Location in the Visual World

Question 1

region of the visual world that is seen by ones eyes

-

Answer 1

visual field

Question 2

info in the left visual field goes to what hemisphere?

Answer 2

right

Question 3

each __ responds to a stimulation on just a small circular patch of the retina- the cells receptive field

Answer 3

retinal ganglion cell

Question 4

Light falling on one place on the retina will activate one ganglion cell, and light falling on another place will activate a different ganglion cell
-this is?

Answer 4

coding location

Question 5

cells in the ___ also have a visual field

Answer 5

lateral geniculate nucleus

Question 6

each LGN cell represents?

Answer 6

a particular place

Question 7

receptive fields of cells in the cortex are typically _____ than those of the retinal ganglion cells

Answer 7

larger

Question 8

is more cortical tissue devoted to cells in the fovea or in the periphery

Answer 8

the fovea

Question 9

the ore information that is being sent along a pathway, the more?

Answer 9

cortical tissue is devoted to it

Question 10

where are the central and periphery visual fields represented in V1

Answer 10

central part of visual field= posteriorly

periphery= anterior

Question 11

the upper part of the visual field is represented where in V1? and the lower part?

Answer 11

• upper part= bottom of V1

- bottom part= upper V1

Question 12

what is the best in the central part of the visual field?

Answer 12

acuity (from cones)

Question 13

what has a larger receptive field: retinal ganglion cells or cells in the cortex

Answer 13

cortex cells

Question 14

the receptive field of a corticol neuron must be composed of ?

Answer 14

the receptive field of many RGCs

Question 15

what brain structures are almost all connected by corpus callosum and what ones are not connected

Answer 15

most of the frontal lobes are connect to each other and the occipital lobe has NO callosal connections

Question 16

what is the one exception to the occipital lobe having no callosal connection

Answer 16

cells that lie along the midline of the visual field are connected to one another via the corpus callosum to that their receptive fields overlap

Question 17

cells response to a particular stimulus is?

Answer 17

selective

Question 18

place a straight line positioned at 45 degrees angle in front of the eyes is how we see?

Answer 18

shape

Question 19

retinal ganglion cells only respond to?

Answer 19

absence of light, not to shape

Question 20

concentric circle arrangement of retinal ganglion cells

Answer 20

look this up

Question 21

RGC have on center cells so they are excited when?

and inhibited when?

Answer 21

light falls on the center portion of the receptive field
- inhibited when light falls on the periphery of the receptive field
(concentric circle arrangement)

Question 22

if light crosses the whole receptive field of a RGC on center cell there is?

Answer 22

weak excitation

Question 23

RGCs have off center cells so these are excited when? and inhibited when?

Answer 23

= excited when light falls on the periphery of the receptive field and
- inhibited when light falls in the center of receptive field

Question 24

light across the whole receptive field of a off center cell produces

Answer 24

weak inhibition

Question 25

what tells the brain about the amount of light hitting a certain spot on the retina compared with the rest or the retina

Answer 25

each retinal ganglion cell

Question 26

neighboring retinal ganglion cells recieve there inputs from?

Answer 26

an overlapping set of photoreceptors b/c there receptive field overlap

Question 27

a small spot of light shining on the retina is likely to produce activity in off center or on center cells

Answer 27

both

Question 28

the amount of light reflected by an object relative to its surroundings

Answer 28

luminance contrast

Question 29

luminance contrast allows for?

Answer 29

input from the RGCs to tell the brain about shape

Question 30

V1 neurons receive in put from multiple? and have much larger receptive fields than them

Answer 30

RGCs

Question 31

how do cells behave like orientation detectors

Answer 31

excited by bars of light orientated in particular directions

Question 32

simple cells have a receptive field with a ?

Answer 32

rectangular on-off arrangement

Question 33

simple cells either prefer __ or ___?

Answer 33

horizontal orientation or oblique (slanted) orientation

Question 34

maximally excited by bars of light moving on a particular direction through the receptive field

Answer 34

complex cells

Question 35

maximally responsive to moving bars, also have a strong inhibitory area at one end of the receptive field

Answer 35

hypercomplex cells

Question 36

hypercomplex cells help detect

Answer 36

edge detection and motion

Question 37

neurons are organized into functional columns (0.5 mm strip or cortex) - -> columns comprise of neurons with similar? - -> inputs arrive in layer ___, and then connect ___ with other layers

Answer 37

- functions | - layer 4, vertically

Question 38

ocular dominance columns recieve input from ?

