Exam 3 Flashcards
chapters 6-8 (128 cards)
1
Q
what is the What pathway?
A
The ventral stream
2
Q
What does the ventral visual processing stream consist of?
A
Areas of the occipitotemporal and temporal regions that are devoted to the processing visual stimuli
3
Q
Cells is the ventral visual system (what pathway) fire in response to what?
A
Relatively simple stimuli, but cells further along the stream fire to more complex, specific stimuli
4
Q
what falls under the category of “simple stimuli” in the ventral visual system?
A
Orientation to lines and edges, color, shape, etc.
5
Q
What falls under the category of “complex stimuli’ in the ventral visual system?
A
Faces and whole objects
6
Q
what are the two trends noted in the ventral visual system?
A
1) cells early in the pathway fire to simple stimuli, and cells farther along in the pathway fire to complex stimuli
2) receptive fields become larger
7
Q
What type of receptive field allows for the cell to respond to objects on he basis of their global shape (allows an object to be identified regardless of its size or where it is located in space)
A
large receptive field
8
Q
what is the consequence of having a large receptive field?
A
Some information about an item’s position in space is lost
9
Q
what does area V4 process?
A
Color processing as well as colors in different hues or lighting
10
Q
Cells in the ventral processing stream are
often sensitive to _____, which aids object
recognition.
A
Color
11
Q
damage in the ventral stream of the cortex leads to a deficit in…
A
Object recognition
12
Q
Visual Agnosia definition
A
An inability to recognize objects in the visual modality that cannot be explained by other causes
13
Q
True or false: Visual agnosia is modality specific
A
Yes! This mean that it manifests in only one of the senses (in this case, the visual sense)
14
Q
What are the two types of visual agnosia?
A
Apperceptive and associative
15
Q
Apperceptive agnoisa
A
- is a fundamental difficulty in forming a perception
-the data cannot be bound together to allow the person to to perceive a meaningful whole
16
Q
Associative agnoisa
A
Basic visual information can be integrated to form a meaningful perceptive whole, but that particular whole cannot be linked to stored knowledge
17
Q
What is the main difference between Apperceptive and associative agnoisa?
A
the type of visual information that can be processed
- Classic Apperceptive agnoisa can process crude visual information
- People with associative agnoisa can perceive much more detailed info than those with Apperceptive agnosia, which is proven by ther ability to match and copy items, and they can extract some information about general shape
18
Q
Where is brain damage typically seen in patients with Apperceptive agnoisa?
A
Diffuse damage to the occipital lobe and surrounding areas
19
Q
Where is damage typically seen for patients with associative agnoisa?
A
The occipitotemporal regions of both hemispheres and sub-adjacent white matter
20
Q
What is Prosopragnosia?
A
(Agnoisa for faces)
A selective inability to recognize or differentiate faces
21
Q
Where is damage found in prosopagnosia patients?
A
The ventral stream of the right hemisphere
22
Q
where does damage for patients with visual agnosia of words occur?
A
The left hemisphere in the region known as the visual word form area
23
Q
What percent of the population suffers from congenital prosopragnosia?
A
2%
24
Q
What types of information can prosopagnosia patients determine?
A
- that a face is a face
- age
- gender
- facial expression/emotion
25
Category-specific deficit
The inability to recognize or identify a certain category of objects even though the ability to recognize other categories of items in that same modality is retained
26
Sparse coding
The theory that a small but specific group of cells responds to the presence of a given object
27
What is an extreme example of sparse coding? Is it thought to be right?
The grandmother cell theory; no
28
population coding
The theory that the pattern of activity across a large population of cells codes for individual objects
29
What is an extreme version of the idea of Population coding?
That every cell in the ventral stream is involved in coding for every object
30
What is used to study visual invariance?
Adaptation
31
Inversion effect
Phenomenon in which recognition is poorer when an object is turned upside down. Suggests that faces are processed as wholes, configurally
32
Conjunctive encoding
Assumes that features are explicitly conjoined, or linked together
33
Nonlocal binding
Assumes that a whole object is represented simply by the co-activation of units that represent the parts of the objet in particular locations
34
what are the two possible models of how individual features combined into whole shapes?
Conjunctive encoding and nonlocal binding
35
Fusiform face area (FFA)
Which exhibits a greater response to faces than to other objects
36
Parahippocampal place area (PPA)
Appears to process visual information related to placed in the local environment
37
Extrastriate body area (EBA)
Responds preferentially to images of human bodies and body parts, compared to various inanimate objects and object parts
38
What have researchers discovered about monkey face-specific cells?
