MIDTERM #3 Flashcards
(141 cards)
1
Q
Our brains do not directly obtain sensory information so how is it obtained
A
Multiple nervous system networks that process a specific type of sensory information
Ex: sight, touch, hearing, smell
2
Q
Each sensory system has a _____ that encodes info about a physical feature of our environment as changes in _______
A
Specialized receptor, membrane potentials
3
Q
What are specialized receptors
A
Neurons with modifications to its structure
Best responds to a specific external stimuli
Each process a different form of info
4
Q
What are photoreceptors
A
Light sensors
Encode light (photons) as electrochemical signals
5
Q
What are discrete packets of light
A
Photons
6
Q
The number of photons represents
A
Brightness
7
Q
The photons’ wavelength represents
A
Color
8
Q
What is the stricture of a photoreceptor
A
They are filled with disks that contain rhodopsin proteins
9
Q
What are rhodopsin proteins
A
Specialized G proteins activated when struck by a photon
10
Q
What happens with photons hit rhodopsin
A
Activate G proteins
G proteins will interact with ion channels, changing membrane potential
Encodes light as change in membrane potential
11
Q
What are the two classes of photoreceptors
A
Rods
Cones
12
Q
Which photoreceptor responds best to low-light environments
A
rods
13
Q
Which photoreceptor has more disks
A
Rods
14
Q
Low number of photons lead to compromises in
A
Resolution
Non colored vision
15
Q
Which photoreceptor responds best to high-light environments
A
Cones
16
Q
Which photoreceptor has less discs
A
Cones
17
Q
What are the three cone types and what color do they correlate with
A
Short: blue
Medium: green
Long: red
Think: ROYGBIV
18
Q
Do cones work in isolation?
A
No, they use population coding
Summate relative activity to represent something more complex with increased accuracy
19
Q
How does color blindness happen?
A
When one or more of the cones are not working properly
20
Q
How does red-green color blindness occur
A
Malfunctioning medium/long cones
21
Q
True or false: photoreceptors can adjust to environment
A
True: by relative activity
22
Q
What is the retina
A
Structure on the back of the eyeball that is a collection of over 100 million photoreceptors
23
Q
How does the flow of info work in the retina
A
1) photons will travel through multiple layers of cells to reach the photoreceptors in the back of the retina
2) photoreceptors encode number and wavelength of photons as changes in membrane potentials
3) photoreceptors communicate with bipolar cells
4) bipolar cells stimulate retinal ganglia cells (RGC)
5) APs will be sent from RGCs to the brain
24
Q
What is a retinotopic map and how does it work
A
Combining all the info from each point of the retina using population coding
When photons hit a spot on the retina, it will encode the intensity and color of the photons
25
True or false: the location where the photons land on the retina correspond to where the visual info comes from
True
And this forms the retinotopic map
26
What is the optic nerve made of and what is its purpose
RGC axons from all the photoreceptors condense together -> optic nerve
Contains all the visual info from the eye
27
What happens if you cut an topic nerve
Vision loss of the whole eye
28
Where do optic nerves combine together
optic chiasm
29
How does the optic chiasm work?
Splits info from other eye in half and then combines it with info from the other eye
30
How does the visual pathway work
Encoded info from photoreceptors passes through bipolar cells to the RGCs
RGC axons from all photoreceptors form the optic nerve -> optic chiasm -> optic tract -> optic radiation -> V1
31
Where is the left and right visual field formed
The optic chiasm
32
What is the purpose of the optic tract
Connects to the thalamus (LGN)
33
What are the axons leaving the thalamus called
Optic radiations
34
What is the role of optic radiations
connect thalamus to the primary visual cortex (V1)
35
What does the left eye’s temporal field link to
right visual field
36
What does the left eye’s nasal field link to
left visual field
37
What does the right eye’s temporal field link to
Left visual field
38
What does the right eye’s nasal field link to
right visual field
39
What would damage to the right optic nerve result in
Loss of all info from the right eye
40
What would damage to the right optic tract result in
Loss of all info from the left visual field
(Left nasal and right temporal)
41
What is the primary visual cortex (V1)
The region of the cortex that does the initial processing of visual info
Then, relays to other brain areas
42
Where is V1 located
Occipital lobe
43
Where does V1 receive info from
the thalamus
44
True or false: there is a V1 on either hemisphere
True: V1 on both left and right hemisphere
45
The left hemisphere V1 processes
the right visual field
46
The right hemisphere V1 processes
the left visual field
47
What is V1 constructed of and what does it correspond with
a column: corresponds with a place on the retina
The columns receive connections from all the rods and cones from a given spot of the visual field
48
What kind of information do V1 columns process
light intensity
Color
Simple movement
BARS OF ANGLES
49
What are bars at diff angles a good way to encode visual info?
very sensitive to edges
Work together to represent something more complicated
50
How are you able to see :) this smiley face?
