Studying the brain Flashcards
How does an fMRI work
- measures changes in brain activity while a person performs a task
- uses magnetic field to measures changes in blood flow of a particular area in the brain becomes more active there is an increases demand for oxygen thus increasing blood flow
What are strengths of uding an fMRI
- non-invasive
- ethical
- accurate spatial resolution
Evaluate non-invasiveness as a strength of using an fMRI
- non invasive way of studying the brain
- unlike other techniques such PET scans which involve administration of a radioactive substance fMRI just measures changes in blood flow
- strength because fMRI is risk free and straightforward to use therefore a a useful way for investigating localisation
Evaluate ethics as a strength of using fMRIs?
- ethical way of studying the brain
- patients in MRI are likely to be in an appropriate mental state and able to give full informed consent
- strength as ppts brains will not be used in research without their consent
- As fMRI scans the living brain they have a high validity compared to post mortems
What are limitations of using an fMRI
- expensive
- biological reductionism
- poor temporal resolution
- doesnt establish cause and effect
Evaluate accurate spatial resolution as a strength of using fMRIs
- have a very accurate spatial resolution of 1-2 millimetres
- they can measure activity in the brain to 1-2mm which is more accurate than other techniques
- strentgh because theories based on research using fMRIs may be more valid due to the accuracy
Evaluate poor temporal resolution as a limitation of using fMRIs
- poor temoral resolution of 1-4 seconds
- fMRIS measure activity in the brain every 1-4 seconds which is less sensitive than other techniques
- limitation because theories based on research using fMRIs may lack validity due to the relative lack of accuracy
Evaluate expensive costs as a limtation of using an fMRI
- very expensive
- fMRI machines are costly and require specific trained operators. As the cost for each ppt is so high it often means research involving fMRI scanning has small sample sizes which make results difficult to generalise from
- limitation as fMRIs cant currently be used as a practical technique for creating strong theories about the brain
Evaluate biological reductionism as a limitation of using fMRIs
- limitation as it focuses on localised brain activity
- because of this the networked nature of the brain is overlooked. Its argues that the communication between brain regions is the most critical to mental function
- limitation as it ignores how the brain functions as a whole and is therefore biologically reductionist
What is an Electroencephalogram
(EEG)
- records electrical activity in the brain by placing electrodes onto the scalp to detect small electrical charges resulting from activity
What is an event related potential
measures brain activity in response to a stimulus using the same equipment as an EEG
What is a strength of EEGs and ERPs
- cheaper than fMRIs
-practical applications - accurate temporal resolution
- non invasive
Evaluate cheapness as a strength of EEGs and ERPs
- they are cheaper than fMRIs
- So they are more widely available to researchers and more ppts can be used in research. This means sample size is larger so results are easier to generalise to other people
- strength because researchers can use these techniques to generate well supported theories
Evaluate practical application as a strength of EEGs
- have practical applications in terms of clinical diagnosis
- EEGs can pick up on disturbed brain activity which is associated with epileptic seizures, this is helpful in the diagnosis of epilepsy. They have also contributed to our understanding of the stages involved in sleep
- strength because EEGs have proved valuable in diagnosis of many conditions
What is a limitation of using EEGs and ERPs
- Only reasonably accurate spatial resolution
Evaluated limited spatial resolution as a limitation of EEGs and ERPs
- they are only reasonably accurate
- both techniques measure brain activity via electrodes which may only pick up sufficiently strong voltage changes and not record activity deep in the brain
- limitation because theories based on research using these techniques may be limited due to lack of accuracy
Evaluate accurate temporal resolution as a strength of EEGs and ERPs
- EEGs measure activity in the brain to 1-10 milliseconds which is more accurate than other techniques
- strength because theories based on research using EEGs may be more valid
What is a post mortem
the analysis of the brain following death
What is a strength of using post mortems
more detailed than other techniques
Evaluate more detail as a strength of post mortems
- allow psychologists to study the brain in a detailed way
- they are invasive and enable researchers to examine deeper regions of the brain that may not be accessible during non-invasive techniques
- strength because the technique can further researchers’ understanding of the brain more than other techniques. Enhances overall understanding of the brain
What are limitations of post mortems
-ethics
- retrospective data
Evaluate ethical issues as a limitation of post mortems
- raise ethical issues
- they require the consent of parents before death but depending on their health ppts may not understand what theyre consenting to.
- limitation because patients brains may be used fir research without their consent
Evaluate the use of respective data as a limitation of post mortems
- they rely on retrospective data
- as the person is already dead the researcher is unable to follow up on anything that may arise from the post mortem concerning the link between brain abnormality and cognitive functioning
- limitation because researchers can only make assumptions on the relation between the brain and corresponding behaviours and therefore lacks experimental validity
