EXAM 2 Flashcards
1
Q
muscles are composed of
A
muscle fibers
2
Q
muscle fiber contraction is caused by
A
an electrical impulse from a motor neuon
3
Q
where are cell bodies of a motor neuron found
A
ventral portion of the spinal cord
4
Q
motor units are composed
A
a motor neurons and all the muscle fibers it innervates
5
Q
what is a neuromuscular junction
A
a specialized synapse between the nervous system and muscle fibers
6
Q
Function of motor tracts
A
relay messages from the brain to target muscles
7
Q
Lateral Pathway is involved in
A
fine movement of distal limb muscles ( arms, fingers, hands, lower leg, and foot)
8
Q
how do the tracts in lateral pathway differ from the medial pathway
A
in the lateral pathway the tract projects controlaterally
9
Q
how does the lateral pathway project contralaterally
A
crosses from one side of the brain to the opposite side of that body in the medulla
10
Q
medial pathway is involved in
A
control of movements of the trunk and proximal limb muscles (upper arm and thighs)
posture and bilateral movements
11
Q
how does the medial pathway tract differ from the lateral pathway
A
projects both contralaterally and ipsilaterally
12
Q
function of cerebellum
A
coordination of muscle movement and timing
planning of movements
the learning of motor skills
13
Q
what are the three main divisions of the cerebellum
A
vestibulocerebellum
spinocerebellum
cerebrocerebellum
14
Q
areas near the midline tend to be responsible for functions associated with…
A
the body’s center, including posture
15
Q
T/F Cerebellum modulates ipsilateral muscles while the motor cortex acts on contralateral muscles
A
T
16
Q
Cerebellar damage can cause
A
degrade in motor capabilities
17
Q
T/F Cerebellar damage can cause full paralysis in movements
A
F, it never causes this rather it degrades the motor capabilites
18
Q
Information flowing through these cerebellar loops allows it to modulate
A
motor processing
19
Q
vestibulocerebellum receives input from .. and projects to ?
A
vestibular nuclei ( the same for both)
20
Q
what happens if the vestibulocerebellum is damaged
A
leads to difficulty with balance and postural instability
21
Q
spinocerebellum receives what kind of information and from where…. and where does it project to ?
A
receives somatosensory and kinesthetic info, from the spinal cord and projects it back to the spinal cord
22
Q
damage to the spinocerebellum results in
A
difficulty with the smooth control of movement and movement of proximal muscles like coordinating the trunk and leg muscles for walking
23
Q
cerebrocerebellum receives input from
A
many diff regions of the cortex like motor and association cortices
24
Q
cerebrocerebellum is involved in the regulation of
A
highly skilled movement that requires complex spatial and temporal sequences involving sensorimotor learning
25
examples of sensorimotor learning is
throwing a pitch
serving a tennis ball
juggling
fluent writing and speaking
26
cerebellar ataxia
difficulties in coordinating movement after cerebellar damage
27
cerebellar dysarthria
difficulty in speech output after cerebellar damage
28
what is the traditional test for cerebellar ataxia
have a patient touch his/her nose and then the neurologist finger
29
how does the traditional test for cerebellar ataxia display that a person has suffered this
movement can be performed but the path is staggered, jerky, and zigzag, involves overshoot of the target
30
T/F Overshoot of target occurs because activity of agonist and antagonist muscles are not well coordinated
T
31
define action/intention tremor
overshoot of target with staggering and jerky movements
32
Decomposition of movement
difficulty in coordination of multi -joint movements
patient moves one joint at a time in a serial manner
33
Rather than lifting a glass but moving the entire arm, a person with damage to the lateral cerebellar cortex places an elbow on a table, leans forward, adn brings the glass to their mouth, this is an example of
Decomposition of movement
34
T/F An effect of damage of lateral portions of the cerebellum is difficulties in sensory-motor learning after damage
T
35
List the two theories of cerebellar function
Forward model
cerebellum acts as a timing device that provides a clock for events
36
Define forward model
cerebellum helps to predict sensory consequences of motor plans
