Ways of Studying Brain Flashcards
Identify functional magnetic resonance imaging (FMRI)
- identify changes in levels of o2 in blood that occurs due to brain damage activity in specific areas
- high activity in brain leads to more oxygen being used so there is an increase of blood flow
- produces 3D image known as activation MAP
- used to identify which specific parts of brain are active in particular mental processes showing localisation
Why’s is FMRI safer technique to measure brain activity?
- non invasive doesn’t use radiation to identify differences in brain area
- unlike use of PET scans which uses radiation therefore FMRI more appr tech to use that could reduce risk of potential harm to I
What’s second evaluation for FMRI
P - has higher spatial resolution than EEG and ERP which is an important feature of brain scans as can accurately identify specific brain areas
E - depicting detail by mm and providing clear image of how brain is localised
E - however has poorer temporal solution as there is around 5 s time lag behind image on screen and initial firing of neuronal activity
L - fmris may not truly represent movement to movement brain activity
How does EEG’S work? electroencephalogram
- brain scanning technique works by placing electrodes placed on scalp using a skull cap
- detect elec changes from brain cell activity
- graph created to show general brain activity types of waves
- used to diagnose conditions such as brain tumours and epilepsy
Give a strength of EEG’s
P - high in temp resolution
E - enables R to take real time recording of brain activity rather than still image of brain as is case of fmris on post mortems
E - R can gain more accurate measure of brain activity in particular task
L - therefore providing greater insight into process of brain such as activity during sleep increasing val as a way of studying brain
Give a limitation of EEG
P - low in spatial resolution can only provide information on general activity in brain
E - cannot pinpoint exact source of neural activity that involved in bh
E - unlike use of ERP’s which enable R to identify specific brain activity in a particular task
L - therefore findings may be less valuable in dev understanding by using alternative ways of scanning brain such as ERP’s
How do ERPS’s work?
- like EEG’s place extrodes on scalp
- ERP shows specific brain activity unlike EEG
- stimulus is presented to I many times and brain activity measured in same way of EEG
- all extraneous brain activity from original EEG filtered out leaving only those responses that link presentation of stimulus/task
- what remains once extraneous variables filtered out are event related potentials - types of brain wave triggered by particular event
what’s :) of ERPS event related potentials
P - high temporal solution especially when compared to fmri
E - ERP’S can identify brain activity every millisecond so R can see brain activity in real time
E/L - ERP’s have poorer resolution than fmri as only detect brain activity in areas rather than studying brain for range of brain processes
Outline process of post mortems
- brain of a dead patient is examined and dissected to see if any physical/structural abnormalities
- compare with healthy brain/control group that does not show this mental process
- mainly used on people who have rare/disorder/defects
What’s a strength of post mortems?
P - only invasive way to study brain which means possible to get more detailed examination of brain
E - than be possible through solely using brain scanning techniques such as ERP’s and EEG’s
E - example meant R’s have been to study deeper areas of brain such as hypothalamus helped brain functioning in many diff bhs
what’s a weakness of post mortems?
P - hard to establish cause and effect as many confounding variables which cannot be easily controlled such as how long person had particular disorder age time death
E - limits IV of findings in these studies therefore appropriateness of using post-mortems
Explain the diff bw spatial resolution and temporal resolution
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