Pscyhological Methods and Inferences

Question 1

What is epistemology

Answer 1

Philosophical study of how we know things.

Basis for belief:
- authority such as “mum told me”
- logic such as cogito ergo sum (I think, therefore I am)
- observation/evidence based research

Question 2

What is deduction?

Answer 2

Process of elimination - as long as the premises are true, the conclusions will be true

Valid arguments do not guarantee truth conditions

testing an existing theory

Question 3

What is induction?

Answer 3

Method of reasoning where individual facts are used to give a general rule or conclusion

conclusions from induction may be true, but are not guaranteed

developing a theory

Question 4

what is inference?

Answer 4

the act of coming up with the conclusion based on evidence/observations

Question 5

What is verificationism

Answer 5

Seeking out evidence that agrees with our theory, of which there may be plenty

Question 6

why does verificationism not work?

Answer 6

a single piece of contradictory evidence could disprove theory

therefore, we should seek to disprove theories in order to make better ones - use CRITICAL perspective

e.g., “my car starts every day, therefore it is going to start tomorrow”

Question 7

What is falsification?

Answer 7

testing theories by trying to falsify (disprove) them

good theory = makes it clear what evidence would falsify it

bad theory = not falsifiable, e.g., ‘there is a Loch Ness monster’

Question 8

2 examples of neuroscience methods

Answer 8

• Reaction time
• Neuroimaging

Question 9

what are neuroscience methods for?

Answer 9

• help identify how cognitive algorithms are implemented in neural tissue
• help rule out certain algorithmic theories of cognitive function

Question 10

Robertson and Kim (1999) - Reaction Time Study

Answer 10

Flash prime at one end of line, then target at other end.

task: detect yellow target as quickly as possible

optical illusion used to make one line look longer than the other. when experiment was done on “longer” line, reaction time was increased

therefore, brain moves attention in an internally constructed world, rather than on physical features alone

Question 11

What is spatial resolution

Answer 11

Number of pixels (2D) or voxels (3D)

or

measure of the smallest object

Question 12

What is temporal resolution

Answer 12

Ability to distinguish between events that are close together

or

ability to detect changes over time

Question 13

Hemodynamic techniques

Answer 13

Positron emission tomography (PET)

Functional magnetic resonance imaging (fMRI)

• excellent spatial resolution
• poor temporal resolution

Question 14

Electro-magnetic techniques

Answer 14

Electroencephalography (EEG)

MRI

Magneto-encephalography (MEG)

• poor spatial resolution
• excellent temporal resolution

Question 15

what is the action potential

Answer 15

rapid change in voltage across a cell membrane, caused by a shift of the ions inside and outside of the cell

Question 16

how can we analyse EEG data

Answer 16

Time domain

Frequency domain

Question 17

What are event related potentials (ERPs)

Answer 17

fluctuation of the brain’s electrical field generated by neural activity, induced by stimulus

Brain shows reliable waveform after a stimulus

these waveforms differ based on the cognitive function

can determine how early functions start

Question 18

EEG artefacts

Answer 18

EEGs are affected by artefacts:

• physiological (e.g., eye blinks, movements, muscle, movement, sweat, cariogenic)
• extraphysiological (e.g, 50Hz UK mains is ambient electrical supply

Question 19

What is Magnetoencephalography

Answer 19

similar to EEG but records magnetic fluctuations around the head

the electrical currents associated with brain activity create magnetic currents

Question 20

What is MRI

Answer 20

When placed in strong magnetic field, hydrogen atoms respond to magnetic pulses in a way that depends on the type of tissue they are in, creating differences on the image

Question 21

what is fMRI

Answer 21

blood oxygen level dependent (BOLD)

• as brain area is active, cells in that area use more resources
• in response, blood oxygenation changes locally
• signal is very slow (low temporal resolution)

Question 22

what is a raster plot?

Answer 22

a visualisation technique of neural activity

Question 23

In what way is MEG better than EEG?

Answer 23

MEG signals only minimally distort magnetic fields as they pass through the brain, skull, and scalp.

Therefore, it is much easier to localise the source of a MEG signal compared to an EEG signal

Question 24

In what way is the EEG better than MEG

Answer 24

MEG is more expensive because the magnetic fields generated by the brain are very weak

Question 25

What is ECoG?

Answer 25

measures electrical activity in the brain, where the electrodes sit directly on the brain

Question 26

How does PET work?

Answer 26

• tracer isotope (in the form of water) injected into participants bloodstream while engaging in a cognitive task
• oxygen nuclei rapidly decay, emitting positrons
• collision of positron with electron creates two photons (gamma rays)
• the PET scan determines where this collision took place

Question 27

what is the BOLD effect, referring to fMRI?

Answer 27

• Blood oxygen level dependent effect
• fMRI detectors measure the ratio of oxygenated to deoxygenated haemoglobin
• this value is the BOLD effect

Question 28

what is the difference between block design and event related design

Answer 28

Block design = researcher integrates the recorded neural activity over a “block” of time during which the participant performs multiple trials of the same type

ERD = BOLD response links to specific events

Question 29

what is multivoxel pattern analysis (MVPA)

Answer 29

pattern clarification algorithm in which researcher identifies patterns of neural activity that are consistently present for an event/stimulus etc

Question 30

what is MRS? (magnetic resonance spectroscopy)

Answer 30

uses MRI machine to obtain chemical compositions of tissues, rather than anatomical information

Question 31

what is a connectivity map/connectome and what do they do?

Answer 31

visualisation of connections within the brain

capture correlated patterns of activity between different brain regions

Question 32

what are the 4 steps of constructing a brain network?

Answer 32

1) define network nodes
2) measure correlation between all possible pairs of nodes
3) generate association matrix
4) visualise correlations in connectivity map