Brainscape's Knowledge GenomeTM

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


See full index

Perception Block 12 > Extrastriate Processing > Flashcards

Extrastriate Processing Flashcards

1
Q

Visual info that occurs in the retina, LGN, and striate cortex undergo further analysis and synthesis in visual areas outside the striate cortex referred to as

A

Extrastriate cortex

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

Extrastriate cortex

A
  • 20 different distinct visual areas
  • each area contains retinotopic map, a map of the visual field
  • each area (specialized modules) plays a different role in processing visual information
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Map of the visual field in the 20 visual areas of the extrastriate

A

Retinotopic map

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

Widespread distribution of information beyond striate cortex

A

Projections to various extrastriate cortical areas

  • these in turn projecto to numerous higher level cortical centers
  • synthesized info from the different senses, integrating it with memory

Feed forward

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

Feed back info in the extrastriate cortex

A

From higher cortical areas to lower areas including hire striate cortex
Via reciprocal connections

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

Central stream

A

What pathway

-ID objects

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

Dorsal stream

A

Where
Motion perception
Localization in visual space
Action organization

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

Dorsal stream components

A

Dorsal-dorsal stream

  • processes action information
  • damage two this area may result in optic ataxia
  • inability to point to or reach for a visual target

Central-dorsal stream
-includes extrastriate area MT/V5

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

Cortical streams as extension of the retinogeniculate pathways

A
  • the parvo pathway does have input to the ventral processing stream
  • magno pathway inputs to the dorsal stream
  • both retinogenicualte pathways may provide input to both cortical processing streams
  • they communicate with each other
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Higher visual areas and modules

A

Analyze specific attributes of the visual world

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

Area 4 (V4)

A

Abundance of cells withchromatic sensitivities

  • makes this area well adapted to color perception
  • color
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cells in the inferotemporal cortex (IT)

A

Respond to complex forms, including faces

-indicates a role in form perception

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

These are considered to be part of the ventral processing stream

A

V4 and IT

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

Cells in area MT/V5 are well suited for

A

Encoding motion

-dorsal processing stream

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

PET

A

Radioactive tracer used to observe changes in blood flow, indicative of increases cortical metabolism

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

MRI

A

Better resolution than PET
Reveals corticala activity by detecting levels of oxygenation
-BOLD;blood oxygen level dependent

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

Use of MRI and PET scan in brain

A

Used to monitor brain activity while a subject performs a task, such as looking at a moving object

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

Imaging studies reveal the task determines chip area of the brain

A

Is most active

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

If a human subject views an array of various colored, moving objects and is asked to attend to a green object

A

Areas in the ventral stream may show elevated activity

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

If the shape (or form) of the object becomes the focus of attention the ventral stream may again show activity . The subject no views the same array but asked to attend to the movement of the objects

A

Dorsal stream may manifest increased activity

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

Binding problem

A

-to perceive a red car moving down highway
-motio nand position info processed along he dorsal
-color and form information processed along the ventral stream
-information from these two streams is combined with memory
-information form the various cortical areas must be synthesized to result in an integrated perception
-

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

Binding problem coordinated by

A

The prefrontal cortex

-this area has long been though to play a role in cognition

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

Cells in _______ are capable of analyzing motion information

A

MT-V5

  • the aperture problem
  • this stimulus, which is perceived as a plaid moving in the direction indicated, is composed of two drifting gratings as illustrated
  • whereas each of the two component drifting grating would appear to move in the direction indicated, the plaid (an integrated stimulus composed of two components) appears as a single object moving in an aintermediate direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Selective neurons in extracellular recordings

A

Respond strongly to the movement of the individual grating components of the plaid

Respond weakly to the movement of the plaid itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Certain cells in the areas MT/V5 respond best tp the

A

Movement of the plaid as a whole

-these neurons encode what we perceive rather than the individual grating components

