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Flashcards in Methods Deck (49)
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1
Q

Scientific Method

A

Observation –> hypothesis –> predictions –> experiements

2
Q

Behavioral Approach

A

Measures of observable behavior and assumes that internal transformations or mental operations occur

i.e. Reaction times, task accuracy, task limittions, rating scales, time spent look at a stimulus, etc

3
Q

Cognitive Psychology

A

the study of mental acitivity as an information-processing problem

4
Q

Neuropsychological Approach

A

if a region of the brain is essential for some aspect of cognition, then damage to that region should affect performance on that aspect of cognition

5
Q

The Damaged Brain

A

vascular disorders, tumors, degenerative disorders, traumatic brain injury, epilepsy

6
Q

Vascular Disorders

A

angiography: a clinical imaging method used to evaluate the circulatory system

Cerebral Vascular Accidents: “stroke” occurs when blood flow to the brain is suddenly disrupted

7
Q

Tumors

A

a mass of tissue that grow abnormally and has no physiological function

i.e. brain lesions (can be a result of a tumor)

H.M.

8
Q

Degenerative Diseases

A

associated with both genetic aberrations and enviornmental agents

i.e. huntingtons disease, parkingson’s and alzheimers

9
Q

Traumatic Brain Injury

A

can result from either closed or open head injury

10
Q

Epilepsy

A

A condition characterized by excessive and abnormally patterned activity in the brain

H.M : had intractable epilapsy, had almost entire medial temporal lobe surgically removed

11
Q

H.M

A

had intractable epilepsy and had almost his entire medial temporal lobe removed surgically

resulted in anterograde amnesia (unable to form new memories) suggesting MTL critical for long term memory

He could still acquire new skills even though he couldn’t remember

12
Q

Difficulties working with Lesions

A
  1. often large
  2. dont stay within functionally-relevant boundaries
  3. there can be cortical plasticity/reorganization
  4. researchers are limited to a single “case study” because there may not be multiple individuals with similar lesions
13
Q

Dissociation

A

neuropsychology

can it answer: is this brain area necessary for this process?

14
Q

Single dissociation

A

A study in which two groups are each tested on two tasks, a between-group difference is apparent in only one task. The two groups are needed so that the participants performance can be compared with that of a control. Two tasks are necessary to examine whether a deficit is specific to a particular task or reflects a more general impairment.

15
Q

Example of single dissociation

A

Testin H.M on famous faces vs skill learning (drawing star from reflection)

16
Q

Disadvantages of single dissociation

A

limited in what it can truly tell us in terms of brain localization

17
Q

Double Dissociation

A

stronger representation that identifies whether two cognitive functions are independent of each other, something at a single association cannot do.

Group 1 is impaired on task A not B, group 2 is impaired on B not A. Performances are compared with a control group that had not impairments

18
Q

Example of double dissociation

A

parkinson’s patients - opposite results from H.M. and therfore form double dissociation

broca’s vs wernicke’s

19
Q

Methods to perturb neural function

A

Pharmacological Studies

Transcranial Magnetic Stimulation (TMS)

20
Q

Pharmacological Studies

A

may involve the administration of agonist drugs, those that have similar structure to a neurotransmitter and mimic its action, or antagonist drugs, those that bind to receptors and block or dempen neurotransmission.

21
Q

Example of pharmacological study

A

administration of dopamine to study its effect on decision-making when a monetary reward was available

22
Q

Drawbacks to pharmacological studies

A

lack of specificity due to injection into the bloodstream

23
Q

TMS

A

Transcranial Magnetic Stimulation

A method to non-invasively producing focal stimulation of the human brain. Interupts firing

24
Q

Advantages and disadvantages of TMS

A

Advantages: direct disruption of neural tissue and another good way to discern whether or not a brain region is necessary

Disadvantages: poor spatial resolution, small sample size and no way to interpret a null result

25
Q

CAT

A

computed tomography

Important for structural imaging of neurological damage in patients

26
Q

MRI

A

Magnetic Resonance Imaging

Provides high resolution images of soft tissue by exploiting the magnetic properties of atoms that make up organic tissue.

