Psychological Methods and Inferences

Question 1

What is epistemology?

Answer 1

Philosophical study of how we know things, difference between beliefs and opinions
We get this knowledge from authorities, logic and through observations/evidence

Question 2

What are deductions?

Answer 2

Evidence based
Premise A + Premise B = conclusion
If premises are true, the conclusion will be true
If the premise isn’t true, neither is the conclusion

Question 3

What are inductions?

Answer 3

Evidence based
Premise A + Premise B + Premise C = conclusion
The more premises you find, the more probable the conclusion, conclusion will never be true, only probable.

Question 4

What is inferential reasoning?

Answer 4

Goes against verification
Inferential reasoning is the action of coming up with a conclusion while the method is called induction.
Observations lead us to infer theories of the world

Question 5

Why doesn’t verificationism work? What is it?

Answer 5

Many verifications doesn’t mean the theory is true
Seek evidence which proves our theory
There may be plenty of evidence but one bit of contradictory evidence could disprove the theory
Many verifications doesn’t mean the theory is true

Question 6

What is the difference between deductions and inductions?

Answer 6

Deductions: tests an existing theories
Inductions: develops a theory

Question 7

What is the difference between low and high spatial resolution images?

Answer 7

High resolution image has more pixels than low resolution, these are for 2D images
MRI (and other brain scans) pixels are called voxel as it uses 3D images

Question 8

What is falsificationism?

Answer 8

Find a reason why something can be wrong.
If we find one contradictory observation, then we are certain of this conclusion
This should be the preffered method of scientists
Seek evidence to disprove our theory and use a better theory which can’t be disproved

Question 9

How could you test reaction time?

Answer 9

Flash a light at one end of the bar
Ps should press the button as soon as they see the yellow dot. One bar was longer than the other bar, but this was an illusion. Reaction time was longer if they thought the bar was longer.

Question 10

What is temporal resolution?

Answer 10

More samples to detect the signal, in high resolutions you can have more samples than low resolution

Question 11

What is an EEG?

Answer 11

Electroencephalography

Tissue in our brain conduct electrical currents produced by synaptic activity
Spatial resolution limited
Electrodes embedded in a plastic cap. Placed onto scalp
Greater temporal resolution
Recordings from both sulci and gyari (parts of brain)

Question 12

How does action potential work?

Answer 12

Dendrites, Cell body and Axon
Input is dendrite
Cell body makes decisions to activate neuron or not
Sends signals through axons
More active neuron if there is more action potential

Question 13

What are the frequency bands in sleep?

Answer 13

Lowest frequency to highest:
Delta (as low as 0.5Hz)
Theta
Alpha
Beta
Gamma (up to 100Hz)
Faster Hz = Higher the frequency
Delta: deep sleep
Beta: awake
Gamma: using cognitive processes

Question 14

What are Event Related Potentials?

Answer 14

Use EEGs
Activity in brain is generated as a result of the event
Shows waveforms after stimulus, waveforms differ depending on the cognitive condition

Question 15

What did the Nignam, Hoffman and Simsons study in 1992 find?

Answer 15

Right hemisphere is more important because left hemisphere showed no difference between words and pictures
Used ERP
ERP greater for anomalous sentence types

Question 16

What are MEGs?

Answer 16

Magnetoencephalography
Electrical voltages (by neuron’s interacting) produce magnetic fields, MEGs record these magnetic fields
MEG recordings mainly come from the sulci unlike EEGs which pick up both sulci and gyri

Question 17

What are MRIs?

Answer 17

Magnetic Resonance Imaging
Head is placed in a magnetic field
Radio waves in the MRI cause the nuclei of the hydrogen atom to change position, as nuclei change back into original position, they emit their own radio waves which the scanner picks up
Hydrogen atoms change in a way that depends on the type of tissue they are in

Question 18

What are Functional Magnetic Resonance Imaging?

Answer 18

Blood flow increases in active parts of the brain
Works the same as an MRI
Focuses on deoxygenated blood however, different to MRI which focuses on oxygenated blood.
Deoxygenated blood is weakly magnetic
Blood Oxygen Level Dependant= ratio of oxygenated and deoxygenated blood
Increase in this ratio around the active regions of the brain
Low temporal resolution

Question 19

What are EEG artifacts?

Answer 19

Physiological: eye blinks/eye movement
Extraphysiological: electrical activity that comes from outside of the body, such as equipment

Question 20

What is CT?

Answer 20

Computerized tomography
First method to look into the human brain
20th century
Constructs 3D perspective of brain from a series of thinly sliced 2D images
Gave scientists precision, so they could understand lesion-behaviour relationships
Exposed to radiation which is a risk for the patient

Question 21

What is DTI?

Answer 21

Diffusion Tensor Imaging
Performed with MRI scanner
measures white matter pathways in the brain
Gives information on the anatomical connectivity between regions

Question 22

Which has greater spatial resolution MRIs or CTs?

Answer 22

MRIs
Density of protons is greater in grey matter than white matter

Question 23

What are some Invasive methods?

Answer 23

ECoG (electrocorticography) electrodes placed on the brain, the activity of the populations of neurons is recorded. Identify the location of the abnormal brain activity.
For patients going into neurosurgery
Greater spatial resolution

Question 24

What is a PET scan?

Answer 24

Position Emission Tomography
Radioactive substance injected into blood
This distributes to the brain
More neural activity = more radioaction
The injection is in the form of water, it’s an isotope, the nuclei rapidly decays and emits positron. Collision of two positrons create a gamma ray, the PET scan is a gamma ray detector.
It’s how we find out about Alzheimer’s
Low temporal resolution
Gains information on blood flow, metabolism and oxygen
Exposure to radiation which is bad for patients

Question 25

What’s a block design and an event related design?

Answer 25

Block designs are used in PET scans
The stimuli is shown in blocks

Event Related designs are used in FMRIs
The stimuli are interspersed with one another

Question 26

What is a Magnetic Resonance Spectroscopy?

Answer 26

Use MRIs to measure other properties of the brain tissue
Gives information on the chemical composition of the tissue