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

Global motion perception in area MT/V5 can be demonstrated with

A

Dot kinematograms
-extracellular recordings show that certain neurons constituting this region manifest coherence thresholds very similar to those measured psychophysically in the same animal

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

Human PET and fMRI studies of random dot kinematograms and areas MT/V5

A

It is more active when a human subject views a moving object than when viewing a stationary object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Motion after effect

A

Motion illusion that occurs in the absence of motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Waterfall illusion MAE

A
  • induced by staring at downward rushing water for several minutes
  • when gaze is changes from the waterfall to the surruonding landscape, the landscape appears to rise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Result from the adaptation of direction-specific motion detectors

A

MAEs

  • is adapting stimulus reduces sensitivity to its direction of movement
  • causes subsequently viewed stationary stimuli to appear to move in the opposite direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Motion detectors mediating MAE are suspected to be located in the

A

Cortex

  • first site of substantial interaction between the two eyes
  • adaptation of one eye elicits an MAE in the other eye
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Human viewing concentric rings moving outward and suddenly stop

A
  • moving rings activate Mt/V5
  • when stopped, individual Eilene experience an MAE
  • stationary rings appear to move inward
  • fMRI shows that MT/V5 is active even though rings are no longer moving
  • provides additional evidence for MT/V5 role in motion perception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

The receptive fields of cells in IT

A

Large

  • provides the basis to integrate information over an extensive area and analyze complex patterns
  • cells in IT respond best to comparatively sophisticated shapes
  • compared to cells ins trade cortex, which respond to bars, edges, and gratings
34
Q

Mikey cortex is called IT probably equivalent to the lateral occipital complex in humans
-responds well to

A

Objects, but not to scrambled objects

-LOC responds to all objects, not showing selectivity for a particular type of object

35
Q

FFA (fusiform face area)

A

Responds well to faces but not other objects

36
Q

PPA (parahippocampal place area)

A

Strongly activate by objects and places, but not by faces

0percieving senses

37
Q

Prospagnosia

A

Inability to recognize faces

  • FFA and V4 are close to each other
  • may also manifest cerebral achromatopisa
  • inability to distinguish hues
38
Q

Top-down attention

A

Endogenous attention

  • volitional, you do not need to attend to these words, and could choose to turn tour attention elsewhere
  • choosing to study pages of a book with other stimuli around you
39
Q

Bottom up (Exogenous) attention

A

Studying and a loud crashing sound causes you to look up

40
Q

Attention as a spotlight

A
  • Directed toward the object of interest

- when first go into coffee shop, its broad and then narrrwos as you look for seat

41
Q

Most of the time, the spotlight of attention is directed at the same object the ______

A

Eyes are fixating

  • an object that has captured ones attends ncan usually best be investigated using fovea vision
  • the spotlight of attention does not need to coincide with fixation
  • the ability to fixate one object but attend to another has been demonstrated both for top down and bottom up attention
42
Q

Serial processing during visual attention

A

Looking at all of the tables in the coffee shop to find an empty one
-we direct our spotlight of attention on each object of interest to see if its available

43
Q

Preattentive processing

A

If there is a color assigned to empty tables, you would be Abel to find an empty table much quickly
-number of unavailable tables and distractions do not matter in this case

44
Q

Change blindness

A

When looking at two pictures that have very subtle differences simultaneously, it is hard to see the changes between the two.
-phenomenon in which we cannot readily see the differences between the two images

45
Q

How to fix change blindness

A

Rapidly change between the two pictures

46
Q

Red/green bar activity: monkey fixating on X, make him respond to red in peripheral

A

Neuron repsonsds vigorously

47
Q

Monkeys responds to green

A

Response to red is diminished

48
Q

Top down visual attention is where

A

Prefrontal cortex

49
Q

Top down attention and neuronal activity

A

Cells in striate cortex apparently do not demonstrate top down attentional influences

  • suggests there may be a filtering of visual information from striate cortex V4
  • at least partially dependent on the stimulus to which the animal is attending
50
Q

