Scanning techniques Flashcards
Fmri
a method used to measure brain activity while a person is performing a task. The FMRI detects radio waves from changing magnetic fields. This enables researches to detect which regions of the brain are rich in oxygen and thus are active.
EEG
a record of the tiny electrical impulses produced by the brains activity. By measuring chartertsics wave patterns the EEG can help diagnose certain conditions of the brain
Event related potentials
the electrophysiological response of the brain to a specific sensory cognitive or motor event can be isolated through statistical analysis of EEG data
Post mortem examinations
the brain is analysed after death to determine whether certain observed behaviours during th persons lifetime can be linked to structural abnormalities in the brain
fmri strength
Better than other scanning techiques such as pet. Does not use radiation so if used right is virtually risk free, non invasive and straightforward to use. It also produces images that have high spatial resoultion and providing a clear picture of how brain activity is localised. So from can safely provide a clear picture of the brain
Event related potentials strength
They have excellent temporal resolution especially when compared to neuroimaging techniques such as fmri. Therefore are used to measure cognitive functions and deficits such as allocation of attentional resources and the maintained of working memory
Event related potentials
limitation song
Limitation song one - to get pure data background noise and extraneous material must be completely eliminated.this is a problem as it may not always be easy to achieve
Event related potentials limitation
lack of standardisation in ERP mythology between different resect studies which makes it difficult to confirm findings.
Limitation fmri
is expensive compared to other neuroimaging techniques. It has poor temporal resolution as there is a 5 second time lag behind the image on screen and the initial firing of neural activity. This means fmri may not truly represent moment to moment brain activity
Post mortem examinations strength
was vital for providing a foundation of early understanding of key process in the brain. Used by Paul Broca and Karl wrnicke in establishing links between language brain and bahrviour. They were also used to study HM’s brain to identify areas of damage. This means post mortem counting to provide useful information
Limitation
causation is an issue as damage to teh brain might not be because of deficit but some other unrelated trauma or decay. Ethical issues HM lost his ability to form memories and was not able to provide such consent. This challenges the usefulness of post mortem studies in physiological research
apply it fmri
A strength of using the fMRI as a method of lie detection is that it is not invasive as no radioactive materials are used, and it does not require any special preparation from persons taking the test except removal of metal objects. However, this means it cannot be used in patients with metallic devices, like pacemakers. It is also an expensive measure of lie detection and is unsuitable for people who are claustrophobic (afraid of small places).
It also cannot be used with uncooperative people because the person must lie still.
