ways ways of studying the brain Flashcards
what is an fMRI
Measures blood flow using magnets. More activity in a brain area will lead to reduction in oxygen, so more oxygen will be transported to that area. Can ask person to do certain tasks whilst being monitored, and oxygenated blood flow is tracked.
strengths of fMRIs
High spatial resolution – is able to establish localisation of function in a living person
limitations of fMRIs
Not a direct measure so lacks temporal resolution – there will be a delay between the brain activity and the rush of oxygenated blood response
what is an EEG
Measures electrical activity using electrodes on the scalp. Can tell a lot from the frequency (speed) and amplitude (size) of the waves produced (alpha, beta, theta, delta). Often used for sleep research
strengths of EEGs
Can test in real time (high temporal resolution), as it is a direct measure of neural activity
limitations of fMRIs
Poor spatial resolution – the scalp is a good conductor, so it is not clear exactly where the brain activity is happening
what is an ERPs
Similar to EEG, but focuses on one small electrical change in the brain. Person is asked to complete the same task over and over again, and researchers identify the recurring brain activity – this helps to reduce the ‘noise’ of other activity.
strengths of ERPs
Very specific measure and is direct – has excellent temporal resolution and can establish stimulus-response
limi of ERPs
Needs lots of trials, which limits the type of task being asked – for example, would be difficult to present ‘funny’ or ‘scary’ stimulus dozens of times with the same effect
what is a post mortem
Thorough examination of the brain after death. Can then correspond the features of the brain with different traits of the person during their lifetime.
strengths of post mortems
Detailed analysis, can be more thorough, e.g. weighing areas
limitations of post mortems
Retrospective. Can’t see cause and effect – for example, the cause of death could affect the brain
