ways of measuring the brain

fMRI

detects changes in blood oxygenation and blood flow occurring as a result of neural activities in the brain, when a brain area is more active more oxygen is consumed so blood flow redirected to that area - haemodynamic response

strengths of fMRI

does not rely on use of radiation, non-invasive, risk free, easy to use, images have high spatial resolution - safely provides clear picture of brain activity

limitations of fMRI

expensive, poor temporal resolution - 5 second time lag between image on screen and initial firing of neuron, does not truly represent moment-to-moment brain activity

EEG (electroencephalogram)

measures electrical activity in the brain via electrodes stuck to scalp, scan recording represents brainwave patterns generated from action of thousands of neurons providing overall account of brain activity

strengths of EEG

useful as diagnostic tool for arrhythmic patterns of brain activity, can indicate neurological abnormalities such as tumours epilepsy or sleep disorders, high temporal resolution - can detect brain activity at resolution of single millisecond

limitations of EEG

info received is too generalised (from lots of neurons) so signal not useful for pinpointing exact source of neural activity, does not allow researchers to distinguish between activities originating in different but adjacent locations

ERP (event related potential)

statistical averaging technique used so all extraneous brain activity from original EEG recording are filtered out to leave only responses related to specific stimulus, ERPs are the brainwaves triggered by particular events

strengths of ERP

addresses limitations of EEGs - bring more specificity to measurement of neural processes, very good temporal resolution, used to measure cognitive functions and deficits such as allocation of attentional resources and the maintenance of working memory

limitations of ERPs

lack of standardisation of ERP methodology between different research studies, not always easy to remove background brain activity, some processes cannot be studied because cannot be presented large number of times with same response

post-mortem examination

analysis of person’s brain following death, areas of damage within brain compared to neurotypical brain to ascertain the extent of difference

strengths of post-mortem examination

vital in providing foundation for early understanding of key processes in brain

limitations of post-mortem examination

correlation does not equal to causation - may be some unrelated trauma and decay, ethical issues regarding consent of individual before death