Lesions in striate cortex

A

Simple blind spots (simple scotoma)

51
Q

Lesions in extrastriate areas

A

Visual agnosoia

  • inability to recognize objects
  • this condition can take many different forms depending on the area off the brain compromised
52
Q

Object agnosia

A

Can’t recognize objects

53
Q

Agnosia for drawings

A

Can’t recognize drawn objects

54
Q

Prosopagnosia

A

Can’t recognize faces

55
Q

Simultagnosia

A

Can’t perceive more than one object

56
Q

Color agnosia

A

Can’t association of Colton’s with objects

57
Q

Color anomia

A

Can’t name Colton

58
Q

Cerebral chtomatopsia

A

Can’t distinguish hues

59
Q

Visual spatial agnosia

A

Stereoscopic vision, topographical relations

60
Q

Cerebral akinetopsia

A

Motion perception problems

61
Q

Defect in the perception of motion

A

Akinetipisa

62
Q

Damage to the dorsal processing stream

A

Akinetopsia

63
Q

What is normal in someone with akinetopsia

A

VF, VA, and color vision

64
Q

Cones in someone with achtomatopsia

A

Normal complement of cones, but is unable to distinguish hies secondary to an extrastriate lesion

65
Q

Patient experience with cerebral achromatopsia

A
  • experiences color vision prior to the lesion
  • loss of color is quite stark
  • visual world is seen as black and white
  • this is unlike the cone-based color anomalies where patients have impaired color discrimination but claim to see color
66
Q

Certain lesions can lead to visual neglec: synthesthesia

A

Patient with this condition mayshave only the left side of the face and ignore the right side
-lesions in the superior temporal lobe

67
Q

Simultagnosia

A
  • may not be able to perceive more than one object at a time
  • may be present in Balint’s syndrome
  • bilateral damage to the parietal lobes
68
Q

Balint’s syndrome

A

Condition in which there is typically bilateral damage tot he parietal lobes
-simultagnosia

69
Q

The presentation of a letter or number results in the perception of a color

A

Synesthesia

  • the patient may report the perception of green whenever presented with the number 6 and red presented with 2.
  • 5+1=green
70
Q

Charles bonnet syndrome

A

Visual phantom

  • 15% of visually impaired patients
  • complex hallucinations that take a form of a person
  • very vivid
  • patients most likely to experience it hours to days following visual loss
  • recognized by the patients by not being real
  • this is how it differs from schizo or Dementia
  • most patients not bothered by the hallucinations
71
Q

Phantom vision is thought to result from the loss f

A

Normal affront input to the visual cortex
-may explain the relatively high incidence of CBS in patients with ARMD, wherein the major representation to striate cortex is destroyed

72
Q

The content of the visual hallucinations usually do not disturb CBS patients, however

A

They may be concerned they have something more serious neuro going on

73
Q

Grandmother cell?

A
  • Not confined to higher cortical areas
  • occurs in the lower centers including the striate cortex too
  • the visualization of a remembered object results in a pattern of activity similar to that elicited by actually viewing object
  • hippocampus encoding memories
74
Q

Perceptual learning

A

Psychophysical studies reveal the visual performance of adults can be improved with practice

  • stereoscopic
  • orientation
  • peripheral reading speed
  • and vernier tasks
75
Q

Learning of certain tasks appear to be

A

Selective

-suggest is neural learning occurs early in the visual system

76
Q

Does A person need to be aware they are learning for vision to be trained?

A

No

77
Q

Necker cube

A

Ambiguous or bistable figure

-looks like its going in or out of the page depending on your perspective

78
Q

Cortex manifests a significant degree of

A

Specialization

79
Q

Central processing stream areas,, including

A

V4 and IT

  • object recogniztion
  • what
80
Q

Dorsal stream

A

MT/V5

  • spatial
  • where
81
Q

Prefrontal cortex

A

Coordinate info from the ventral and dorsal

Perception Block 12 (6 decks)

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