Ways of Studying the Brain

Question 1

What are the 4 ways of studying the brain?

Answer 1

1. fMRI
2. EEG
3. ERP
4. Post-Mortem Examination

Question 2

What does fMRI stand for?

Answer 2

Functional Magnetic Resonance Imaging

Question 3

What does EEG stand for?

Answer 3

Electroencephalogram

Question 4

What does ERP stand for?

Answer 4

Event Related Potentials (ERP)

Question 5

What are fMRIs used for?

Answer 5

used to measure changes n brain activity, while a task is being performed

Question 6

How do fMRIs work?

Answer 6

1. measures changes in blood flow
2. when a task is being carried out specific areas of the brain becomes more active
3. increased activity = increased need for oxygen
4. blood flow is increased as oxygen is delivered in red blood cells
5. this change in blood flow allows researchers to map which areas of the brain are involved in a particular mental activity

Question 7

What are EEGs used for?

Answer 7

used to measure electrical activity in the brain

Question 8

What is the process of using an EEG?

Answer 8

1. electrodes placed on scalp can detect electrical activity in brain cells
2. when graphed over a period of time it produces an EEG image
3. this image can then be used to detect and diagnose various disorders that affect brain activity, e.g. epilepsy and Alzheimers

Question 9

What is an ERP?

Answer 9

very small voltage changes in the brain triggered by specific events; e.g. cognitive processing of stimulus - e.g. looking at a picture

Question 10

What is the process of using an ERP?

Answer 10

because it is very difficult to pick amongst all the other activity, so….

1. stimulus is presented many times in order to establish a response
2. these responses are then averaged together
3. it is then easy to filter out all extraneous neural activity not related to the stimulus, because it won’t occur consistently, WHERAS neural activity that is related to the stimulus, will occur consistently
4. therefore all extraneous neural activity can be ‘cancelled out’ and activity related to the stimulus is easily identifiable

Question 11

What is post-mortem examinations?

Answer 11

the examination of a brain after the person has died

Question 12

Why is post-mortem examinations used?

Answer 12

used to establish underlying causes of particular behaviour that was displayed whilst they were still alive

Question 13

How are post-mortem examinations carried out?

Answer 13

researchers look for brain abnormalities that are not present in control groups to explain atypical behaviour

Question 14

Give 2 examples of a post-mortem examination

Answer 14

1860s - Broca found lesions in an area of Tan’s left frontal lobe (Broca’s area)

reduced number of glial cells in people with depression

Question 15

Give 2 strengths of fMRIs

Answer 15

1. unlike other scanning techniques such as PET scans, it does not rely on the use of radiation
2. it has very good spatial resolution - meaning that it produces images that depict detail by the millimeter, making it possible to get a clear picture of how activity is localised in the brain

Question 16

Give 2 weakness of fMRIs

Answer 16

fMRIs can only measure blood flow, it cannot home in on the activity of individual neurons, and so it can be difficult to tell exactly what kind of activity is being shown on the screen. This means it is not a truly quantitative measure of mental activity in these areas of the brain

2. fMRI may overlook the interconnectivity of brain sites. By only focusing on brain sites receiving increased blood flow, it fails to account for the importance of brain sites connecting/communicating with each other.

Question 17

Give 2 strengths of EEGs

Answer 17

1. Non-invasive - No insertion of instruments unlike PET and no exposure to radiation – EEGs are virtually risk free and is avoidant of any danger to the brain itself.
2. Cheaper than fMRI thus making them more available – Psychologists can gather more data on the functioning of the human brain thus contributing to our understanding of different psychological phenomena.

Question 18

Give 2 weaknesses of EEGs

Answer 18

1. Not highly accurate – electrical activity detected in several regions of the brains simultaneously – Very hard to pinpoint exactly which area is producing this activity. therefore cannot distinguish differences in activity between 2 closely adjacent areas.
2. Uncomfortable – Hard for the patients as electrodes are attached to their head – Could result in an unrepresentative reading as the patients discomfort could trigger cognitive responses to the real time situation.

Question 19

Give 2 strengths of ERPs

Answer 19

1. ERPS provide a continuous measure of neural activity in response to a stimulus. Therefore, changes to the stimulus can be directly recorded: e.g. if a blue coloured slide turned green.
2. Derived from EEG – Excellent temporal resolution compared to fMRI – Much more specificity has led to their widespread use in the measurement of cognitive functions and deficits.

Question 20

Give 2 weaknesses of ERPs

Answer 20

1. ERPS only monitor electrical activity in outer layers of the brain, therefore, cannot reveal electrical activity in deeper brain sites.
2. Extraneous stimuli must be eliminated in order to collect pure data, the participant may react to background noise or a difference in temperature – For experiments where these variables can’t be controlled, it’s difficult to draw conclusions.

Question 21

Give 2 strengths of post-mortem examinations

Answer 21

1. Allow for detailed examinations and measurement of deep brain structures (e.g. the hypothalamus) not measurable by brain scans.
2. Highly applicable – Broca and Wernicke both relied on post mortem studies in establishing links between language, brain and behavior decades before neuroimaging ever became a possibility – Evidence has improved medical knowledge and less money can be used by the NHS on less efficient techniques which generates a positive impact on the economy.

Question 22

Give 2 weaknesses of post-mortem examinations

Answer 22

1. The issue of causation – The deficit a patient displays during their lifetime may not be linked to the deficits found in the brain, they may be the result of another illness – Psychologists are unable to conclude that the deficit is caused by the damage found in the brain. Various factors can act as confounding variables and might confuse findings/conclusions. For example, length of time between death and post-mortem, other damage caused to the brain either during death or as a result of disease, age at death, drugs given in months prior to death, etc.
2. Deceased people are not able to provide informed consent such as HM because of his lack of short term abilities – There will be problems with replicability because future ethical guidelines will be stricter.