Chapter Two - Cognitive Neuroscience Flashcards
1
Q
What are the 2 types of experiments involved in studying the mind?
A
- behavioral experiments
2. physiological experiments
2
Q
What is cognitive neuroscience?
A
- study of physiological basis of cognition
- understanding of nervous system + individual units that comprise that system
3
Q
What are examples/methods of the behavioral approach?
A
- measures relationship between stimuli and behavior
- RT
- proportion of errors
- verbal protocols/self report
4
Q
What are examples/methods of the physiological approach?
A
- measures relationship between physiology and behavior
- EEG/ERP
- heart rate, skin conductance etc.
- PET
- fMRI
5
Q
What are the variables of the memory consolidation study?
A
independent:
group 1: learned words right before sleep
group 2: learned words long before sleep
dependent: memory (percent forgotten) 2 days later
6
Q
What were the behavioral results of the memory consolidation ex.?
A
awake group showed higher percent of forgetting
7
Q
What were the physiological results of the memory consolidation ex.?
A
- differential brain activity in the hippocampus
- increase in sleep group
- decrease in awake group
8
Q
What did anatomists first believe the structure of the brain to be?
A
continuous nerve net
9
Q
What did Camillo Golgi find in 1870 with better staining techniques?
A
structure of a neuron
10
Q
What method did Santiago Ramon y Cajol use?
A
-Golgi’s staining technique on tissue from brains of newborn animals
11
Q
What was Ramon y Cajol’s major idea?
A
neuron doctrine
12
Q
What is the neuron doctrine?
A
- individual cells transmit signals in nervous system
- cells not continuous with other cells
13
Q
What are Caja’s 4 major findings?
A
- synapses
- neural circuits
- receptors
- specialized cells to create, receive + transmit info
14
Q
dendrites
A
- multiple branches reaching from cell body
- receive info
15
Q
cell body
A
- contains mechanisms to keep cell alive
- contains nucleus
16
Q
myelin sheath
A
- fatty tissue
- electrical insulator
- facilitates propagation
17
Q
nodes of ranvier
A
- gaps in myelin
- regenerates AP
18
Q
synapse
A
- junction between nerve cells
- diffusion of NT
19
Q
axon
A
-tube that transmits AP
20
Q
What are microelectrodes?
A
-small shafts of conductive solution that pick up electrical signals
21
Q
What are the 2 parts of a microelectrode?
A
- recording electrode: recording tip inside nueron
2. reference electrode: located some distance away
22
Q
What is resting potential?
A
-difference in potential between 2 electrodes when neuron is not firing
(-70 mV)
23
Q
What is the voltage of a neuron when an AP fires?
A
+40mV
24
Q
What is an action potential?
A
-mechanism through which info is transmitted in the nervous system
25
Each action potential travels down axon without changing its _____ or ______
height or shape
26
what is a synapse?
-space between axon of one neuron + dendrite of another
27
What happens when the AP reaches the end of the axon?
- synaptic vesicles open
| - release chemical NT
28
What do NT do once released?
- cross synapse
| - bind with receiving dendrites
29
What are neurotransmitters?
-chemicals that affect electrical signal of receiving neuron
30
What is an excitatory NT?
increases chance neuron will fire
31
What is an inhibitory NT?
decreases chance neuron will fire
32
do all signals lead to action potentials?
no
33
When does an action potential result?
-only if threshold level is reached
34
rate of neural firing is related to _____ of stimulation which in turn is relation to the_____ of the ______
- intensity
| - magnitude of the experience
35
Is everything a person experiences based on direct contact with stimuli?
- no
| - representations in person's nervous system
36
What did Hubel + Wiesel study?
representation in one neuron
37
What are feature detectors?
neurons that response best to a specific stimulus
| EX: orientation, movement, lenght
38
What did Charles Gross do?
-performed experiment in which he recorded form single neurons in monkey's temporal lobe
39
What did Charles Gross find?
- found neurons that refused to respond to any "simple" stimuli of lines, circles etc.
- neuron fired in mistake to hand shadow
- found neurons that only respond to faces
40
What is the difference between neurons in visual cortex + neurons in temporal lobe?
visual cortex: simple shapes
| temporal lobe: complex geometrical stimuli
41
What is hierarchical processing?
-ascension from lower to higher levels in brain corresponds to perceiving objects that move from simple to higher levels of complexity
42
What is sensory coding?
how neurons represent various characteristics of the environment
43
What is specificity coding?
- representation of a specific stimulus
| - by firing of specifically tuned neurons specialized to just respond to a specific stimulus
44
What is population coding?
- representation of a particular object
| - by the pattern of firing of a large number of neurons
45
What is sparse coding?
