ways of studying the brain Flashcards
outline fMRI
fMRI uses magnetic field and radio waves to monitor blood flow;
* it measures the change in the energy released by haemoglobin, reflecting activity of the
brain (oxygen consumption) to give a moving picture of the brain;
* activity in regions of interest can be compared during a base line task and during a specific
activity
no radiation/non invasive
One strength of fMRI is that it is a non-invasive method of studying the brain.
E Unlike other techniques such as PET scans which involve the administration of a radioactive
substance to the body, fMRI just measures changes in blood flow.
E This is a strength because if an fMRI is carried out correctly it is virtually risk-free, non-invasive
and straightforward to use and is therefore a useful method for investigating localisation of
function and other brain activity.
its expensive
A limitation of using fMRI to study the brain is that it is very expensive.
E The fMRI machines are very costly and require specially trained operators. As the cost for each
participant is so high, it often means research involving fMRI scanning has small sample sizes
which makes the results of any such studies difficult to generalise from.
E This is a limitation of fMRI because it currently cannot be used as a practical technique for
creating strong theories about the function of the brain.
outline eeg
Electrodes are put on the scalp and detect neuronal activity directly below where they are placed; differing numbers of electrodes can be used depending on focus of the research.
outline ERPs
Electrodes are put on the scalp and detect neuronal activity (directly below where they are placed) in response to a stimulus introduced by the researcher.
cheaper than fmri
A strength of using EEGs/ERPs to study the brain is that they are cheaper than fMRI scanning.
E They are therefore more widely available to researchers and more participants can be used in research because the cost per participant is not as high. This means that the sample size in such research is often larger and so the results are easier to generalise to other people.
E This is a strength because researchers can use these techniques to generate well-supported
theories.
only reasonably accurate
A limitation of using EEGs/ERPs to study the brain is that they are only reasonably accurate at
measuring activity in the brain.
E Both techniques measure brain activity via electrodes which may only pick up sufficiently strong voltage changes and not record activity deep in the brain. Other techniques e.g. fMRI
scans may therefore be more effective at studying brain activity.
E This is a limitation because theories based on research using these techniques may be limited due to the lack of accuracy of the procedure
outline post mortems
The brain is examined after death to try and correlate structural abnormalities/damage to behaviour
more detailed than other techniques
A strength of post-mortem examinations is that they allow psychologists to study the brain in a very detailed way.
E Post-mortem studies are invasive and enable researchers to examine deeper regions of the brain such as the hypothalamus that may not be as accessible if using a non-invasive technique such as an fMRI.
E This is a strength because the technique can further a researcher’s understanding of the brain more than using other techniques alone. This enhances overall understanding of the brain and furthers scientific progress
ethical issues
A limitation of using post-mortem examinations is that they raise ethical issues.
E Post-mortems require the consent of the patient before death and depending on their health, participants may not be able to fully understand what they are consenting to. One example of this is patient HM who lost his ability to form memories and was not able to consent, however
an examination was still conducted on his brain.
E This is a limitation because participant’s brains may be being used for research without their informed consent.
