Ways of studying the brain

What is a fMRI

Measures change in blood flow and oxygen levels. When an area of the brain becomes more active it requires more oxygenated blood, this shows up as bold.

AO3 - fMRI high spatial resolution

fMRI can produce very detailed images of the brain, allowing researchers to identify where activity is occurring.

AO3 - fMRI investigate the active brain

Participants can perform tasks while being scanned, allowing researchers to investigate which brain areas become active

AO3 - fMRI poor temporal resolution

There is a delay of several seconds between neural activity occurring and the bold response being detected. Meaning fMRI is less effective at showing exactly when neural activity occurs

AO3 - fMRI expensive and restrictive

fMRI are expensive meaning participants have to remain very still inside the scanner. This makes it difficult to investigate some behaviours in realistic situations

What is an EEG?

An EEG measures the brain's electrical activity using electrodes placed on the scalp. The electrodes detect the combined electrical activity produced by large groups of neurons.

AO3 - EEG very high temporal resolution

EEG can detect changes in brain activity within milliseconds, making it useful for measuring exactly when neural activity occurs

AO3 - EEG are cheap

Cheap, portable, non invasive compared with other methods

AO3 - EEG poor spatial resolution

As electrodes measure activity across large areas of the brain, it can be difficult to determine exactly where activity is occuringoccurring

AO3 - EEG affected by background noise

Electrical signals can be affected by background noises which can make the data more difficult to interpret

What is ERPs?

Electrodes fixed to a participants scalp to detect neuronal activity to investigate activity in response to a stimulus

AO3 - ERP high temporal resolution

Can measure the timings of brain responses to a stimulus with very high precision

AO3 - ERP real life application

Used to investigate specific cognitive deficits and disorders, helping researchers understand differences in brain processing

AO3 - ERP low spatial resolution

Only measure superficial regions of the brain. Cannot discriminate between different regions with accuracy

AO3 -ERPs affected by background electrical activity

Can be affected by background electrical activity and extraneous material, meaning statistical averaging is needed to isolate the response to the specific event

What is post-mortem?

Examination of the brain after death. Researchers may compare the brain with a healthy brain to identify abnormalties

AO3 - post-mortem advance our understanding of localisation

Broca's examination of the brain of patient Tan provided evidence for the role of Broca's area in speech production

AO3 - Post-mortem examine brain in great detail

Examine the brain in great detail, including areas of damage that are not easily investigated in other methods

AO3 - post-mortem individual cases

Often based on individual cases, meaning findings may have limited generalisability to the wider populahan

AO3 - post-morton ethical issues

Individuals cannot give consent for examination after death. So researchers rely on consent from relatives or prior to death