PSYC2020 Practice Questions - Wk1 Research Methods Flashcards
Terminology denoting same and other side?
Contralateral is the other side. Ipsilateral is the same side.
Difference between rostral and caudal?
Caudal is towards the tail, rostral towards the head (‘nostril’)
Difference between mid and para- sagittal?
Directly in mid line vs off centre
3 reference planes?
Sagittal, transverse (horizontal), and frontal
What is an oblique plane?
Any odd direction or plane
What do structure and function describe?
Morphology (how its made) and activity (what its doing), respectively
A CT scan which shows the brain structure and indicates a tumour is showing us what about the brain?
Morphology
An EEG showing abnormal brain activity indicative of a serizure is showing brain ___?
Activity
Example of structural research method
CT scan for brain tumour
Example of functional research method
EEG showing seizure brain activity
Example of highly invasive research method
Single cell recordings of neurons. Electrodes implanted into brain. Usually done on animals, sometimes on humans when undergoing surgery.
Is a PET scan invasive?
Moderately - inject radioactive isotopes.
Is EEG invasive?
No.
What does higher SR mean?
More precise observation of where something is in the brain. Spatial resolution
Two aspects of spatial resolution
Where something is exactly and differentiating 2 locations
Two aspects of temporal resolution
When did something occur, and how far apart did two things occur?
What are possible causal relationships between a correlation? 3
One thing causes the other, or a common underlying cause, or just coincidence
What is the key to determining causation?
If you take x away then y must stop
What is a problem with using fMRI studies to relate behaviours to brain region activity?
It’s correlational - does not mean that the activity caused the behaviour
What is the best way to determine causation between brain regions and behaviour?
Stimulation which interferes/disrupts a brain region that is necessary to perform the behaviour
How can you take away or disrupt a region of brain activity?
TMS - this allows causal inference!
What behavioural responses can be measured? 3
Reaction times
Detection thresholds
Stimulus discrimination
How do you measure startle response?
Electrodes on eye muscles
Why do we have a startle response?
Brain stem reflex for protection
How does the size of startle response tell us something about current psychological state? 1eg
Response will be bigger if you are already afraid (fear-potentiated startle). Eg measuring whether aversive stimulus is correctly paired/learned.
What does Electrodermal activity measure? How does it work?
Fight or flight response. Autonomic activity/emotional arousal.
Skin becomes a better conductor when sweat is released.
Types of physiological responses we can measure ? 6
Electrodermal activity startle response Pupilometry Heart rate Muscle tension Polygraph
What is an acquired brain injury?
Any brain damage after birth. Could be stroke, alcohol/drugs, TBI (traumatic brain injury)
what is one of the earliest examples of neuropsychological investigation into acquired brain injury?
Broca’s area (patient tan)
What process is Broca’s area implicated in?
Speech production. Patient tan, could only say tan.
What is a problem with acquired brain injury studies when trying to locate regions which cause behaviour?
They’re not very precise because they are injury specific and could take out a whole area.
What do lesion studies say about mice running a maze?
Their ability to complete maze is correlated with the amount of lesions, not the specific area. This shows the ability is not localised and involves integration of multiple areas.
What are some problems of lesioning areas of the brain? 4
Not 100% accurate
Neighbouring tissue damaged
Functions which belong to neighbouring tissue mis attributed
Sometimes portions remain (and some function)
What are three ways you can lesion the brain?
Aspiration lesion
Radio frequency cuts
Life cuts
In TDCS difference between anode and cathode?
Neurons under anode become depolarised and more likely to fire
Cathode hinders performance by hyperpolarising neurons
What type of disruption is TDCS especially good for?
Transient disruption, with low invasiveness
How can you produce virtual lesion of neurons?
Cryogenic block - probe is inserted and temporarily cools neurons so they stop firing
What’s the WADA test?
Testing where the speech area is lateralised using anaesthetics. Done prior to ablative surgery (for epilepsy)
What is a cryogenic block?