1) photons from the screen cross the room to the retina in ur eyes
2) APs travel along axons from the eye to your brain (retina -> optic nerve -> optic chiasm -> optic tract -> thalamus -> optic radiations -> V1)
3) individual columns in V1 process info about edges, color, and light intensity of a given part of a visual field
4) columns communicate to represent whole
51
What process makes visual processing so fast and how does it work
Parallel visual processing:
Broken up processes are done in areas specialized for that aspect of vision
Recombined in higher-cognitive areas for a detailed representation
52
What are the two major pathways and what does they correlate with
Dorsal stream: where pathway
Ventral stream: what pathway
53
What is the dorsal stream and where is it located
A collection of brain areas in the parietal lobe
54
Where is MT located and what does it process
An area in the dorsal stream: parietal lobe
Processes how patterns can move
55
What may someone with MT damage on both hemispheres experience
Akinetopsia: motion blindness
56
What is an agnosia
A person is able to see object/action but they are unable to perceive the object/action
57
What is MST located and what does it process
An area in the dorsal stream: parietal lobe
Processes optic flow
= what you see when you’re moving forward (the perception of surroundings when moving
58
When the parietal love is damaged, how does it affect a patient
Unable to process spatial info
59
What happens when one of the parietal is damaged
Hemispatial neglect: a person is unable to process visual field info from the opposite side of damage
60
Where is the FFA located and what does it process
An area in the ventral stream: temporal lobe
61
What did they find in an experiment recording the FFA in a monkey
Strong responses to monkey faces, human faces, drawings of faces
Weak to faces with errors
No response to non-faces
62
True or false: the FFA can also show activity for cars
True: for experts in fields (like a car mechanic)
= FFA may be a visual expert area
63
True or false: the FFA will activate for an upside down face
False
FFA specialized for typical face details = major errors not recognized
64
What occurs with damage to FFA
Prosopagnosia: “face blindness”
65
Where is object categorization processed
The ventral temporal cortex
66
What is the hierarchical coding hypothesis
Leading hypothesis on how we categorize objects
Brain breaks down visual object into each of its foundational components -> feature selective cells in the ventral temporal lobe respond very well specific components -> feature selective cells will use population coding to combine info -> each unique object will generate unique combination of activated cells -> population coding allows complex representation
67
What occurs with damage to the temporal or occipital lobes
Visual Agnosia: inability to recognize objects
Bcuz: temporal processes what it is, damage to dorsal because they work together
68
What is modality
What type of info each sense processes
69
True or false: different modalities acquire, organize, and process info in very similar neural mechanisms
True
70
What is the role of specialized receptors
Encode physical info from environment into APs for brain to process
71
What is the common name, cell type, and encoded info of the visual system,
Name: sight
Cell type: photoreceptors
Encoded info: light (intensity + wavelength)
72
What is the common name, cell type, and encoded info of the auditory system
Name: hearing
Cell type: hair cells
Encoded info: vibrations in air
73
What is the common name, cell type, and encoded info of the somatosensory system
Name: touch
Cell type: mechanoreceptors
Encoded info: vibrations, pressure, pain, temperature
74
What is the common name, cell type, and encoded info of the olfactory system
Name: smell
Cell type: chemoreceptors
Encoded info: chemicals in air
75
What is the common name, cell type, and encoded info of the gustation system
Name: taste
Cell type: chemoreceptors
Encoded info: chemicals in food
76
What is topographic organized and where is it
A structure made of columns, organized for each sensory system based on how the information is obtained
located in the primary sensory cortex
77
Where is all somatosensory information processed and how is it organized
S1: the primary somatosensory cortex
Each column responds to a specific part of the body
78
Where is all auditory information processed and how is it organized
A1: the primary auditory cortex
Each column corresponds with a specific frequency/tone of sounds in a word
79
What are examples of high-level processing regions
the FFA, ventral temporal lobes: multimodal and abstract
80
What are similarities between the sensory systems
- Specialized receptors
- Topographic organization established by receptors
- Primary sensory cortices
- Column organzization
- Hierarchical structure (simple -> complex processes)
81
What processes converts short-term memory to long-term
Consolidation
82
What are the two categories of long-term memory
Declarative: conscious
Nondeclarative: not available to conscious
83
What is an example of declarative memory
History, semantics, daily events
84
What are examples of non declarative memory
motor skills, associations, puzzle-solving skills, priming cues
85
Long-term storage of non declarative memory is believed to be located where?
