

dilated pupil (allowing more light - relaxation) = less focus (light dispersed on retina - lower acuity)

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

adjustment of the lense

A

accommodation

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

binocular disparity

A

difference in the position of the same object on the two retinas
constructs 3D images from 2D
greater disparity for closer objects
eyes placed side by side on head

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

5 layers of the retina

A 
retinal gangloin cells
amacrine cells (H - horizontal)
bipolar cells 
horizontal cells (H)
receptors (rods and cones)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what problems does light exiting through the gangloin cells create?

A

blindspot - cant be any receptors where the light exits (retinal gangloin axons exit through the back of the eye)
- completion

distortion - light goes through lots of cells and distorts images
- fovea (high acuity vision)

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

duplexity theory

A

cones and rods mediate different kinds of vision

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

photopic vision

A

cones - used in good lighting and provides high acuity COLOUR vision

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

scotopic vision

A

rods - used in poor lighting when not enough to excite cones

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

what affects how bright a stimulus looks?

A

wavelength

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

Purkinjee effect

A

change in brightness of colours as the amount of light hitting the object is between the two spectral sensitivity curves

GREEN & BLUE brighter under DIM illumination

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

how and why does the eye move?

A

vision is a summation of what we have recently seen
Tremor
Drifts
Saccades (4 per second) - small jerks (visual neurons respond to change)

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

transuction

A

conversion of one energy source to another

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

rhodopsin

A

g protein that responds to light - gets bleached

when in light, sodium channels (as they are partially open in the dark) close and hyperpolarise the rods
- this starts a cascade of intracellular events stopping the release of glutamate

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

retina-geniculate-striate pathways

Study These Flashcards
A

conducts signals from each retina to the primary visual cortex, via the lateral geniculate gyrus

left side of visual field
ipsilaterally (same side) from the temporal hemiretina
or
contralateraly from the inside of the nasal hemiretina which goes across the optic chiasm
then
the pathways go to the lateral geniculate nuclei

24
Q

retinotopic

Study These Flashcards
A

each level of the retina-geniculate-striate pathway is organised like a map of the retina
2 stimuli presented to adjacent areas of the retina excite adjacent neurons at all levels

25
Parvocellular layers
``` (P) top 4 layers of the primary visual cortex small cell bodies responsive to colour fine pattern stationary or slow moving objects ```
26
Magnocellular layers
(M) bottom 2 layers of PVC large cells sensitive to movement
27
match bonds
colour seems less intense next to a darker shade - contrast at edges enhanced
28
contrast enhancement
highlights edges
29
lateral inhibition
receptor on the lighter side of the edges fire more, dull side less - research on the horse shoe crab
30
Hubel and Wiesel (2004) - method
neural understanding of vision microelectrode placed near a single neuron eye movement blocked receptive field of a neuron is identified record response of neuron studies retinal gangloin cells, lateral geniculate neurons, striate neurons from PVC
31
Hubel and Wiesel (2004) - findings
4 commonalities - fovea has smaller receptive field - all neurons had circular receptive fields - all neurons were monocular (receptive fields in one eye but not the other) - some neurons at all levels had receptive fields that had an excitatory and inhibitory area (separated by a circle) on centre cells and off centre cells
32
simple cells
receptive fields that can be divided into off/on regions unresponsive to diffuse light all monocular cortical areas = straight lines can be circles or rectangles
33
complex cortical cells
rectangle receptive fields respond to straight lines different in 3 ways: - larger receptive field - no on/off divide - more binocular complex cells
34
organisation of PVC
functional vertical columns location of columns is influenced by the location on the retina of its visual field neurons with simple preferences synapse onto those with more complex preferences
35
contextual influences
depends on the large scene how visual neurons in the cortex respond
36
hues
colours
37
black
no light
38
grey
intense mixture of wavelengths at low intensities
39
white
intense mixture at high levels
40
trichromats
primates that see in colour (3 cones)
41
dichromats
primates that see in 2 (lack red pigment)
42
component processing (trichromatic theory)
Young 3 different kinds of colour receptors - each with a different spectral sensitivity 3 different cones
43
opponent process theory
Hering 2 different classes of cells for encoding colour and brightness 1) red - hyperpolarisation, green - hypopolarisation 2) blue and yellow - based on the fact that complementary colours cant exist and the after image of one colour is the other
44
visual system
combination of the 2 3 different types of cones (blue, green and red) each has its own absorption spectrum there are cells that respond to one colour and not the other
45
colour constancy
colours stay the same throughout different intensities Edwin Land - Mondrian - colour is determined by an objects reflectance as long as red, green and blue light hit it it will look the same
46
dual opponent colour cells
'on' to one wavelength and 'off' to another concentrated in peglike columns (called blobs)
47
3 types of visual cortex
Primary --> Secondary --> Visual association cortex (top) as you move up the hierarchy the stimuli the cells respond to are more complex and they have larger receptive fields
48
scotoma
damage to areas of the PVC produce areas of blindness in the contralateral visual field
49
perimetry test
test for scotoma
50
hemianscopic
scotoma covering half the eye
51
blindsight
displayed by people with scotomas who respond to stimuli in their area of blindness
52
flow of the visual cortex
SIMPLE ---> COMPLEX
53
dorsal stream
where/control of behaviour - neurons respond to spatial stimuli (movement)/affects direct behavioural interaction with objects what/conscious perception theory - characteristics of objects/mediate the conscious perception of objects
54
prosopagnosia
inability to recognise faces fusiform face area (FFA)
55
akinetopsia
inability to see movement damage to the middle temporal area (MT)

Neuroscience (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions