Brain Investigation Techniques Flashcards
(19 cards)
What are 4 ways of investigating the brain
- Functional magnetic resonance imaging (fMRI)
- Electroencephalogram (EEG)
- Event-related potentials (ERPs)
- Post-mortem examinations
Which investigating technique is most likely to measure whole brain activity rather than specific areas of activity
EEG
Which investigating technique detects changes in blood oxygenation and flow that occur as a result of neural activity
FMRI
Which investigating technique uses a statistical averaging technique to remove extraneous scan data
ERP
What is post-mortem
-Analysis of a person’s brain after their death
-person is more likely yo have had a rare disorder or experienced unusual deficits in mental process or behaviour during their lifetime
What is an advantage of using EEGs over fMRIs
EEG have a high temporal resolution, whereas fMRIs have a poor temporal resolution
Which investigating technique is a useful diagnostic tool for epilepsy
EEGs
What is an advantage of using post-mortem over non-invasive techniques (fMRIs and EEGs)
Allows a more detailed examination of anatomical and neurochemical aspects of brain that wouldn’t be possible with non-invasive techniques
What are two limitations of using post-mortems
- Issues with causation- damage may not be linked to deficit under review but to some other trauma
- Ethical issues of consent from before death
What are two advantages of using fMRIs
-Produce images that have very high spatial resolution (1-2mm) and clear picture of how brain activity is localised
- non-invasive; no insertion of instruments into the body or harmful exposure to radiation
What are two disadvantages of fMRI’s
-poor temporal resolution (5-second time lag)
-only measure blood flow in the brain and cannot hone in on the activity of individual neurons
What is an fMRI
- measure changes in blood flow
- when the brain is more active it consumes more oxygen so their is increased blood flow
- fMRI can detect the different magnetic qualities that deoxygenated and oxygenated blood has, creating a 3D moving image
What is an EEG
- measure general activity in the brain via electrodes
- small electrical charges are detected by the electrodes that are graphed, which indicate level of activity
- the scan recording represents the brainwave patterns
What are 2 advantages of EEG
- high temporal resolution (every millisecond)
- useful in clinical diagnosis- has proved invaluable in diagnosis of epilepsy
What are 2 disadvantages of EEG
- poor spatial resolution, can only detect activity in superficial regions of the brain and not deeper regions such as hypothalamus and hippocampus
- not useful for pinpointing the exact source of neural activity
What is an ERP
-very small voltage changes in the brain that are triggered by specific events of stimuli
- achieved by isolating EEG data through statistical analysis
What are 2 advantages of ERP
- can measure the processing of stimuli even in the absence of a behavioural response
- they make it possible to monitoring ‘covertly’ without requiring the person to respond to them
What are 2 disadvantages of ERP
- background noise and extraneous material must be completely eliminated and this may not always be easy to achieve
- lack of standardisation in methodology makes it difficulty to confirm findings
What are 2 advantages of post mortem
- allows for more detailed examination of anatomical and neuron helical aspects of the brain that wouldn’t be possible with non-invasive treatments
- played a central part in early understanding of key processes in the brain