the cerebellum, basal ganglia, premotor cortex, and more
86
What area of HM’s brain and what did it affect/not affect
the HC
Affected: memory consolidation, creating new episodic memories
Unaffected: short-term memory, recalling into before surgery, learning new motor skills
87
What was HM diagnosed with due to his surgery
Anterograde amnesia: unable to create new memories, inability to consolidate declarative info from short-term to long-term
88
What is LTP and where does it happen primarily
Prolonged synaptic changes
Happens primarily in the HC
89
What happens to a synapse after a strong stimuli
Also becomes stronger…
But only happens at the synapse that experiences the strong stimuli
90
What are the two NT receptors needed for LTP
AMPA and NMDA
91
What is the NT that binds to both AMPA and AMNDA
Glutamate
92
True or false: some glutate will result in plasticity
false
Has to be a great deal of Glutamate to activate many receptors and greatly depolarize the cell
UNLESS there are more/more effective AMPA cells, causing more NA+ to flow into cell
93
What happens when a great deal of Glu is released
1) activates many AMPA receptors -> lots of depolarizing
2) causes Mg2+ to unblock the NMDA receptor
3) Ca2+ will activate proteins in the post synaptic cell
94
How does LTP increase EPSPs and dendritic spines
EPSPs:
Increases # of AMPA receptors
Modifies AMPA receptors to allow more ions through
= depolarization
Enlarges and reinforces dendritic spines: where axons connect to dendrites
95
Briefly summarize LTP
1) strong stimuli allows NMDA receptors to open
2) Ca2+ flows into the cell v
3) Ca2+ activates second messengers
4) which activates gene expression
5) which causes long-term changes that strengthen the synapse
96
Where is memory stored
No centralized location: distributed throughout whole brain, using areas that initially processed the information
97
What is the role of the HC in memory
Communicates with other brain areas important for senses, executive function, emotions, and more
At the top of the visual hierarchy connection map = highly connected with high-level visual processing areas for memory consolidation
98
What is the role of the senses in memory
Sensory areas used to encode initial stimuli activate when recalling stimuli
99
What is the role of the ventral stream in memory
Object categorization areas are the same while observing and remembering
100
How was the role of the dorsal stream in memory demonstrated in a study
Asked patient with hemispatial neglect to recall landmarks around an iconic landmark
Only able to remember landmarks on unaffected visual field
= dorsal stream important for recalling space info
101
What is the evidence that environment can influence emotional perception
There is greater variability for non-European countries and isolated communities in perceiving emotion
102
Why is fear the most throughly investigated emotion in neuroscience?
- consistent across many subjects
- can be quantifiably measured in animal models
- has a possible brain area that regulates it
103
Where is the amygdala located
the temporal lobe, in front of the HC
104
How is mouse freezing affected with an intact/lesioned amygdala
Intact: “fears”/freezes wit CS due to association with CS and foot shock
Lesion: no “fear”/no freezing with CS due to lack of association
105
How did researchers examine the effects of WHEN the amygdala is inactivated
exposed amygdala with a GABA agonist (inhibitory -> hyper-polarizes) before/after fear conditioning
106
Will mice freeze if their amygdala is inhibited before fear conditioning
yes
107
Will mice freeze if their amygdala is inhibited after fear conditioning
no
108
What were the main findings about timing in fear conditioning
inactivated before = mouse does not fear CS
Inactivated after = mouse fears
= amygdala needed to learn what to near NOT needed to recall what to fear
109
The amygdala is known as the fear center but what is it being reevaluated for
the “stimuli association” area
Integrates info of objects/events with reinforcing stimuli -> influences emotions and physiological processes
110
Emotions are most likely regulated by a complex interaction amongst the
Amygdala
PFC
Hypothalamus
111
What were the results of a double dissociation study about fear and HC/amygdala associations
Amygdala is important for association but not declarative memory
… no sweat response but able to recall events before horn
HC is important for declarative memory not association
…. Sweat response but unable to recall events before horn
112
Besides associations, how does amygdala lesions affect people
- patient SM unable to draw “fear”
- struggle to recognize emotions of others
- when watching people talk, watch mouth and background rather than eyes
113
What is the correlation between psychopathy and the amygdala
Reduced connections between the amygdala and the frontal lobe in prisoners diagnosed with psychopathy
Lack of communication between amygdala and PFC may be an important factor in psychopathy
114
What is executive fucntion
Collection of multiple cognitive processes working together to allow you to process information and how one responds to it
115
True or false: executive function is a single thing
False: a collective of different cognitive domains working together
WM + cognitive flexibility + inhibitory control
116
What is working memory
the ability to hold info + modify info over short periods of time
117
What is cognitive flexibility
