Evaluation of ways of investigating the brain Flashcards
What are the strengths of fMRI’s?
Unlike PET scans does not rely on radiation
If used correctly - virtually risk free, non invasive and straightforward
Images are of a high spatial resolution providing clear picture of localisation
What are the weaknesses of fMRI’s?
Expensive compared to other techniques and relys on the person staying still
Low temporal resolution as there is a five second lag on screen and neural activity
It can only measure blood flow in the brain not activity of individual neurons so difficult to tell what kind of brain activity is on screen
What are the strengths of an EEG?
Invaluable to the diagnosis of conditions such as epilepsy as random bursts of activity in the brain can be easily detected
Helps understand stages involved in sleep
High temporal resolution - today can accurately detect brain activity at a resolution of a single millisecond
What are the weaknesses of the EEG?
The generalised nature of the information received
EEG signal is not useful for pinpointing the exact source of neural activity and doesn’t allow researchers to distinguish between activities originating in different but adjacent locations
What are the strengths of ERP’s?
Limitations of EEG addressed by ERP’s
Much more specific in measure of neural processes
Excellent temporal resolution - used in measurement of cognitive functions
Many different types and all have precise roles in cognitive functioning
What are the weaknesses of ERP’s?
There is a lack of standardisation in the use of ERP methodology between studies
In order to establish pure data in ERP studies background noise and extraneous materials must be completely eliminated
What are the strengths of post mortems?
Vital in establishing early processes in the brain e.g. Broca and Wernicke relied on them to make links between language brain and behaviour
They improve our medical knowledge
What are the weaknesses of post mortems?
Observed damage to the brain may not be linked with deficits seen but some other trauma
Raise ethical issues such as consent - patients may not be able to give informed consent as a result of damage to the brain e.g. patient HM
What is a possible use of fMRI’s?
Supporters suggest it is the perfect tool for detecting truthfulness as it is able to see inside the brain. It is argued that the analysis of neural blood flow is preferable to tracking peripheral measures such as pulse and GSR that are measured by traditional lie detectors and polygraph machines