Radio waves cause atoms (mostly hydrogen) in the body to move out of their natural random positions and into line with the magnetic fields –> after the field pulse stops, atoms move back into normal positions and emit radio waves as they do so

27
Q

DTI

A

diffusion tensor imaging

performed with an MRI scanner. Offers information about anatomical connectivity between regions

28
Q

Methods for studying neural function

A

Event-related Potential (ERP)

Electroencephalography (EEG)

Positron Emission Tomograhy (PET)

Functional Magnetic Resonance Imaging (fMRI)

29
Q

EEG

A

non-invasive electrodes that are placed on the scalp and measure electrical potentials produced by neurons

30
Q

ERP

A

Tends to relect the brain’s global electrical activity

Measures EEG response –> amplified –> averaged (give average waveform over time)

Waveforms are traditionally plotted with positive peaks downward and negative peaks upward

31
Q

Time-frequency Analysis in ERP

A

refers to the fact that amplitude of a wave in different frequency regions varies over the course of processing

32
Q

components involved in ERP

A

Lantecy, direction, amplitude, topographical distribution, and polarity (N or P followed by a # depiciting latency in ms)

33
Q

Latency

A

how long after the stimulus is presented

34
Q

Direction

A

is the wave peak positive or negative?

35
Q

amplitude

A

the strength of the voltage change

36
Q

topographical distribution

A

fronal, parietal, occipital, temporal

37
Q

advantages vs disadvantages of ERP

A

Advantages: excellent temporal resolution; direct measure of neural activity; event-related neural response

Disadvantages: poor spatial resolution

38
Q

Positron Emission Tomography

A

(PET)

a small dose of a chemical (radionuclide) used to label glucose is injected into a patient –> the radionuclide emits positrons –> machine will rotate around a patients head to detect the positron emissions given off by the radionuclide

Used to examine brain function: brain regions will uptake more of the labeled glucose when active during a cognitive task; must be done in the block design

39
Q

fMRI

A

Using radio waves the fMRI measures increases in blood flow in active parts of the brain. The detectors measure the ratio of ozygenated to deoxygenated hemoglobin (blood oxygen level-dependent/BOLD)

Uses subtractive logic – treats one activity as a baselind and subtracts it from the other, to get rid of all the activity the two conditions have in common

40
Q

Block Design

A

fMRI

Must perform tasks in blocks of at least 30 sec, average across the trials in every block

41
Q

Block Design disadvantages

A

Disadvantage: cannot sort by performance (i.e. words that are later remembered vs words that are later forgotton)

Pure insertion assumption

42
Q

Pure Insertion Assumption

A

If a control task requires stage 1 and 2 of processing and experimental task requires stage 1, 2, and 3, we assume that the 3rd stage doesn’t alter the other stages

43
Q

Event Related Design

A

measures blood flow response associated with individual trials rather than for a block of trials

Dm Effect: difference in response based on memory (what regions are more active during encoding of items later remembered than during encoding of items later forgotten)

Subsequent memory = remembered - forgotten

44
Q

Advantages and Disadvantages of fMRI

A

Advantages: Measure magnetic properties of blood; temporal resolution = 2-3 secs; spatial resolution = 2-3mm; trials can be blocked/randomized

Disadvantages: poor temporal (time) resolution (seconds); results dependent on task and baseline (subtractive logic + pure-insertion problem); indirect measure of neural activity

45
Q

Diffusion Tensor Imaging

A

a structural scar acquired with an MRI

Gives information about white matter tracts that for the connectivity between regions

46
Q

Simulation

A

An imitation, a reproduction of behavior in an alternative medium (i.e. computers)

47
Q

Dependent Variable

A

what you are measuring

48
Q

Independent Variable

A

The variable that you are altering, with the expectation that it will have some effect on the dependent variable

49
Q

Lesions Studies vs Neuroimaging

A