Functional Magnetic Resonance Imaging (fMRI) uses radio waves to form changing magnetic fields. Detects changes in blood oxygenation. More active areas of the brain use more oxygen and show up on the scans when in use
Strengths of fMRI:
doesn’t rely on the use of radiation
If administered correctly it is virtually risk-free
non-invasive and straightforward to use
produces images that have very high spatial resolution, providing a clear picture of how brain activity is localised
Limitations of fMRI:
expensive compared to other techniques
can only capture a clear image if the person stays perfectly still
has poor temporal resolution due to a 5-second-time lag behind the image on screen and the initial firing of neural activity
can only measure blood flow, not the activity of individual neurons
Electroencephalogram (EEG) records general brain wave activity by recording tiny electrical impulses produced by the brain
EEG's are used to diagnose epilepsy, tumours and sleep disorders
Strengths of EEG:
important for diagnosis of conditions because random activity bursts are easy to identify
Contributed to our understanding of sleep
high temporal resolution
Limitations of EEG:
signal not useful for pinpointing exact source of neural activity
Doesn’t allow researchers to distinguish between activity originating in different but adjacent locations
Event-Related Potentials (ERPs) measure the brain's response to specific sensory, cognitive or motor stimuli. These measure brain waves triggered by specific events
Strengths of ERPs:
high temporal resolution
Bring more specificity to measurement of neural processes
Led to widespread use of ERPs in the measurement of cognitive functions and deficits
Limitations of ERPs:
lack of standardisation in ERP methodology between different research studies makes it difficult to confirm findings
all background noise and extraneous material needs to be eliminated
Post-Mortem examination is analysis of the brain after death
post-mortems are usually carried out on individuals who have a rare disorder or have experienced unusualdeficits in mental processing or behaviours during their lifetime
Strengths of post-mortems:
Broca and Wernicke’s research relied on post mortems
Vital to foundation research
Improve medical knowledge and generate hypotheses
Limitations of post-mortems:
issues with causation. Observed damage may not be linked to deficits but other unrelated damage
Raises ethical issues - informed consent e.g HM case (lost his ability to form memories so was not able to give consent yet a post mortem happened anyway)