Ways of Studying Brain Flashcards
(13 cards)
how do fMRIs study the brain
(Functional Magnetic Resonance Imaging)
- measure blood flow in brain in when person performs a task
- increased demand for oxygen = causes increased blood flow = more active brain region
how do EEGs study the brain
(Electroencephalogram)
- measures electrical activity in the brain (electrodes placed on scalp)
- typical activity patterns include; alpha, beta, theta, delta & gamma waves
- signals = graphed and can be used to detect certain types of disorders (e.g. Alzheimer’s disease)
how do ERPs study the brain
(Event-Related Potentials)
- technique (statistical averaging) can demonstrate how processing is affected by specific stimuli
- waves occur after 100ms = cognitive
- waves occur within 100ms = sensory
how can the brain be studied through post mortem examination
- enables researchers to perform more detailed examination of anatomical structure of brain (usually on atypical indiviuals) e.g. Broca with Tan
= compare with neurotypical brain also
temporal resolution (how quickly changes detected) of EEGs, ERPs, and fMRIs
EEG/ERP = high (1-10ms)
fMRI = low (1-4s)
pros of fMRIs
+ non invasive
- do not use radiation/insertion of instruments directly into brain (unlike PETs) = virtually risk-free
+ fMRI = high (1-2mm) spatial resol.
= clear, detailed picture of brain activity
cons of fMRIs
do not display direct causation
- fMRI simply measure blood flow changes (no info on activity of individual neurons)
= not truly quantitative measure of mental activities in displayed brain areas
pros of EEGs
real-word usefulness
= used to study stages of sleep and diagnosis of conditions, e.g., epilepsy (random bursts of brain activity) or alzheimer’s
= inform understanding and clinical diagnosis
cons of EEGs
- poor spatial resol.
(superficial, only general regions)
= difficult to pinpoint sources of activity - not allow researchers to distinguish between activities originating from diff but neighboring locations
pros of ERPs
+ display causation
- determine how processing = affected by specific experimental manipulation/stimuli
- increased specificity to measurement of neural process (in comparison to EEGs)
cons of ERPs
methodology lacks standardisation
- between diff research studies = hard to confirm findings
- establish pure data = background noise and extraneous material must be completely eliminated
= not easy to achieve
pros of post mortem
+ more detailed brain examination
= not possible with less invasive methods, e.g. fMRIs
+ deepen understanding of certain disorders, e.g., SZPN
cons of post mortem
not always possible to obtain fully informed consent from prospective PM participant
- especially if ability to give consent = severely compromised by their disorder e.g. HM’s extreme amnesia meant only consent by proxy was possible
= limits ethics of PME to some extent