37
T/F Forward models are influence by feedback from periphery
F, they are not influenced by this
38
T/F Cerebellum is important for Ballistic movements
T
39
T/F Cerebellar lesions impair the ability to make judgements about how long events will take (temporal duration of events)
T
40
Both cerebellar theories are consistent with a role in
coordination, learning, and timing of movement
aspects of higher-level cognition
41
Basal ganglia is composed of
caudate nucleus
putamen
nucleus accumbens
globus pallidus
substantia nigra
subthalamic nucleus
42
Function of basal ganglia
modify movements
43
T/F basal ganglia is able to modify movement through series of somewhat separable loops with cortical regions
T
44
In basal ganglia loops, cortical regions projects to
caudate and putamen
45
In basal ganglia, the output from this structure occurs via _____ to the ____, which projects back to ______
globus pallidus
thalamus
cortex
46
What are the four loops of the basal ganglia
limbic (emotional) circuit
associative (cognitive) circuit
sensory circuit
motor circuit
47
what are the two routes by which information passes through in the basal ganglia
direct route
indirect route
48
direct route contributes to
sustaining or facilitating ongoing action
49
indirect route is important for
suppressing unwanted movement
50
In direct route input to the basal ganglia occurs via inputs that synapse on ____ ____ of ________ ____ neurons of ________ and ______
D1 receptors of medium spiny neurons of the caudate and putamen
51
in the indirect route input ot the basal ganglia occurs via inputs that synapse on
D2 receptors of medium spiny neurons of the caudate and putamen
52
T/F the two pathways of basal ganglia work together in the same direction
F, have been considered to work in opposition to one another
53
T/F the basal ganglia is important for the accomplishments of movements that may take some time to initiate or stop
T
54
T/F Cerebellum plays a role in movements that are modified once they have been initiated
F, It is not modified
55
why is the basal ganglia thought to assist in motor planning and learning
they receive both motor and nonmotor , especially when motor acts have motivational significance or have a large cognitive contribution
56
what are the multiple roles the basal ganglia are thought to have in motor actions ( there are 4)
1. "setting" the motor system with regard to posture
2. preparing the NS to accomplish a voluntary motor act
3. acting as an autopilot for well-learned sequential movements
4. controlling the timing of and switching between motor acts
57
Primary motor cortex (M1) function
provides the command signal to drive motor neurons to make muscles move
58
what happens when Primary motor cortex is damaged
a person cannot control the force with which muscles are exerted , may result in hemiparesis (worst case scenario)
59
hemiparesis
inability to make motor movements on one side of the body , damage to M1
60
what determines the direction of the movement
summed activity across the population of neurons, they have a preferred orientation to a specific way
61
anterior cingulate important for
selecting among particular responses and monitoring whether the execution of those actions occurred appropriately
62
Parietal regions involved in
linking movements to extrapersonal space and sensory info, as well as linking movements to meaning
63
why is the anterior cingulate considered a high level region
controls diff possible motor sequences
resolves conflict between which motor sequences should be implemented
evaluates the success of motor sequences
64
Primary motor cortex function
control the force and/or direction with execution of motor plans
65
what regions are involved in specifying, preparing, and initiating of movement?
premotor region
supplementary motor complex
frontal eye fields
66
what structures are in the lateral regions
primary motor cortex
premotor cortex
frontal eye fields
parietal cortex
67
what structures are part of the medial regions
anterior cingulate cortex
supplementary motor complex
68
major role of cortical regions in motor control is in
planning and guiding skilled movements
movements that require linking sensory inputs with motor outputs
69
cortical regions support a range of motor abilities including...