They are distributed asymmetrically and are more evident in the right hemisphere
39
Double dissociation
A method for demonstrating that two mental processes can proceed independently of one another, and that they rely on different neural substrates
40
What did evidence from brain-damaged individuals, neuroimaging, and electrophysiology indicate that _____ are processed differently than other classes of objects
Faces
41
Which hemisphere plays a predominant role in face processing?
Right
42
What is the Superior Temporal Sulcus (STS) involved in processing?
Those features of the face that change, such as eye gaze and expression
43
Where is the Parahippocampal place area (PPA) located?
In a ventral cortical region bordering the hippocampus
44
What does the PPA typically respond to?
Strongly to visual scenes such as landscapes, rooms, houses, or streets
45
The ventral stream region in the left hemisphere appears to be responsive to visually presented _______.
Words
46
Multi-voxel pattern analysis
To examine the degree of activation in certain brain regions, as well as the pattern or mosaic of activation
47
the more similar visual items are, the more similar are their ______ of activity across the brain
Patterns
48
auditory agnosia
The inability to recognize sound
49
auditory agnosia usually manifests in one of three ways. What are these three ways?
- Verbal auditory agnosia
- Nonverbal auditory agnoisa
- Mixed auditory agnoisa
50
What is Verbal auditory agnoisa?
also known as Pure-word deafness
Words cannot be understood, although the ability to attach meaning to nonverbal sounds in intact.
Often complains that speech sounds like “an undifferentiated continuous humming noise without any rhythm”
51
nonverbal auditory agnoisa
Rarer than verbal auditory agnosia
The ability to attach meaning to a word in intact, but the ability to do so for nonverbal sounds is disrupted
Ex: cannot categorize a dog bark or a lawn mower
52
Mixed auditory agnoisa
the ability to attach meaning to both verbal and nonverbal sounds is affected, although the patients can determine whether two sounds are identical or different and whether one sound is louder than the other
53
Somatosensory/Tactile agnoisa
A condition in which a person is unable to recognize an item by touch
54
What are the two types of somatosensory agnosia that have been proposed?
1) he affected person has the inability to use tactile information to create a percept
2) the percept is more or less intact but cannot be associated with meaning (tactile asymbolia)
55
What is tactile asymbolia
The tactile information cannot be linked to its symbolic meaning
56
In everyday life, we often receive _________ cues to recognition simultaneously from multiple modalities
Parallel
57
What region is known to be important to the visual perception of objects?
lateral occipital complex (LOC)
58
Voices of familiar people have been shown to activate which brain area more than the voices of unfamiliar people?
FFA
59
What stream is the dorsal pathway?
The “where”
60
the dorsal visual processing stream projects from where to where?
primary visual areas to parietal regions
61
What is another name for the Primary somatosensory area?
the Anterior Parietal cortex
62
which lobe is primarily concerned with somatosensory representations?
the anterior parietal lobe
63
Which cortex is multisensory and is crucial in many aspects of spatial cognition?
the posterior parietal cortex (PPC)
64
what are the superior parietal lobule and the inferior parietal lobule separated by?
the intraparietal sulcus
65
Area MT(middle temporal V5) and MST (he medial superior temporal area) contribute to the understanding of what?
motion
66
the primary visual cortex and the somatosensory cortex provide information about what?
the body in space
67
What part of Einstein's brain was larger and attributed to his increased ability to do math and physics?
the parietal cortex
68
What are the functions of the three separate pathways that project from the dorsal stream to other areas?
1. spatial working memory
2. visually guided action
3. Spatial navigation
69
What is the pathway that is concerned with supporting spatial working memory?
connects the parietal cortex to the prefrontal cortex
70
What pathway is concerned with supporting visually guided actions such as reaching and grasping?
connects the parietal cortex to the premotor cortex
71
What pathway is concerned with supporting spatial navigation, such as wayfinding around an environment?
connected the parietal cortex to the medial temporal cortex (including hippocampus and parahippocampal cortex)
72
why are cells in the parietal areas not good at detecting the visual properties of objects?
because they are not sensitive to form or color
73
Cells in the posterior parietal cortex appear to be responsive to a combination of the retinal location of the visual stimulus AND the position of the animal's eyes or head. This allows the creation of what in the brain?
