Ways of studying the brain Flashcards
What is functional magnetic resonance imaging (FMRI) ?
Works by detecting the changes in both blood oxygenation and flow that occur as a result of neural activity in specific parts of the brain.
When a brain is more active, it consumer more oxygen and blood flow is directed to different places.
It allows scientists to see what parts of the brain are involved in particular mental processes.
Strengths of functional magnetic resonance imaging (FMRIs)
It does not rely on the use of radiation.
It is risk free, non-invasive and straightforward to use.
It produces images that have very high spatial resolution, and provides a very detailed picture of how brain activity is located.
Limitations of functional magnetic resonance imaging (FMRIs)
They are expensive compared to other techniques.
Poor temporal resolution because there is around a 5-second time lag behind the image of the screen and the initial firing of the neuronal activity.
Does not truly represent moment-to-moment brain activity.
What is an Electroencephalogram (EEG)?
It measures electrical activity within the brain via electrodes that are fixed to an individuals scalp using a skull cap.
The scan recording represents the brainwave patterns that are generated from the action of thousands of neurones, providing an overall account of brain activity.
Strengths of an EEG
It has been useful in studying the stages of sleep and the diagnosis of conditions such as epilepsy.
It has high temporal resolution and can detect brain activity at a resolution of a single millisecond.
limitations of EEGs.
Can’t pinpoint the exact source of neural activity.
Researchers can’t distinguish between activities orientating in different but adjacent conditions.
What are event-related potentials?
The electrophysiological response of the brain to a specific sensory, cognitive or motor event can be isolated through statistical analysis of EEG data.
Strength of ERPs
They bring much more specificity to the measurement of neural processes than could ever be achieved using raw EEG data.
They have high temporal resolutions.
Limitations of ERPs.
Lack of standardisation in ERP methodology between the different research studies, which makes it difficult to confirm findings.
Background noise and extraneous material must be completely eliminated.
What is a post-mortem examination?
Where the brain is analysed after death to determine wether certain observed behaviours during the persons lifetime can be linked to structural abnormalities in the brain.
Strengths of a post mortem examination.
Vital for early research into the brain. Broca and Wernick both relied on post-mortem studies.
Limitations of a post mortem examination.
Ethical issues of consent from the individual before death.
Observed damage to the brain may not be linked to the deficits under review but to some unrelated trauma or decay.
