Techniques Used to Study The Brain Flashcards
What are the four techniques to study the brain?
- Post mortem examinations
- Functional magnetic resonance imaging (fMRIs)
- Electroencephalograms (EEGs)
- Event - related potentials (ERPs)
What is a post mortem examination?
An analysis of the brain after the person has died
When are post mortem examinations mainly used?
Post mortem examinations are mainly used to study people who display a rare disorder and have experienced unusual deficits in mental processes or behaviour during their lifetime
In post mortem examinations, areas of the damaged brain are examined. Why does this happen?
Areas of damage in the brain are examined as a means of establishing the likely cause of death
What can post mortem examination potentially involve?
Post mortem examinations may involve comparison with neurotypical brains to ascertain the extent of difference
What is an example of post mortem examinations?
An example of this work was Broca and his patient Tan, which lead to the discovery that the Broca’s area was responsible for speech
What is the full story of Tan?
This patient suffered brain damage that resulted in him only saying the word “tan”. He understood speech clearly and followed instructions. Broca performed an autopsy on Tan’s brain and found substantial damage to an area towards the base of the frontal lobe in the left hemisphere.
What were Broca’s conclusions from assessing Tan’s brain?
Broca concluded that this area of the left hemisphere, now known as Broca’s area was responsible for speech production.
What is a strength of post mortem examinations? (foundation of learning brain processes)
Post - mortem evidence was vital for providing a foundation for early understanding of key processes in the brain. Broca and Wernicke both relied on post mortem studies in establishing links between language, brain and behaviour decades before neuroimaging became a possibility. Post - mortem studies improve medical knowledge and help generate hypotheses for further study
What is functional magnetic resonance imaging (fMRIs)?
This technique measures blood flow through the concentration of oxygen in the bloodstream
What is a limitation of post mortem examinations? (cause and effect)
In post mortem examinations, establishing cause and effect is a problem. The observed differences can be unrelated to the behaviour. Another problem is that post mortem studies raise ethical issues of consent from individuals before death. Such individuals may not be able to give informed consent
Why do fMRIs use the concentration of oxygen in the bloodstream to measure blood flow?
Blood flow to active areas of the brain should be high because there is an increased demand for oxygen in the area. As a result the brain responds to this demand by increasing blood flow, delivering oxygen in the red blood cells
How is blood flow measured by fMRIs?
Blood flow is measured by radio waves and magnetic fields
How do researchers show the mental activity in the brain?
Researchers are able to produce maps showing which areas of the brain are involved in a particular mental activity
What is a strength of functional magnetic resonance imaging (fMRIs)? (less risk and harm)
Unlike other scans (such as PET scans) fMRIs do not rely on the use of a radioactive tracer. Additionally, administered correctly, fMRIs are virtually risk free, non invasive and straightforward to use. Minimising risk and harm to patients.