A stable spatial map of the world
74
In patients with parietal damage, is it more difficult for them to determine if an object is facing right or left or is it more difficult to distinguish up or down?
it is harder for them to distinguish left facing from right facing
they are good at up/down distinction, as well as if an object is presented at different angles
75
which plane does depth perception help us localize items in?
near-far plane
76
Binocular Disparity
discrepancy between the images seen by two eyes that is a cue to depth
77
Cells in which cortex are sensitive to different amounts of binocular disparity?
primary visual cortex
78
what two cue types are integrated in area MT to code for depth?
binocular disparity and motion parallax
79
Is motion parallax a binocular or monocular depth cue?
monocular
80
what is the gist of motion parallax?
near objects move slower and farther objects move faster
81
egocentric reference frames
specify an object's location in relation to some aspect of the self
82
Allocentric reference frame
specify an object's location in relation to other objects
83
Damage to which parietal lobe is most often associated with egocentric neglect?
right parietal lobe
84
Object-centered neglect
patient ignores half of an object regardless of how that object is displayed or oriented
85
What are the names of the three different realms?
- Personal space
- Peripersonal space
- Extrapersonal space
86
Personal space
referring to spatial position on the body
87
Peripersonal space
referring to the spatial realm within arm's reach, or near space
88
Extrapersonal space
far space, referring to the area beyond arm's reach
89
Categorical spatial relations
specify the position of one location relative to another in dichotomous categorical terms (above vs below, top vs bottom, left vs right)
90
Coordinate (or metric) spatial relations
specify the distance between two locations
91
which hemisphere is specialized for determining categorical spatial relations?
left
92
which hemisphere is specialized for computing coordinate (metric) spatial relationships?
right
93
corollary discharge
a signal to visual areas about the upcoming eye movements
94
What is one important function of the dorsal stream?
to participate in sensory-motor translation-transforming sensory representations into action patterns
95
Constructional praxis
the ability to motorically produce or manipulate items so that they have a particular spatial relationship
96
What is a critical element of constructional praxis?
spatial perception
97
Optic ataxia
a type of spatial deficit seen in patients with parietal lobe damage. these patients have difficulty with visually guided reaching and may fail to take obstacles into account when reaching for an object
98
true or false: optic ataxia appears to be doubly dissociable from visual agnosia.
true
99
which stream is important in supporting both visually guided reaching and grasping movements?
the dorsal stream
100
Egocentric disorientation
the inability to represent the location of objects in relationship to the self
101
landmark agnosia
is more like an object-recognition deficit than a true spatial deficit, although it does disrupt wayfinding ability
102
anterograde disorientation
a patient is unable to construct new representations of environments due to parahippocampal damage
103
heading disorientation
a patient is unable to recognize landmarks and understand relations between locations in space due to retrosplenial cortex damage
(has trouble knowing his own orientation in a familiar or unfamiliar environment)
104
Which hemisphere plays a leading role in speech production (at least for right-handers)?
the left
105
Aphasia
a disruption in the ability to process or produce language
106
Wada technique almost always leads to speech arrest after injection into which hemisphere?
left
107
in split-brain patients, only the left hemisphere can do what?
produce speech output
108
Broca's aphasia
damage to this region results in a difficulty with speech output, but can comprehend just fine
109
what does lesioning anterior to the central fissure cause?
Broca's aphasia
110
Wernicke's aphasia
characterized by disrupted speech comprehension, but speech output is fluent
111
What are the words of patients with Wernicke's aphasia called?
Word salad
112
semantic paraphasia
substitute a word with a similar meaning to the intended word
113
phonemic paraphasia
substitute a word with a similar sound to the intended word
114
neologisms
made-up words that follow the rules for combining sounds in the language, yet are not real words
115
paraphasias
an inability to link sound images to meaning
116
Anterior regions of the left hemisphere are specialized for ____ _____
speech output
117
Posterior regions of the left hemisphere are specialized for ____ __________
speech comprehension
118
conduction aphasia
the inability to repeat what was just heard (although language comprehension and speech production are intact)
119
Damage to which white matter tract causes conduction aphasia?
the arcuate fasciculus
120
global aphasia
the inability to comprehend or produce language
121
What is the classic three-part model of 19th century aphasiologists/(Classical Neurological Perspective)
1. language input center
2. language output center
3. a critical neural pathway connecting the two
122
What three parts do psycholinguists divide language into?
1. phonology (rules of sound combination)
2. syntax (rules of grammar)
3. semantics (meaning of language)
123
Phoneme
considered the smallest unit of sound that can signal meaning
124
Phonology in Broca's aphasia
may have difficulty producing both the correct phonetic and phonemic representations of speech sounds
125
Phonology in Wernicke's aphasia
may have difficulty producing the correct phoneme (meaning), but do not have phonetic issues (sound)
126
What is N400?
- it occurs about 400ms after the event occurs
- found in the posterior cortex (left temporal cortex)
- it is sensitive to Semantic anomalies
127
what is P600?
- it occurs about 600ms after the event occurs
- it is in bot the posterior and anterior cortices
- it is sensitive to Syntactic anomalies
128