picking up an object
producing a gesture in response to a verbal command
moving the eyes to explore an image
70
T/F Regions involved in motor control are distributed across both lateral and medial portions of the brain
T
71
Huntingtons disease is characterized by
hyperkinesias
chorea
athetosis
72
Athetosis
involuntary writhing contractions and twisting of the body into abnormal postures
73
chorea
uncontrollable, jerky movements such as twitching and abrupt jerking of the body
74
hyperkinesias
involuntary undesired movements
75
what are effects of basal ganglia damage
huntington's disease
parkinson's disease
76
what pathways does the huntington's disease affect
indirect pathway
77
parkinson's disease is characterized by
akinesia
bradykinesia
tremors
78
akinesia
inability to initiate spontaneous movement
79
bradykinesia
slowness of movement
80
parkinson's disease affects what pathway
direct pathway
81
why is the direct pathway affected in parkinsons
death of cell bodies in the substantia nigra
82
T/F Parkinsons results in the indirect pathway becoming overactive
T
83
If the internal portion of the globus pallidus is overactive then this inhibits _____ and results in ____
thalamus
decreased motor activity
84
what kind of neurons is lost in huntington's disease and what kind of NT does it bind to
striatal neurons that bind to GABA
85
What neurons give rise to the indirect pathway from the striatum to Globus pallidus
striatal neurons that bind to GABA
86
In huntington's diseases there is a loss of inhibitory input to ______ causing it to become more active resulting in _______
external globus pallidus
increased inhibition of the subthalamic nucleus
87
T/F in huntington's disease the subthalamic nucleus excites the internal section of GP , increasing output from GP, increasing the inhibition of the thalamus leading to less motor activity in the cortex
F,
it inhibits internal section of GP , reduces output from GP, lessens inhibition of thalamus, and leads to motor activity in the cortex
88
What are the three theories of the basal ganglia
1. basal ganglia facilitates the synchronization of cortical activity underlying the selection of appropriate series of movements while inhibiting inappropriate ones
2. basal ganglia breaks down complex actions into chunks of individual actions into coordinated, stereotyped, adn habitual units of action
3. basal ganglia aids the ability to execute movements with varying vigor, that is, over a range of speeds, amplitudes, and frequencies
89
what are the two types of neurochemical methods
positron emission tomography
magnetic resonance spectroscopy
90
what are the function of neurochemical methods (general)
provides information about chemical function related to brain/neuronal activity
analyze/measure neural activity while a person is doing a task
91
what are the technical limitations of neurochemical methods (general)
limitations in gathering info on the compounds involved
concentration cannot be localized to a very precise location in the brain tissue
92
how does a PET scan works
works by altering molecules to have a radioactive atom (isotope) and then introducing them into the blood supply to be carried to the brain
93
how can you tell when an isotope binds to different chemicals in PET?
when there is a release in energy that can be seen/measured by the PET scanner
94
T/F Patients take a radioactive tracer which binds to some cells giving a measure of NT function
T
95
T/F PET is used more often in studies to understand the bases of cognitive and emotional function than an fMRI
F, its not often used in these kind of studies if anything the fMRI is used for this because of its fine temporal resolution
96
what kind of information is provided by a PET scan
neurotransmitter function
distribution of NT binding
absolute levels of brain metabolism
97
in PET scan it is the gold standard for obtaining three things what are they
an absolute measure of regional cerebral blood flow (rCBF)
the cerebral metabolic rate of oxygen consumption
cerebral glucose metabolism
98
T/F MRI cant be tuned to specific atoms
F, they can be tuned to specific atoms
99
in a magnetic resonance spectroscopy in order for the method to be detectable the concentration of the substance must be
quite high
100
purpose of magnetic resonance spectroscopy
can be utilised to examine biologically active substances whose concentration in the brain are high
101
N-acetylaspartate (NAA) when reduced is though to
index pathological processes acting upon neurons and glia
102
MRS is limited in two ways, what are they
1. spatial resolution is not very good ( worse than PET), provides only gross info on the location of these substances within the brain
2. concentration of the substances must be quite high to be detectable
103
Functional magnetic Resonance Imaging function
measures brain blood flow in different regions
104
what is the technique thats most commonly used by cognitive neuroscience
BOLD (blood oxygen level dependent) signal
105
what can we tell from a BOLD signal
based on the fact that oxygenated blood and deoxygenated blood have different magnetic properties
106
How does oxygenated blood differ in magnetic properties from deoxygenated blood
oxygenated blood contains more Fe2+ so it reacts more with the blood scanner