- when a particular object is represented by a pattern of firing only a small group of neurons
- majority of neurons remaining silent
46
what does localization of function mean?
specific functions are served by specific areas of the brain
47
What is the cerebral cortex?
- 3mm thick layer that covers the brain
| - contains mechanisms responsible for most of our cognitive functions
48
ipsilateral
same side
49
contralateral
opposite side
50
bilateral
both sides
51
unilateral
one side
52
proximal
close to trunk
53
distal
far from trunt
54
efferent
away from
55
afferent
towards
56
What are 3 planes of bisection?
1. coronal
2. axial
3. sagittal
57
What is grey matter?
contains nerve cell bodies
58
what is white matter?
contains myelinated axons
59
What are the 4 lobes?
frontal - reasoning, planning, language
parietal - integrating sensory info, touch, temp
temporal - auditory, language, memory, smell
occipital - visual
60
Broca's aphasia
- language production impaired
| - left frontal lobe
61
Wernicke's aphasia
- language comprehension impaired
| - left temporal lobe
62
What did studies of soldiers in WW1 show?
-damage to occipital lobe results in blindness
63
What is the result of damage to the left part of visual cortex?
-blindness in upper right part of visual space
64
What is prosopagnosia?
-an inability to recognize faces
65
What is alexia?
inability to recognize text, read
66
What is semantic agnosia?
object blind
67
What is tactile agnosia?
inability to feel touch
68
What is double dissociation?
- damage to one part of brain causes function A to be absent while function B is present
- damage to another area causes function B to be absent while function A is present
69
What does double dissociation allow us to conclude?
- function A and B served by different mechanisms
| - operate independently
70
What is a benefit of double dissociation?
-allows us to identify functions that are controlled by different parts of the brain
71
How does double dissociation work with faces?
- can't recognize faces (function A)
| - can recognize objects (function B)
72
What is MRI?
- magnetic resonance imaging
| - images structures within brain
73
What is an fMRI?
- functional magnetic resonance imaging
| - determines neural activity/functioning of the brain via blow flow
74
How is blood flow measured?
- oxygen in blood carried by hemoglobin
| - hemoglobin contains a ferrous molecule (iron)
75
What happens in areas of activity during an fMRI?
- more oxygen used
- more iron
- more magnetic signal
76
What are 3 advantages of MRI?
1. good spatial resolution
2. no radiation
3. differentiates tissues
77
What are 3 disadvantages of MRI?
1. expensive
2. can't have metal
3. takes longer (than CT)
78
What does an fMRI measure?
- Blood Oxygenation Level Dependent (BOLD)
- measures probabily that region has increased blood flow according to Z/Tscores
- quantifiable difference
- NOT SEEING ACTUAL BLOOD FLOW
79
What are 3 types of neuroimaging experimental designs?
1. block design
2. event-related design
3. resting state
80
What does the FFA respond to?
- fusiform face area
| - responds specifically to faces
81
Where is the FFA?
temporal lobe
82
What is happens when there is damage to the FFA?
prosopagnosia
83
What is the PPA?
- parahippocampal place area
| - responds specifically to places (indoor/outdoor scenes)
84
Where is the PPA?
-temporal lobe
85
What is the EBA?
- Extrastriate body area
| - responds specifically to pics of bodies + parts of bodies (not faces)
86
Where is the EBA?
-occipital lobe (visual cortex)
87
What is distributed representation?
-specific functions processed by many different areas of the brain
88
What is the two-stream hypothesis?
ventral + dorsal pathways
89
What is the ventral pathway?
- "what" pathway
| - processes identity of perceived object
90
What ist he dorsal pathway?
- "where pathway"
| - processes location of perceived object
91
What are neural networks?
- groups of neurons/structures
| - connected + together allow for overall experience
92
What is an example of a neural network?
- pain network
a. locational + sensory aspect
b. emotional aspect
c. significance
d. attentional aspect
e. memory
93
What is functional connectivity?
-regions in brain that have similar patterns of activity over time
94
What is structural connectivity?
-neuroanatomy, measures connectivity of neurons
95
What is MVPA?
- multivoxel pattern analysis
- applies machine learning techniques to neuroimaging data
- looks at distributed patterns of neural activity
96
What are 3 things that MVPA allows us to do?
- decode percepts/thoughts (mind reading)
- decode brain patterns
- characterize distributed representations
97
What are 5 steps to MVPA analysis?
1. acquire brain data in different conditions
2. generate brain patterns of activity across voxels
3. label patterns
4. train a classifier
5. apply classifier to new patterns
98
What are 3 examples of MVPA?
1. identifying emotion
2. identifying neural markers of mental illness
3. new understanding sensory processing in brain
99
What are 3 common pitfalls of neuroimaging analysis?
1. multiple comparison problems
2. reverse inference
3. voodoo correlates + double dipping
