Ways of studying the brain Flashcards
what are the 3 scanning technique’s used when studying the brain ?
-fMRI
- EEG
- ERP
what is another technique used when studying the brain that does not involve scanning ?
- post-mortem examinations
( autopsy)
what does fMRI stand for ?
- functional magnetic resonance imaging
how does the fMRI work ?
- uses a magnetic field + radio signals to monitor the blood flow in the brain
- can be used to show activity as it occurs
why is the fMRI described to have a low temporal resolution ?
- because it shows activity about 1 second after it occurs
why is the fMRI described to have a high spatial resolution ?
- because it is accurate within 1-2mm in the brain
what is a strength of the fMRI ?
- it provides a moving picture of brain activity
- so you can see brain interactions + localisations in response to specific stimuli
what are the 3 limitations of the fMRI ?
- brain activity is complex
- machines are expensive + require trained operators
- sample sizes of studies can be small
brain activity is complex
what is the issue ?
- it makes it difficult o research and understand all of the brain processes as a whole
- we do not see the individual neuron levels just the levels of haemoglobin within the blood that passes into the brain
machines are expensive + require trained operators
what is the issue ?
- you have to rely on a trained professional to interpret the data as a researcher
- fewer scans occur due to how expensive it is so results are less likely to be replicated and so results are less reliable
sample sizes can be small
what is the issue with this ?
- results may be due to individual differences so you are unable to generalise findings to whole populations
describe what is meant by an EEG ?
- a method of measuring brain activity using electrodes attached to the scalp
what does the
EEG record ?
- it records the neuronal activity of the brain immediately under the scalp
when is an EEG used ?
- often used to aid the diagnosis / treatment of epilepsy and sleep disorders
what does an EEG produce ?
- an EEG produces a recording of alpha, beta, delta and theta waves
in what way is an ERP and an EEG similar ?
- an ERP uses an EEG machine
describe what occurs during an ERP ?
- electrodes are put on the scalp
what does an ERP detect ?
- it detects neural activity in response to a stimulus
what does an ERP measure ?
- measures brain activity in response to a stimulus / particular event
AO3 EEG
why can the finer details be missed ?
why can this be an issue ?
- the EEG signal is not useful for pinpointing the exact source of the neural activity
- and does not allow researchers to distinguish between activities originating in different but adjacent locations
- this may be an issue because this reduces the spatial resolution of the EEG
is the EEG more expensive than other scanning methods ?
- no
the EEG is less expensive than other scanning technique’s
why is the fact that the EEG is less expensive than other scanning methods ?
- this is a strength because it is more widely available so more ps can be used which reduces the possibility pf individual differences
- so greater generalisability to the population
- also more scans can occur which makes the data and findings replicable and so more valid
is the fact that an expert is required to interpret the output of the EEG and ERP a limitation or a strength ?
- limitation
- because you rely on another person to tell you the results and there is a possibility that they can miss key info that they believe is unnecessary
- adds a layer of subjectivity
- demand characteristics play a role as the interpreter knows what you are tying to study
describe what is a post-mortem ?
- examinations of the brain after death
why is a post-mortem used ?
- it is used to see where the damage has occurred
- used to correlate area of damage / abnormalities + behaviour prior to death
By what psychologist was a post-mortem used ?
- Broca used this with his patient Tan
- he correlated his speech and language problems prior to death + the area of damage (known as the Broca’s area )
AO3 for post-mortem examinations (2)
- brain is dead so cannot be used to measure brain activity
- there are issues with comparison of functioning prior to death as you may not have info about the person before death