107
T/F deoxygenated blood makes the static magnetic field homogenous making it easier to detect a signal change
F, it makes the static magnetic field inhomogenous making it harder to detect signal change
108
why is it harder to detect signal change in deoxygenated blood in terms of its magnetic properties
theres not alot of Fe2+ reaching with the magnet
109
T/F in a BOLD signal easier to detect deoxygenated blood than oxygenated blood
F, its the other way around
110
when the area of the brain is active, the local _____ of oxygen-rich blood is _____ than the amount of oxygen that can be extracted by the brain tissue
increase
greater
111
decrease in deoxygenated blood results in
increased signal form that region
112
what is a hemodynamic effect
occurs when you get the increase signal from the regional blood flow changes (slide 29)
113
advantages of fMRI
MRI machines are widely available
noninvasive (no high energy radiation is involved)
multiple scans can run on a single individual
can be used on children and women of reproductive age
114
fMRI provides a _____ brain activity over ____ than _____
measure
seconds
minutes
115
T/F fMRI scan provide info only about average patterns of activation across groups of individuals and not specific individuals
F, it can also prived info for specific individual s
116
task-based approaches
examines brain activity in fMRI during the performance of a task
117
what kind of devices is required in task-based approaches and why
requires special non-metallic devices to convey information to the participants and to record their response
118
T/F fMRIA studies typically examine the change in signal form on condition/task to another condition (baseline)
T
119
classical models argue what about motor cortex organization
organized so that different subregions of motor cortex control action of specific portions of the body like fingers,arms, or legs
120
what do alternative models propose about the motor cortex organization
may be organized with regards to actions relevant for survival like reaching and defensive action
121
define motor plan
abstract representation of intended movement
122
T/F supplementary motor complex and premotor areas are involved in creating a motor plan
T
123
what does the brain do before movement commences
generates an entire plan and transmits it to the motor cortex
124
coarticulation
differences in how the vocal muscles produce sounds
125
what specific cortex comes up with the motor plan at the most abstract level ( sequencing critical pieces)
supplementary motor complex
126
T/F primary motor regions execute the commands to move muscles
T
127
What do premotor areas due in terms of the motor plan that has been established by the supplementary motor complex
codes for the types of actions that must occur to meet that motor plan
128
role of supplementary motor complex
planning
preparing
initiating movements
129
what are the three subregions of the supplementary motor complex
pre-supplementary motor area
supplementary eye field
supplementary motor area
130
pre-SMA function
selects what actions should be implemented
131
function of supplementary eye field
planning of eye movement
132
function of supplementary motor area
plans movement of body parts other than the eyes
133
T/F SMC important in planning the sequence and order in which actions occur
T
134
Where does the SMC project to in the motor cortex
Ipsilateral and contralateral motor cortex
135
how is SMC different from primary motor cortex
activation is predominantly observed contralateral in motor cortex rather than both as compared to SMC
136
What are the subregions in premotor regions
dorsal premotor area
central premotor area
137
function of dorsal premotor area
processes motor significance of sensory. cues
coding what type of motor action is chose or selected based on sensory info
138
function of central premoto area (PMv)
involved in implementing motor programs and adjust them so that objects can be manipulated
139
what kind of neurons are found in PMv and what do they do
mirror neurons
fire both when an action is performed and when another organism is performing the same action
140
FEF function
involved in planning and controlling voluntary execution of eye movements
141
function of anterior cingulate cortex
aids in planning and execution of movement
142
what are the three divisions of the anterior cingulate cortex
caudal region
middle region
anterior region
143
function of caudal region of the anterior cingulate cortex and what it connects
connects to primary motor cortex and parietal lobe
modulates or override actiity during simple motor tasks
144
middle region of anterior cingulate cortex connection and function
connects to premotor cortex
modulate selection of movements
145
anterior region of anterior cingulate cortex connection and function
connects to dorsolateral PFC
modulates goal directed info in mind and working memory
modifies more complex motor actions/active when high degree of conflict exists
146
how is the anterior cingulate cortex organized
topographically
147
Right inferior frontal cortex suggested to play a role in
interrupting/inhibiting motor actions
altering actions based on the envt rather than inhibiting
148
how was the role of the right inferior frontal cortex assesed