Neurons are virtually lesioned using cooling/
What is rTMS?
Repetitively giving magnetic pulses to produce a virtual lesion, prior to a task.
What effects does TMS cause? 2
Stimulation effects (motor or visual activation eg seeing a flash) Disruption effects (reveal timing information)
What does single TMS allow us to measure?
Temporal aspect ofwhen a brain area is used. By disrupting that area during a behaviour
What are two ways that TMS can be used?
Single TMS synchronised to disrupt a behaviour
rTMS to produce virtual lesion
What’s a problem with MEG measurements?
Great temporal resolution by measuring magnetic fields, but limited to the surface of brain. (No good for subcortical areas)
What does EEG measure on the scalp? And how is it messy? 2
Gross electrical activity.
- So it can be confused by muscle activity in the jaw and scalp
- sums up all events, action potentials, postsynaptic potentials
What EEG waveforms correspond to the following states of consciousness: Deep sleep, relaxed, focused
Delta (<4Hz)
Alpha (8-12Hz)
Beta (16-31Hz)
What is an ERP (event related potential)?
Subtracting average background signal to remove noise. This allows us to see small activity associated with a locked event.
Types of ERPs and the psychological process they represent? 4
N100 & P100 - selective attention
N200 - mismatch negativity (brain recognises stimulus deviates)
P300 attended stimulus registers
P400 unexpected stimulus surprise
Advantages (4)and disadvantages (3)of EEG?
Pros: - high temporal resolution - measure of activity - non-invasive: no drugs, tracers - relatively low cost Cons: - low spatial resolution - poor activity below superficial layers (cortex - gyri) - low SNR ratio means lots of trials and participants (time consuming)
What is an example where the research method can invoke a lot of fatigue in the participants?
EEG - need to prepare the device and then lots of successive trials to counter noise
4 methods of imaging the brain
PET - positron emission tomography
MRI - magnetic resonance imaging
DTI - diffusion tensor imaging
fMRI - functional
2 methods of recording activity in the brain
EEG & MEG (magneto-encephalography)
4 methods of disrupting
Drug block
Cryogenic block
Trans cranial Direct Current stimulation - TCDS
Transcranial magnetic stimulation - TMS
Broadly, what types of measures are correlational vs causative?
Imaging and activity recording are correlational. Disrupting activity causal.
How does PET work?
Radioactive tracer coupled to bio-active molecule
What is DTI (Diffusion Tensor Imaging)?
Measures density and motion of water along axon fibres. This shows us connections in the brain.
What does fMRI measure?
Changes in blood flow which is related to activity in the brain. Measuresoxygen - BOLD (blood oxygen level dependent contrast)
What is fMRI subtraction?
Removing (averaging out) a control image of the brain to find the target areas
4 advantages of fMRI?
- no tracers, better temporal and spatial res than PET
- no known health risks
- structural and functional info in one image
- 3D image of activity over whole brain
4 disadvantages of fMRI?
- low temporal resolution
- indirect measure of neuronal activity (BOLD proxy/correlation)
- 2-3 seconds to create image
- not causal
What are 4 research methods which are invasive?
ABI, Lesion studies, Cryogenic block, & PET (radioactive tracer)
What two research methods can provide structural info?
MRI and DTI
What 3 research methods have high spatial resolution?
MRI, DTI, fMRI
What 2 research methods have high temporal resolution?
MEG & EEG
What method measures autonomic nervous system activity?
Skin conductance response
Respectively, what do TMS, MEG, EEG, PET, MRI, DTI, fMRI measure?
Behaviour, magnetic, electric, metabolism, density, flow, oxygenation
What does TCDS measure?
Behaviour, it uses electricity but measures behavioural effects
Which methods would be correlational? And which are causal?
Correlational - recording associated activity & structural imaging
Causal - anything that stimulates or disrupts a region/activity
How long does fMRI take to register activity brain activity?
Peak 10s, through to 20s
