Chapter Two - Cognitive Neuroscience Flashcards Preview

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Flashcards in Chapter Two - Cognitive Neuroscience Deck (99):
1

What are the 2 types of experiments involved in studying the mind?

1. behavioral experiments
2. physiological experiments

2

What is cognitive neuroscience?

-study of physiological basis of cognition
-understanding of nervous system + individual units that comprise that system

3

What are examples/methods of the behavioral approach?

-measures relationship between stimuli and behavior
-RT
-proportion of errors
-verbal protocols/self report

4

What are examples/methods of the physiological approach?

-measures relationship between physiology and behavior
-EEG/ERP
-heart rate, skin conductance etc.
-PET
-fMRI

5

What are the variables of the memory consolidation study?

independent:
group 1: learned words right before sleep
group 2: learned words long before sleep

dependent: memory (percent forgotten) 2 days later

6

What were the behavioral results of the memory consolidation ex.?

awake group showed higher percent of forgetting

7

What were the physiological results of the memory consolidation ex.?

-differential brain activity in the hippocampus
-increase in sleep group
-decrease in awake group

8

What did anatomists first believe the structure of the brain to be?

continuous nerve net

9

What did Camillo Golgi find in 1870 with better staining techniques?

structure of a neuron

10

What method did Santiago Ramon y Cajol use?

-Golgi's staining technique on tissue from brains of newborn animals

11

What was Ramon y Cajol's major idea?

neuron doctrine

12

What is the neuron doctrine?

-individual cells transmit signals in nervous system
-cells not continuous with other cells

13

What are Caja's 4 major findings?

1. synapses
2. neural circuits
3. receptors
4. specialized cells to create, receive + transmit info

14

dendrites

-multiple branches reaching from cell body
-receive info

15

cell body

-contains mechanisms to keep cell alive
-contains nucleus

16

myelin sheath

-fatty tissue
-electrical insulator
-facilitates propagation

17

nodes of ranvier

-gaps in myelin
-regenerates AP

18

synapse

-junction between nerve cells
-diffusion of NT

19

axon

-tube that transmits AP

20

What are microelectrodes?

-small shafts of conductive solution that pick up electrical signals

21

What are the 2 parts of a microelectrode?

1. recording electrode: recording tip inside nueron
2. reference electrode: located some distance away

22

What is resting potential?

-difference in potential between 2 electrodes when neuron is not firing
(-70 mV)

23

What is the voltage of a neuron when an AP fires?

+40mV

24

What is an action potential?

-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