via the stop-signal paradigm
149
define the stop-signal paradigm
participant press a button whenever a stimulus appears
150
greater damage to the right inferior frontal cortex is associated with what in the stop-signal paradigm
more difficulty on the stop signal task
151
parietal lobe is sensitive to
propioceptive info
kinesthetic infor
152
proprioceptive info is
type of sensory info received from internal snesors in the body
how things feel
153
kinesthetic info is
info about actual movement of body parts
154
T/F Propiceptive info can be sent forward to premotor and primary motor regions to enable selection of appropriate motor program, provide a feedback
T
155
Superior regions of pariteal lobe funtction
acts as an interface between movement and sensory info, so limb/eyes can be guided correctly during motor acts
156
damage to superior region of parietal lobe
inability to guide limbs in a well controlled manner
misreach
157
inferior regions of parietal lobe function
ability to produc complex well learned motor acts
158
damage to inferior parietal regions
leads to apraxia , unable to perform task/movements when asked to do so
159
T/F apraxia is only limb related
F, it is also speech related
160
four major symptoms of parkinsons disease
tremors
cogwheel rigidity ( stiff movement)
akinesia/bradykinesia
disturbances of posture
161
T/F there is a loss of dopaminergic neurons in the substantia nigra in parkinson's disease that affects the indirect pathway
F, it is the direct pathway
162
in parkinson's why is there a delay in symptom onset
the brain tries to compensate for the loss of dopamine in a number of ways
163
how can the severity of rigidity and bradykinesia be directly predicted by the degree of dopamine depletion be measured
PET
164
T/F Parkinson's may also involve alterations in neural synchrony
T
165
T/F there is a clear mechanism that produces tremor in parkinson's
F, the mechanism is not clear
166
what is the drug used to increase the level of DA in parkinson's
L-DOPA
167
L-DOPA side effects
alter person's mood
leads to euphoria/depression
interfere with memory and ability to pay attention
can lead to impulse control disorders
hallucinations
delusions
168
list experimental theories for parkinson's disease
grafting into striatum of fetal tissue rich in DA-producing cells
deep brain stimulation
169
define DBS ( deep brain stimulation)
electrodes are implanted into the brain to stimulate tissue
170
T/F Huntington's disease produces abnormal movements, cognitive deficits , and psychiatric symptoms
T
171
What is the main motor symptom of huntington's disease
chorea
172
T/F dystonia is present in parkinson's
F, its present in huntington's
173
define dystonia
slower movements caused by increased in muscle tone and contractions
174
in huntington's where is the most atrophy found
striatum
175
What is tourette's syndrome
rare disorder that manifests as vocal or motor tics, which are repetitive involuntary movements of a compulsive nature
176
T/F tourette's syndrome is manifested in adulthood before age 25
F, it is in childhood before 11 years
177
what brain structures are dysfunction in tourette's syndrome
basal ganglia and associated cortical-striatal-thalamic-cortical brain circuitry
178
Define apraxia
inability to perform a skilled, sequential, purposeful movement that cannt be accounted for by the disruptions in more basic motor processes
179
T/F apraxia disrupt the ability to pursue specific plans of motor action or to relate motor action to meaning
T
180
what are the two types of apraxia ( Liepmann, 1905)
ideational apraxia
ideomotor apraxia
181
define ideational apraxia
impaired ability to form an idea of intended movement
dont know how to use a specific object but can perform movement
182
define ideomotor apraxia
disconnection between the idea of movement and its execution
you know what you use the object for but you cant execute motor movement
183
oral (buccofacial) apraxia is
facial movements are disordered
184
lesions that lead to apraxia are
typically observed after parietal or frontal lesions of the L hemisphere
185
define praxis
conception
planning
and production of skilled movement
186
T/F there is no agreement on the lesion location that leads to apraxic behavior
T
187
constructional apraxia
items cant be correctly manipulated with regard to their spatial relations
188
dressing apraxia
difficulty in manipulating and orienting both clothes and his/her limbs so that clothes can be put on correctly
189
callosal apraxia
disconnection syndrome that is inability to perform a skilled motor act with the L hand in response to a verbal command
190
retinal tissue is derived from
neural tissue during embryological development
191
Retina contains
several layers of cells at the back of the eye that register light
192
Retina function
begin initial steps of representing visual world by registering light
193
list the two types of photoreceptor cells
rods and cones
194
function of photoreceptors
take light energy and transform it into electrochemical energy used in the nervous system
195
where does parallel processing beigin
in retina with division of the sensory receptors into rods and cones
196
characteristics of rods
contain one pigment , rhodopsin
used in the dark to contrast light vs dark
