Ways of investigating the brain Flashcards
(13 cards)
1
Q
What are the 4 main techniques of studying the brain?
A
- fMRI scans
- EEGs
- ERPs
- post-mortem examinations
2
Q
How do fMRI scans work?
A
- detect changes in blood oxygenation & flow that occurs as a result of neural activity in specific areas of the brain
- when the brain is more active it consumes more oxygen to meet increased demand
- produces 3D images showing which parts of the brain are involved in particular mental processes
3
Q
What are the strengths of fMRI?
A
- doesn’t rely on the use of radiation like PET
- risk-free, non-invasive and straightforward
- produces images with high spatial resolution which provide a clear picture of how brain activity is localised
4
Q
What are the weaknesses of fMRI?
A
- expensive compared to other neuroimaging techniques
- clear image only captured if person stays completely still
- poor temporal resolution due to 5-second time lag behind image on the screen
- only measures blood flow in the brain and doesn’t take into account the activity of individual neurons making it difficult to to tell exactly what kind of brain activity is represented on the brain
5
Q
How do EEGs work?
A
- measures electrical activity in the brain through electrodes fixed onto the scalp using a skull cap
- scan recording represents brainwave patterns generated from the action of neurons which provides an overall account of brain activity
- often used by clinicians to indicate neurological abnormalities like tumours, epilepsy etc
6
Q
What are the strengths of EEGs?
A
- helped to diagnose conditions like epilepsy by random bursts of activity in the brain which are easily detected on screen
- contributed to our understanding of the sleep stages
- high temporal resolution allowing which allows accurate detection brain activity
7
Q
What are the weaknesses of EEGs?
A
- generalised nature of info received
- EEG signal not useful for pinpointing exact source of neural activity
- doesn’t allow researchers to distinguish between activities from different by adjacent locations
8
Q
How do ERPs work?
A
- all extraneous activity from original EEG recording is filtered leaving the responses related to performing a specific task
- ERPs is what remains - types of brainwaves triggered by particular events
9
Q
What are the strengths of ERPs?
A
- brings more specificity to measurement of neural processes
- high temporal res since it is derived from EEG measurements which has led to widespread use in measuring cognitive functions & deficits
- researchers have been able to identify different types of ERPs & describe the precise role of these in cognitive functioning
10
Q
What are the weaknesses of ERPs?
A
- lack of standardisation between different research studies making it difficult to confirm findings
- in order to establish pure data in ERP studies background noise & extraneous material must be completely eliminated which isn’t easy to achieve
11
Q
How do post-mortem exams work?
A
- involves the analysis of a person’s brain after their death
- those whose brains are subject to post-mortems are likely to have a rare disorder & have experienced unusual deficits in mental processes or behaviour
- areas of damage are examined after death to establish the likely cause of suffering experienced
- may also involve comparison with a neurotypical brain to determine the extent of differences
12
Q
What are the strengths of post-mortem exams?
A
- was vital in providing a foundation for early understanding of key processes in the brain
- Broca & Wernicke relied on post-mortem studies to establish links between language, brain & behaviour before neuroimaging existed
- improve medical knowledge & help generate hypotheses for further study
13
Q
What are the weaknesses of post-mortem exams?
A
- observed damage to the brain may not be linked to deficits but some other unrelated trauma or decay
- ethical issues of consent from the individuals before death is raised - they may not be able to provide informed consent