The ability to change perspective or plan
uses info maintained in working memory to adapt to new info + create response plan
118
What is inhibitory control (+ an experimental example)
Ability to control thoughts, feelings, attention, behaviors to do one thing instead of another
Ex: stroop task
119
What part of the brain is responsible for executive function, motor planning, and motor control
Frontal lobe
120
Where is the central sulcus
The dividing line between frontal and parietal lobe
121
What part of the brain directly controls motor movements and what does it primarily communicate with
The primary motor cortex (M1)
Primarily communicates with:
- PNS somatic motor system
- premotor cortex
122
What is the brain region responsible for planning motor movements
Premotor cortex
123
The premotor cortex is the middle man between _____
The PFC + motor cortex + basal ganglia
Integrates info from PFC + basal ganglia to determine action of M1
124
What is the role of the PFC
- regulates executive functioning
- highest level cognitive processing
- receives info to process/send info to (the premotor cortex + basal ganglia) to regulate other brain areas
125
How is the PFC unique compared to other brain structures
- ability to maintain neural representation to stimuli that is not being observed
- compared to early sensory areas that are only active when exposed to stimuli
126
What was the findings related to the PFC in a monkey experiment
Procedure:
1) monkey shown food reward + where is placed
2) screen lowered so cannot see
3) monkey still grabs food when screen rises
- PFC more active when screen is down because maintains a neural representation of info for the reward
- no activity if no food reward because no info to maintain
127
How does abstract representations of info facilitate executive fucntion
Allows info to be:
1) maintained over time
2) analyzed
3) modified
-> mechanism of “thinking”, allows PFC to collect info, process it, and decide how to respond
Abstract = divorced from original stimuli
Ex: 1020 -> 0201
128
What is the information flow of concrete representations
1) primary sensory cortices (V1, A1, S1, etc) encode info from environment as concrete representations of info
2) info encoded in the nervous system where there is a clear correlation to a cell’s activity and info encoded (ex: retinotopic map)
129
What are the differences between sensory encoding vs high level perception
Sensory encoding:
- monomodal
- concrete representations
- info encoded in nervous system where there is clear correlation between cell’s activity + info encoded
High level perception:
- multimodal
- parallel processing (info divided; ex: V1, ventral + dorsal stream)
- less concrete, more abstract
130
What is the information flow of high level perception
1) info from primary sensory cortices are sent to higher level areas (ex: V1 -> ventral + dorsal)
2) aspects of sensory info divided for parallel processing (more abstract features)
3) high level processing areas send info to the PFC
4) PFC collects info for representations (most abstract)
131
What is the information flow of action in executive function
PFC unable to enact plans alone, needs premotor cortex and basal ganglia
PFC makes the plan -> complex loop of communication between the 3 allows processing all possible motor actions to accomplish goal -> finalized plan ends up in premotor cortex
Premotor cortex communicates with primary motor cortex (M1) -> which communicates with the somatic motor division of the PNS, stimulating muscles
(Neural representations in M1 are concrete)
132
How long does it take to respond to a visual stimuli
200ms = 0.2 seconds
133
When is information abstract vs concrete in the information flow of perception to action
Info is most concrete when entering and exiting the CNS
Most abstract when represented in the PFC
The middle steps (high level processing + motor planning) = mix of concrete + abstract
134
What is the role of concrete representation in info flow of executive functioning
Obtain + send info that is compatible with less complex systems
(Ex: organizing collection of sensory info in a topographic map, stimulating muscles based on body location)
135
What are examples of mixed representation in executive functioning
Mixed representation = brain areas process info which transform it into formats that are compatible w/ end destination
Ex: sensory cortices -> PFC -> motor cortex
136
What would happen with damage to the PFC?
Affects highest level cognitive processes:
- personality
- motivation/planning
- creativity
- attention
- impulse control
And more!
137
What happened to Phineas Gage following his incident
Personality changed: became more disorganized, impulsive, vulgar because…
- his executive functioning was severely damaged, specifically his inhibitory control
138
What was the goal of lobotomies and what were its outcomes
Goal: emotional blunting of psychiatric disorders
Outcomes: patients did not express outward symptoms of their disorders but also did not express
- motivation
- personality
- attentional control
- creativity
139
What were the social impact of lobotomies
Widely accepted from 1930-1950, unproportionally affecting marginalized communities:
- individuals w/ neurological disorders
- women
- LGBT community
140
What ultimately caused lobotomies to be phased out
Discovery of anti-psychotic medications
141
What brain area is where information is collected, processed, and sent out
The PFC