located more in the periphery
feed into ganglion cells
197
rhodopsin
sensitive to small amounts of light
198
characteristics of cones
function in broad daylight
three types of cones R,B,G
sensitive to wavelengths of the light spectrum
packed more densely in center of fovea
visual acuity
199
ganglion cells function
sends info from eye to the brain
200
location of ganglion cells
in the retina
201
where do the ganglion cells axons stretch toward to
the brain an d form the optic nerve
202
What are the two main types of cells in ganglion cells
M cells
P cells
203
M cells function
responsive to coarse pattern and detect rapid motion
204
P cells function
preserve color information
much smaller
205
T/F there are as many as 20 distinct types of ganglion cells which are distributed across the retina in mosaic patterns
T
206
what are receptive fields
refers to that specific region of visual space to which a particular cell responds
relative to the position of the head and the eye
207
T/F brain knows where light has struck by knowing which ganglion cells are excited
T
208
receptive fields of the retinal ganglion cells have a
center surround structure
209
Define on center off surround structure
where light falls at a particular spot its going to excite nearby ganglion cells if it falls outside that spot then it will inhibit
210
what are the two destination for visual info that travels out of the eye along the optic nerve
superior colliculus
lateral geniculate nucleus
211
The tectopulvinar pathway functin
allows people to orient quickly to important visual info - motion detection
212
The geniculostriate pathway function and where axons terminate
enables perception of color and detail
axons terminate in the LGN
80% of ganglion cells go through here
213
fMRI results are usually maps that show
which voxels are significantly more activated in one condition than another
214
in an fMRI what color shows greater activation, what about mild activation
yellow orange = greater
blue = mild , distracting info
215
define region of interest (ROI)
process of looking precisely at a specific region of the brain after whole brain analysis
216
4. Which scan is good at assessing glutamate, GABA and NAA?
MAGNETIC RESONANCE SPECTROSCOPY
217
the assessment of which scan uses ROI
Functional Magnetic Resonance Imaging
218
A multivoxel pattern analysis provides what type of information
provides info about level of activity and pattern across brain regions
219
disadvantages of fMRI scans
objects cannot be distinguished by the degree of activation alone
220
resting state approaches examine
patterns of activity over time while the brain is simply at rest
221
advantages of resting state approaches
can be used with infants and elderly
short neuroimaging session
222
Disadvantages of resting stat approaches
cant be used for functional task analyses
does not tell you about activation corresponding to anything involving a task
223
define functional connectivity
looks at correlation between brain activation in different regions in the process of completing a task
224
EEG are best at providing
temporal resolution of any measure of brain activity
225
disadvantages of EEG
does not provide a good measure of exactly where in the brain activity is occuring
226
gamma/delta waves tells us
person is sleeping
227
alpha waves indicate
person is awake/relaxed state
228
beta waves indicate
person is awake and engaged in cognitive activities
229
define ERP
brain activity that is recorded in reference to a specific event
230
exogenous ERP
occurs in response to an external event
231
Endogenous ERP
occurs in response to an internal event
232
what is MEG
records magnetic potentials produced by brain activity
233
advantages of MEG
no interference
strength of magnetic field recorded outside of head can help provide some info about how deep within the brain the source is located
234
disadvantages of MEG
very expensive because it requires a special magnetically shielded room to shield against earths magnetic field
235
what are the two techniques for modulating brain activity
transcranial magnetic stimulation
transcranial direct current stimulation
236
how does TMS work
1. a pulsed magnetic field over the scalp induces electrical field
2. induced electrical field alters membrane potential
3. once pulse magnetic field is discontinued the neurons can return to their previous state
237
why do we use TMS
increase neuronal activity or decrease it
238
what method is most effective for cortical structure
transcranial magnetic stimulation
239
how does tDCR work
weak electrical current runs through the scalp,skull, and braine between entrance and exit electrode
240
how do we now whether neuronal activity is increased or decreased in tDCS
brain area stimulated below anodal electrode = increase activity
brain area stimulated below cathode = decrease activity
241
what does TMS do
method used to either disrupt activity and create a virtual lesion or enhance activity
242
tDCS compared to TMS
1. stimulation is less intense making it safer but not as experimentally powerful
2. less focused spatially, so not helpful in determining linkages between specific brain regions and behavior
243
structures involved in the geniculostriate pathway
involves the LGN
244
