Methods of Studying the Brain Flashcards
how does fMRI work?
detects the changes in blood oxygenation and flow that occur as a result of activity in specific parts of the brain
what does fMRI stand for?
functional magnetic resonance imaging
what is the haemodynamic response? (fMRI)
when a brain area is more active, it consumes more oxygen, and to meet this demand, blood flow is directed to the active area
what does an fMRI do?
produces 3D images (activation maps) showing which parts of the brain are involved in a particular mental process
this has important implications for our understanding of localisation of function
what are the strengths of fMRI?
does not rely on the use of radiation. if administered correctly, it is virtually risk-free, non-invasive and straightforward to use
high spatial resolution
what are the weaknesses of fMRI?
expensive
can only capture a clear image if someone is perfectly still
poor temporal resolution (5-second time lag)
can only measure blood flow, can’t home in on specific neurons, so it is difficult to tell exactly what kind of brain activity is represented on screen
what does EEG stand for?
electroencephalogram
what does an EEG do?
measures electrical activity within the brain via electrodes fixed to the scalp using a skull cap
what do EEGs show?
shows the brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity
can EEGs detect epilepsy?
yes
what are the strengths of EEGs?
valuable diagnosing conditions such as epilepsy, which is characterised by random bursts of activity in the brain that can be easily detected on screen
contributed to understanding in stages of sleep
high temporal resolution
what are the weaknesses of EEGs?
generalised nature of information received
poor spatial resolution
what does ERPs stand for?
event-related potentials
what do EEG data contain that may be of interest to cognitive neuroscientists?
neural responses associated with specific sensory, cognitive and motor events
how are ERPs obtained?
a statistical averaging technique is used to remove all extraneous brain activity from the original EEG recording, leaving only the responses relating to the presence of a specific stimulus or performance of a specific task
what are the strengths of ERPs?
excellent temporal resolution
much more specific than raw EEG data
what are the limitations of ERPs?
lack of standardisation makes it difficult to confirm findings
in order to establish pure data, all extraneous material such as background noise must be completely eliminated, which is not always easy to achieve
what is a post-mortem examination?
a technique involving the analysis of a persons brain after death
what are post-mortem brains compared to?
neuro-typical brains so as to ascertain the extent of the difference
what are the strengths of post-mortem examinations?
vital in providing a foundation for early understanding of key processes in the brain
improves medical knowledge and helps generalise hypotheses for further study
what are the weaknesses of post-mortem examinations?
damage can be caused during the post-mortem process
ethical issues as the patients may not have given their consent before death
can’t be sure damage is linked to issues under review, cold version due to some unrelated trauma
