Brain scanning techniques

Question 1

fMRI

Answer 1

Functional Magnetic Resonance Imaging.

oxygen, task

Question 2

fMRI 2

Answer 2

• measures brain activity while a task is performed.
• uses MRI technology (detecting radio waves from changing magnetic fields)
• enables researchers to detect which regions are rich in oxygen (active) when involved in a particular mental activity.

part of the brain becomes more active, oxygen demand increases, increased blood flow to the brain, perceive areas activated by certain stimulus.

Question 3

Pros of fMRI

Answer 3

• non invasive- no harmful radiation/ invasion with tools.
• objective/ reliable measure of psychological processes. useful in investigating psychological phenomena not present in verbal report.

Question 4

Cons of fMRI

Answer 4

• not direct measure of neural activity in the brain. Not quantitative.
• ignores networked nature of brain- focuses on localisation.

Question 5

EEG

Answer 5

Electroencephalogram.

Question 6

EEG 2

Answer 6

• Measures electrical activity in the brain.
• electrodes placed on scalp detect small ECs from activity of brain cells.
• electrical signals graphed = EEG

Question 7

Uses of EEGs

Answer 7

• To detect types of brain disorders (eg. epilepsy) or to diagnose disorders that influence brain activity (eg. Alzheimer’s)- from spikes of slowing of brain electricity.

Question 8

Pros of EEG

Answer 8

• Records brain activity in real time, not a still image. More accurate measurement.
• useful in clinical diagnosis (epilepsy in someone experiencing seizures)

Question 9

Cons of EEG

Answer 9

• cannot reveal deeper processes such as the hypothalamus (reaches superficial regions). Electrodes in non humans to achieve this = unethical.
• activity picked up by neighbouring electrodes- cannot pinpoint exact source. Cannot differentiate between close areas.

Question 10

ERPs

Answer 10

Event- related potentials

In it’s raw form EEG is a general measure of brain activity- contained within the data is useful info about sensory, cognitive and motor events.
Isolates these responses through statistical averaging technique- where all activity filtered to leave responses relative to a stimulus.

Question 11

ERP Pros

Answer 11

• addresses limitations of EEG- specificity of measurement of neural processes.
• derived from EEG measures = high temporal resolution, led to widespread use in measurement of cognitive functions and deficits.

Question 12

ERP Cons

Answer 12

• lack of standardisation in ERP methodology between research studies, difficult to conform findings.
• background noise and extraneous material must be completely eradicated, may be challenging

Question 13

Post mortem examination

Answer 13

• involves analysis of the brain following death- likely to be those who have a rare disorder and have experienced unusual deficits in mental processes or behaviour during life.
• areas of damage are examined to establish likely cause of the personal affliction.
• may involve comparison with neurotypical brain in order to ascertain the extent of difference.

Question 14

Pros of post-mortem

Answer 14

• vital in providing a foundation for early understanding of key processes in the brain- Broca and Wernicke (before neuroimaging was possible)

Question 15

Cons of post-mortem