structures involved in the tectopulvinar pathway
superior colliculus and pulvinar nucleus of thalamus
245
T/F tectopulvinar pathway is slow-acting
F, it is very fast acting
246
what type of ganglion cells does the tectopulvinar pathway receives most of its input from
M (magnocellular) cells
247
in the tectopulvinar pathway ____ info from the ____ is sent to _____
visual, retina, superior colliculus
248
what regions can the superior colliculus sent its projections to and why
motor regions to control eye and head movements
249
in the geniculostriate pathway after axons terminate in the LGN where do they project to
striate cortex/primary visual cortex (V1)
250
T/F there are 6 main layers in the LGN that are stack on top of one another and folded into a knee-like shape
T
251
hat kind of input does each LGN layer recieve
input from one eye but info is from the contralateral visual field
252
What are the three section of layers found in LGN, their function what kind of cells are found there
Magnocellular layer - receives input from M cells for motion detection
Parvocellular layers- receive input from p cells and detect color and detail
Koniocellular layer - small cell layer in b/w main layers
253
where can we find primary visual cortex ( AKA striate cortex/V1)
in the occipital lobe
254
what is the primary visual cortex
first destination within the cortex that receives projections from the LGN
255
define cortical magnification factor of striate cortex
the millimeters of cortical surface that are devoted to one degree angle in the visual world
256
what structure is the cortical magnification much higher
fovea
257
what are the cells that organize the striate cortex
simple, complex, and hyper-complex
258
what are the receptive fields for the different cell types of the striate cortex
simple cell- responds to bars of different orientations
complex cells- respond to certain line orientation but less picky about where exactly line is located
hyper-complex- prefer lines of certain lengths
259
why do we need binocular vision
to be able to perceive the depth perception
260
define binocular disparity
refers to the fact that an image that falls on each retina is slightly different as the eyes are position in different locations
261
cells in layer 4 of striate cortex are ______ but connect with cells in other striate layers in ways that allow ____________ ___ ________ from both eyes
monocular
convergence of information
262
cerebral achromatopsia is caused
POSTERIOR VENTRAL CORTEX
263
what is cerebral achromatopsia
a person can not perceive color only see shades of gray
264
Area V4 cell functions
sensitive to color that is able to allow someone to perceive color
265
what is blindsight
people have no conscious experience of seeing ( damage to striate cortex)
266
define cortical blindness
blindness of cortical origin and not a problem in the eye or optic nerve, doesn't always cause complete blindness
267
what can be inferred from cortical blindess
primary visual cortex is necessary for conscious awareness of the world
268
what are the two main routes where info travels when it leaves the striate cortex
ventral and dorsal stream
269
ventral stream
what path, identifies objects
270
dorsal stream
where path , represent spatial locations of objects
271
what are differen sensory features in audtion
pitch , loudness, and time of sounds
272
what structure is found within the inner ear
cochlea
273
function of cochlea
contains cells that translate sound energy into neural impulses
274
describe the auditory pathway from cochlea to cortex ( include it for both ears)
spiral ganglion --> dorsal cochlear nucleus ---> inferior colliculus --> MGN ---> auditory cortex
spiral ganglion --> ventral cochlear nucleus ---> superior olivary --> lateral lemniscus --> inferior colliculus ---> MGN ---> auditory cortex
275
275
what are coincidence detectors
cells that take into account the different arrival times of a sound at the L and R ears
276
define tuning curve
shows cells snesitivity across different sound frequencies
277
T/F sound and sight are not associated with eachotehr
F, the must be associated with each other
278
location of auditory cortex
beneath the sylvian fissure in the temporal lobe
279
how does the coincidence detector relate to the delay line method
delay line method ensures that inputs from different sources are temporally coordinated, allowing coincidence detectors to operate effectively in tasks requiring precise temporal integration of sensory information.
280
Another name for V1, Brodmann area 17 and striate cortex
Primary visual cortex
281
feedback connections to the LGN
allow cortex to actively influence input that it will receive from LGN, direct no crossing over
282
if someone is using a hairbrush as a telephone they are showing signs of:
a. ideational apraxia
b. callosal apraxia
c. ideomotor apraxia
d. dressing apraxia
A
explanation:
there's an object, and they're able to use the object. But They're using it for the wrong purpose, because they don't have the idea behind what the object is used for.
283
how is the striate cortex different from LGN
V1 processes info from both eyes
LGN processes info from one eye ( separates them )
284
area V2, V3, V4 are mapped
retinotopically ( b/c image stays as a whole )
