ways of studying the brain BP Flashcards
Functional magnetic resonance imaging (fMRI)
method used to measure brain activity while a person is performing a task. fMRi detects radio waves from changing magnetic fields which enables researchers to detect which regions of the brain are rich in oxygen and thus active.
Electroencephalogram (EEG)
a record of the tiny electrical impulses produced by the brain’s activity. By measuring characteristic wave patterns, the EEG can help diagnose certain conditions of the brain.
Event-related potentials (ERPs)-
the electrophysical response of the brain to a specific sensory, cognitive or motor event can be isolated through statistical analysis of EEG data
Post-mortem examinations
the brain is analysed after death to determine whether certain observed behaviours during the person’s lifetime can be linked to structural abnormalities in the brain.
Scanning
Scanning’s purpose in psychological research is to investigate localisation → which parts of the brain have what functions
fMRI works by
- Detects changes in blood oxygenation and flow in specific areas of the brain
- A more active brain area consumes more oxygen
- Blood flow is directed to the active area to meet the increased demand in a process called the haemodynamic response
- fMRIs produce 3D images locating which parts of the brain are involved with particular mental processes
EEG
- Measures electrical activity within the brain using electrodes that are fixed onto someone’s scalp with a skull cap
- Recording represents brainwave patterns generated by neurons and thus provides an overall account of brain activity
- Often used as a diagnostic tool as unusual activity patterns may be a sign of neurological abnormalities like epilepsy
ERPs work by
- EEG data contains all the neural responses associated with specific sensory, cognitive and motor events
- Researchers isolate these responses using a statistical averaging technique
- After filtering out all the relative responses, what remains are event-related potentials
post-mortems work by
- Patients of these examinations are likely to have had a rare disorder ot unusual deficits in cognitive processes/behaviour
- The brain is examined after death to determine the likely cause
- This may involve comparison with a neurotypical brain
fMRI strengths
- Does not rely on use of radiation
- Virtually risk-free
- Non-invasive
- Straightforward to use
- Images produced have high spatial resolution meaning that fMRI can safely provide a clear picture of brain activity
fMRI limitations
- Expensive compared to other neuroimaging techniques
- Poor temporal resolution as there is a 5 second time lag
- May not truly represent moment-to-moment brain activity
EEG strengths
- Useful for studying sleep stages and diagnosis of conditions such as epilepsy
- Extremely high temporal resolution at a single millisecond
- RWA
EEG limitations
- Generalised nature of the information received
- Signal is not useful for pinpointing exact source of neural activity
- Does not allow researchers to distinguish between activities originating in different locations f they are next to each other
ERPs strengths
- Bring specificity to to the measurement of neural processes
- Excellent temporal resolution as derived from EEGs
- Used to measure cognitive functions and deficits such as the allocation of attentional resources and the maintenance of working
ERPs limitations
- Lack of standardisation
- In order to get ‘pure’ data background ‘noise’ and extraneous material must be completely eliminated
