Ways of studying the brain Flashcards
What is the purpose of scanning in psychological research
To investigate localisation- which parts of the brain do what
How do FMRIs work
Detects changes in blood oxygenation and flow
-More active areas need more oxygen so more blood flows there (haemodynamic response)
-Makes activation map to show which brain areas involved in particular mental process
How do EEGs work
Skull cap with electrodes measures electrical activity
-Scan shows brainwave patterns caused by neurons. shows overall brain activity
How are EEGs used
As diagnostic tool
-Unusual patterns of activity may indicate neurological abnormalities
How is EEG info filtered
Using statistical average techniques
-Extraneous brain activity filtered out- only relevant responses left (ERPs)
What are ERPs
Event related potentials:
-Types of brainwave that are triggered by particular events
What are post-mortem examinations
Analyse brain after death to find cause of affliction
-Sometimes compared to neurotypical brain
Strength of FMRI
No radiation (unlike PET) so mostly risk-free, non-invasive and straightforward to use
Weakness of FMRI
-Low temporal resolution (5s lag)
-Also expensive
=May not truly represent moment-to-moment brain activity
Strength of EEG
-Useful studying stages of sleep/diagnosis (e.g epilepsy)
-High temporal resolution
=Shows real-world usefulness
Weakness of EEG
Generalised nature of info received
-Signal not useful for pinpointing exact source of neural activity
=Can’t distinguish activities happening in different but adjacent locations
Strength of ERP
More specific measurements than EEG
High temporal resolution
=Often used to measure cognitive functions/deficits (maintenance of working memory)
Weakness of ERP
Lack of standardisation in ERP methodology between different research studies
=Difficult to confirm findings
Strength of post-mortem
Vital in early understanding of brain (e.g HM/Broca and Wernicke)
Continues to provide useful information
Weakness of post-mortem
Causation is issue as observed damages may be caused by other thing and not linked to deficits under review
Ethical issue of informed consent (e.g HM)
=challenges usefulness
