Ways Of Studying The Brain Flashcards
What is the purpose of scanning in psychological research?
To investigate localisation
How does FMRI work?
By detecting the changes in blood oxygenation and blood flow that occur as a result of neural activity in specific parts of the brain
When a brain is more active what does it consume more of
Oxygen
To meet the increased demand of oxygen when the brain is more active what happens to blood flow?
Blood flow is directed to the active era (haemodynamic response)
What type of image does FMRI produce and what does this show? Why is this important?
Three-dimensional images which show which parts of the brain are involved in a particular mental process.
This has important implications for our understanding of localisation of function
What does an EEG measure?
Electrical activity within the brain via electrodes that are fixed to an individuals scalp using a skull cap
What does the scan recording of an EEG represent?
The brainwave patterns that are generated from the action of thousands of neurones providing an overall account of brain activity
Who often uses EEGs and why?
Often used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity may indicate neurological abnormalities e.g. epilepsy or tumours
What is contained within EEG data?
All the neural responses associated with specific sensory, cognitive and motor events that may be of interest to cognitive neuroscientists
What remains after researchers filter out all the extraneous brain activity from the original EEG recording?
Event-related potentials
What are ERPs?
A type of brain wave that’s triggered by particular events
What has research revealed about ERPs?
Many different forms and how these are linked to cognitive processes e.g. attention and perception
What are post-mortem examinations?
A technique involving analysis of a person’s brain following their death
What is examined after death in a post-mortem for psychology?
Areas of damage within the brain as a means of establishing the likely cause of the affliction the person experienced
What might a post-mortem involve?
Comparison to a neurotypical brain to ascertain the extent of the difference
Evaluation FMRI: doesn’t rely on radiation
- unlike PET scans
- if administered collects virtually risk-free, non-invasive and straightforward to use
- produces images with high spatial resolution which depicts detail by the millimetre and provides a clear picture of how brain activity is localised
- therefore FMRI can safely provide a clear picture of brain activity
Evaluation FMRI: expensive
- expensive compared to other neuroimaging techniques
- poor temporal resolution because there is around a 5 second time lag behind the image on screen and the initial firing of neuronal activity
- FMRI may not truly represent moment-to-moment brain activity
Evaluation EEG: useful in studying the stages of sleep and in diagnosis
- EEG has high temporal resolution
- todays EEG technology can accurately detect brain activity at a resolution of a single millisecond
- EEG has some real world usefulness
Evaluation EEG: generalised information
- EEG signal is not useful for pinpointing the exact source of neuronal activity
- doesn’t allow researchers to distinguish between activities organising in different but adjacent locations
Evaluation ERPs: bring more specificity
- bring more specifics to the measurement of neural processes than could be achieved with a raw EEG
- excellent temporal resolution
- ERPs are frequently used to measure cognitive functions and deficits such as the allocation of attentional resources and maintenance of working memory
Evaluation ERPs: limitations
- lack of standardisation in ERP methodology between different research studies which makes it difficult to confirm findings
- in order to establish pure data in ERP studies background ‘noise’ and extraneous material must be completely eliminate - not always easy to achieve
Evaluation Post mortem: strengths
- vital in providing a foundation for early understanding of key processes in the brain
- Brocka and Wernicke both relied on post-mortem studies in establishing links between language, brain and behaviour decades before neuroimaging ever became a possibility
- Post-mortem studies were also used to study HM’s brain to identify the areas of damage which could be associated with his memory deficits
- post-mortems provide useful information
Evaluation ERPs: limitations
- causation is a issue however observed damage to the brain may not be linked to deficits under review but to unrelated trauma or decay
- raise ethical issues of consent from the individual before death - participants may not be able to provide informed consent e.g. HM who lost his ability to form memories and wasn’t able to provide such consent
- challenges post-mortems usefulness in psychological research
