Biopsychology: Ways Of Studying The Brain

Question 1

Overview: fMRIs.

Answer 1

• Works by detecting changes in blood oxygenation and blood flow that indicate increases neural activity.
• People are asked to do tasks and the brain activity is observed.
• When a brain area is more active, it consumes more oxygen this increases amount of blood flow directed to the active area (haemodynamic response).
• Produces 3-dimentional images showing which particular mental process which is important for establishing localisation of function.

Question 2

Strength: fMRI Is Non-Invasive.

Answer 2

• fMRI is non-invasive.
• Unlike other scanning techniques (eg PET) fMRI does not rely on the use of radiation and is safe.
• This makes it an appropriate method to measure brain activity.

Question 3

Strength: fMRI Images With High Spatial Resolution.

Answer 3

• fMRI produces images with high spatial resolution.
• It can show detail by the millimetre.
• This means fMRI can provide a clear picture of how brain activity is localised.

Question 4

Limitation: fMRI Expensive.

Answer 4

• fMRI is expensive.
• fMRI is expensive compared to other techniques and can only capture an image if the person stays still.
• This limits the appropriateness of fMRI.

Question 5

Limitation: fMRI Has Poor Temporal Resolution.

Answer 5

• fMRI has poor temporal resolution.
• This is because there is a 5 second lag between initial neural activity and image.
• This means fMRI may not truly represent moment-to-moment brain activity.

Question 6

Overview: EEGs.

Answer 6

• Records changes in electrical activity using electrodes attached to the scalp.
• The scan recording represents the brain wave patterns that are generated from the action of millions of neurons (general), providing an overall account of brain activity.
• Often used as a diagnosis tool as unusual arrhythmic patterns may indicate neurological abnormalities e.g epilepsy.

Question 7

Strength: EEG Invaluable In Diagnosing Conditions.

Answer 7

• EEG is invaluable in diagnosing conditions.
• For example it has been used to identify epilepsy and also in understanding the stages of sleep.
• This shows that EEGs are an appropriate way to measure brain activity.

Question 8

Strength: EEG Has Extremely High Temporal Resolution.

Answer 8

• EEG has extremely high temporal resolution.
• EEGs can detect brain activity at a resolution of a single millisecond.
• This means that it is more able to represent moment-to-moment brain activity.

Question 9

Limitation: EEG General Information.

Answer 9

• EEG information is received from many thousands of neurons.
• The EEG produces a generalised signal from thousands of neurons this means it’s difficult to know the exact source of neural activity.
• Therefore EEG cannot distinguish between the activity of different but adjacent neurons.

Question 10

Limitation: EEGs Does Not Provide A Complete Of Brain Activity.

Answer 10

• EEGs do not provide a complete picture of brain activity.
• They only monitor electrical activity in outer layers of the brain.
• Therefore they cannot reveal electrical activity in deeper brain sites.

Question 11

Overviews ERPs.

Answer 11

• Records changes in electrical activity using electrodes attached to the scalp but uses a specific stimulus (sensory, cognitive or motor) to see where the activity is.
• Using a statistical averaging technique, all extraneous brain activity from the original EEG recording is filtered out leaving only those response that relate to a specific or task.
• Research has revealed many different forms of ERP and how these are linked to cognitive processes.

Question 12

Strength: ERPs Are Specific.

Answer 12

• ERPs are a very specific measurement of neural processes.
• They are more specific than what can be achieved using raw EEG data.
• This means that it is a better method of investigating the brain.

Question 13

Strength: ERPs Excellent Temporal Resolution.

Answer 13

• ERPs have excellent temporal resolution.
• ERPs can detect brain activity as resolution of a single millisecond.
• This means that it is more able to represent moment-to-moment brain activity.

Question 14

Limitation: ERPs Lacks Standardisation.

Answer 14

• ERPs lack standardisation in methodology between studies.
• This makes it difficult to confirm findings in studies involving ERPs.
• Therefore the reliability of the information regarding the brain’s structure and function is lowered.

Question 15

Limitation: ERPs Extraneous Things Must Be Eliminated.

Answer 15

• ERPs must have background noise and extraneous material must be completely eliminated.
• This may not always be easy to achieve.
• This limits the appropriateness of the method for investigating the brain.

Question 16

Overviews: Post-Mortems

Answer 16

• Examine abnormalities in the structure of the brain which try to explain psychological abnormalities that people have before death.
• May also compare with neurotypical (normal) brain in order to ascertain the extent of the difference.

Question 17

Strength: Post-Mortems Foundation For Understanding The Brain.

Answer 17

• Post-mortems provided the foundation for understanding the brain.
• Broca and Wernicke both relied on post-mortems studies.
• This shows that post-mortem studies have improved medical knowledge and helped to generate hypotheses for further study.

Question 18

Strength: Post-mortems Allow In-Depth Study.

Answer 18

• Post-mortems allow for in-depth study of the brain.
• Detailed examinations and measurements of deep brain structures for example hypothalamus that are not measurable by scans can occur.
• This provides us with knowledge of the brain that cannot be gained from less invasive options.

Question 19

Limitations: Post-Mortems Causation Issue.

Answer 19

• In post-mortems causation may be an issue.
• Observed damage in the brain may not be linked to the deficits under review but some other related to trauma or decay.
• This limits the appropriateness of the method.

Question 20

Limitations: Post-mortems Ethical Issues.

Answer 20

• Post-mortem studies raise ethical issues of consent.
• Before death, patients need to give informed consent , but there is a reason that psychologists want to investigate their brains in the first place.
• This meant that they may not be able to provide informed consent, for example HM.