Outline ways of studying the brain Flashcards
A01
fMRI (Functional Magnetic Resonance Imaging)
fMRI works by detecting blood flow in the brain
* It uses large magnets to detect oxygenised blood & show deoxygenised blood
* Brain areas that are more active, need more blood flow, this is oxygenised blood
* inactive or less active parts of the brain will show deoxygenated blood
* Active areas can then be compared with areas that are lower in activity and can be shown on the fMRI image
A03
Strength of FMRI
Non invasive
High spatial resolution
Strength
advantage of fMRI is that its non-invasive.
fMRI does not use radiation , virtually risk-free.
It produces images with high spatial resolution, depicting detail by the millimetre & providing clear picture of how brain activity is localised
spatial resolution refers to the smallest feature (or measurement) that a scanner can detect,its important feature of brain scanning techniques.
Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy.
A03
FMRI
expensive
Poor temporal resolution
Limitation
FMRi are expensive compared to other neuroimaging techniques & can only capture clear image if person stays still
* Poor temporal resolution as fMRI scans have a temporal resolution of 1-4 seconds which is worse than other techniques (e.g. EEG/ERP which have a temporal resolution of 1-10 milliseconds)
* FMRI can only measure blood flow in brain
fMRI scans do not provide a direct measure of neural activity. fMRI can only measure changes in blood flow thus its impossible to infer causation (at a neural level)
psychs unable to conclude whether brain region is associated with a particular function.
Temporal resolution refers to the accuracy of the scanner in relation of time: or how quickly the scanner can detect changes in brain activity
A01
ERP (Event-related Potential)-stimuli is presented directly
Event-Related Potentials (ERP) use similar equipment to EEG electrodes attached to the scalp.
electrical activity in the brain generated as result of stimuli.
Biopsychologists can compare normal wave patterns to the patterns that are caused by external stimuli.
Different wave patterns are generated in response to different stimuli.
- However, key difference is that a stimulus is presented to a p
(for example a picture/sound) & researcher looks for activity related to that stimulus. - however EEG is a recording of general brain activity usually linked to states such as sleep and arousal
A01
EEG (Electroencephalogram)
EEG (Electroencephalogram)
EEGS measure electrical activity within the brain via electrodes that are fixed on persons sclap using skull cap
Wave patterns are generated.
only)EEG have provided useful in studying stages of sleep & in diagnosis of epliepsy
A03
EEG & ERP
High temporal resolution
Non-invasive
Cheaper
Strength
- EEG & ERP are non-invasive.
- EEG and ERP do not use radiation, virtually risk-free.
- EEG &ERP are cheaper techniques in comparison with fMRI scanning thus more readily available.
EEG/ERPS technology has very high temporal resolution-can accurately detect brain activity at a resolution of single millisecond
shows usefulness of EEGS/ERPS
extra:
(only)EEG have provided useful in studying stages of sleep & in diagnosis of epliepsy
Temporal Resolution: An advantage of the EEG/ERP technique is that it has good temporal resolution: it takes readings every millisecond, meaning it can record the brain’s activity in real time as opposed to looking at a passive brain. This leads to an accurate measurement of electrical activity when undertaking a specific task.
A03
EEG /ERP
Poor spatial resolution
Limitations
EEG/ERP have poor spatial resolution.- meaning they do not show brain activity of specific areas, only overall brain wave activity.
EEGs/ERP only detect activity in superficial regions of brain.
EEGs/ERP are unable to provide info on what is happening in the deeper regions of brain
(such as the hypothalamus), making this technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm.
Spatial resolution refers to the smallest feature (or measurement) that a scanner can detect, important feature of brain scanning techniques.
Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy.
A01
Post Mortem Dissection
Post Mortem Dissection
Post mortem dissections is when a persons body, including their brain, is examined after they die
During the examination, brains are precisely cut
Researchers will examine & dissect brains of individuals who had suffered from trauma or mental illness & compare the brain with someone who had a neurotypical brain
This allows researchers to identify key function of specific parts of the brain
A03
Post Mortem Dissection
Strength
Post Mortem dissections have been fundamental in the development of understanding brains and how they function, including understanding localisation of function
The individual is not alive and so cannot experience any discomfort
A03
Post Mortem Dissection
Limitation
No brain activity can be measured as the research is conducted on a dead person
Brains could have been affected by the cause of death, effecting the results
It is difficult to compare the brain after death with the functioning prior to death, any relationship found would be correlational and not causal