Answer 38

left or right eye

Question 39

adjacent columns house neruons that are responsive to slightly different?

Answer 39

orientations, forming an array of 180 degrees

Question 40

every neuron in the same column has?

Answer 40

the same orientation bias (ex 45 degrees)

Question 41

in temporal cortex, cells are maximally excited by complex visual stimuli - examples?

Answer 41

May be selective to particular faces seen head on, to faces viewed in profile, to the posture of the head, even to certain facial expressions

Question 42

recognizing that na object is the same across different viewing orientations

Answer 42

stimulus equivalence

Question 43

what is necessary for activation of most neurons on the temporal lobe?

Answer 43

complex features

Question 44

complex features that are necessary for activation of temporal lobe neurons include?

Answer 44

size colour texture orientation

Question 45

neurons in Temporal coretx that have similar bot not identical responsiveness to particular features cluster where in accordance with each other? How does this happen?

Answer 45

cluster in columns - -> experience! to tell it what is related and what is not - -> harder to tell differences between shapes you have not seen

Question 46

the preferred stimulus of neurons in the temporal lobe are able to alter their preference with?

Answer 46

experience

Question 47

obtains entire range of colours in visual world by mixing 3 colours

Answer 47

subtractive colour mixing

Question 48

subtractive colour mixing is property of the ?

Answer 48

cones in the retina

Question 49

increases light to make colour

Answer 49

additive color mixing

Question 50

the lighter the colour , the more ___ it contains

Answer 50

light

Question 51

why does a white surface reflects entire visible spectrum

Answer 51

because the lighter the colour the more light it contains

Question 52

Explanation of color vision based on the coding of three primary colors, red, green, and blue

Answer 52

trichomatic theory

Question 53

the colour we see is determined by the relative responses of

Answer 53

different cone types

Question 54

what are the 4 basic colours

Answer 54

red green yellow blue

Question 55

what can explain colour blindness

Answer 55

trichomatic theory | - some ppl are born without cones for a specific colour

Question 56

can the trichomatic theory explain afterimages? (red-green; blue-yellow)

Answer 56

no

Question 57

Explanation of color vision that emphasizes the importance of the opposition of colors

Answer 57

opponent process theory

Question 58

in the oppon process theory what colour oppose each other

Answer 58

- red- green | - blue - yellow

Question 59

where does opponent processing occur? | - what kind of receptive fields

Answer 59

in about 60% retinal ganglion cells | --> on and off center surround receptive fields

Question 60

explain the opponent color contrast response with respect to receptive fields

Answer 60

- center of receptive field in excitatory to some colours and inhibitory to other colours - stimulation to the periphery has the opposite effect (center is responsive to one wave length and the surround the other)

Question 61

colour sensitive cells are found in ___ in V1 which also respond in a _____ manner

Answer 61

- blobs | - opponent process manner

Question 62

neurons in V1 respond to wavelength of colour whereas neurons in V4 respond to?

Answer 62

- various perceived colours | _ center is excited by a certain colour and the surround in inhibited)

Question 63

what may be important for colour constancy and why

Answer 63

neurons in corticol region V4, b/c perceived colour is constant relative to other colours regardless of the change in illumination

Question 64

involved in processing visual info for action

Answer 64

dorsal steam

Question 65

Neurons in this area are silent to visual stimulation when a person is under anesthesia

Answer 65

dorsal stream

Question 66

Some cells in this area process the visual appearance of an object to be grasped

Answer 66

``` dorsal stream ( fire even when watching other pick up object) ```

Question 67

Destruction of the retina or optic nerve of one eye, producing loss of sight in that eye

Answer 67

monocular blindness

Question 68

Blindness of an entire left or right visual field

Answer 68

homonymous hemianopia

Question 69

Blindness of one quadrant of the visual field

Answer 69

quadrantanopia

Question 70

Small blind spot in the visual field caused by a small lesion or migraines of the visual cortex

Answer 70

scotoma

Question 71

damage to the visual stream causes what? (3)

Answer 71

- visual form agnosia: can recognize objects or drawing of objects - color agnosia (achromatopsia) - face agnosia (propagnosia)

Question 72

copy objects and even draw objects from memory. However, they cannot later recognize these copied objects. – still appropriately shape their hands when grasping for objects, despite not being able to recognize those object

Answer 72

visual form agnosia, damage to ventral stream

Question 73

correct grasp of object due to

Answer 73

ventral stream

Question 74

injury to dorsal stream =

Answer 74

optic ataxia: defecit to visual control of reaching and other movements