ways of studying the brain evaluation Flashcards
What is a strength for functional resonance imaging
Some key strength of fMRI is, unlike other scanning techniques such as PET, it does not rely on the US of radiation
If administered correctly it is virtually tisk free, non invasive and straightforward to use.
It all produces images that have very high spatial resolution, depicting detail by the millimetre, providing a clear picture of how brain gravity is localised.
This means that fMRI can safely provide a vkea4 image of brain activity
What is a limitation of fMRI
It is expensive compared to other neuroimaging techniques
It has poor temporal resolution because there is around a 5 second time lag behind the image kn screen and the initial firing of neuronal activity.
This means fMRI may not truly represent moment to moment brain activity
Whatvis a strength for EEG
EEG has been useful in studying the stages of sleep and in the diagnosis of conditions such as epilepsy a disorder characterised by random bursts of activity in the brain that easily be detected on screen
Unlike fMRI, EEG technology has extremely high temperature resolution.
Today’s EEG technology can accurately detect brain activity at a resolution of a single millisecond (and even less in some cases).
This shows the real world usefulness of techniques
What are the limitations of EEG
The main drawback of EEG lies in the generalises nature of the information received (that kf many thousands of neurons).
The EEG signal is also not useful for pinpointing the exact source of neural activity .
Therefore it does mot allow researchers to distinguish between activities originating in different but adjacent locations
What is a strength of event related potentials
The limitations of EEGare partly addressed through the use of ERPs.
These bring much more specificity to the measurement of neural processes that could be achieved using raw EEG data.
ERPs are derived from EEG measurements, they have except temporal resolution especially when compared to neuroimaging techniques such as fMRI
This means that ERPs are frequently used measure cognitive functions and deficits such as the allocation of attentional resources and the maintenance of working memory
What are the limitations for event-related potentials
Critics have pointed to a lack of standardisation in ERP methodology between different research audiences which makes it difficult to confirm findings
A further issue is that, in order to establish pure data in ERP studies, background “noise” and extraneous materials must be completed eliminated.
This is a problem because it may not always be easy to achieve
What are the strengths of post mortem examination
The evidence for post mortem examination was vital in providing a foundation for an early understanding of key processes in the brain.
Paul Broca and Karl Wernickle both relied on post mortem studies in establishing liks between language brain and behaviour decades before neuroimging eve became a possibility
Post mortem studies were also used to study HM ‘s brain to identify the areas of damage, which could then be associated with his memory deficits.
This means that post mortem continues to provide useful information
What is a limitation of post mortem examinations
Causation is an issue within these studies.
The observed damage to the brain may not be linked to te deficits under review but to some other unrelated trauma or decy.
Further problem is that post mortem studies raise ethical issues of consent from the individual before death
Participants may not be able to promote informed consent for example in the case of HM whilst his ability to form memories and was not able to provide consent - nevertheless post mortem research has been conducted on his brain.
This challenged the usefulness of post mortem studies in psychological research
