Ways of studying the brain Flashcards
How does FMRI work?
It detects the abnormalities in the brain by checking which mental process is controlled by which part
What does it detect?
Changes in the blood flow and oxygenation that happens because of a certain brain activity
What does a brain require when it is active?
When there is a certain part of a brain that is active it will require more blood and oxygen.
How does FMRI show this?
This will be shown through its 3 dimensional image.
Strengths of FMRI
Has high spatial resolution, meaning it allows us to see images in great detail
Why is having high spatial resolution a strength?
It ensures that when the doctors are making their observation on the brain it is accurate, and allows them to detect exactly where the issue is located so that it can be treated quicker.
What is a limitation?
It is too expensive, not all patients will be able to afford this and therefore would have to use other scanning techniques. Thus is a limitation because it will be used by less members of the society.
Who is it less effective on?
On those who struggle to stay still, for instance, if they suffer from things like tics. Cannot be used for wide range of participants and therefore it reduces the practical value.
Strength of FMRI
It is much more convenient to use as this does not involve cutting up and seeing the brain, thus is non-invasive, risk-free and therefore more patients will use it.
Why does that have practical value?
It allows medical professionals to use this technique to clearly identify parts of the brain and what can happen in certain regions that are damaged. This then can help in developing therapies and explanations for certain disorders.
What is EEG scanning?
This looks at the electrical activity within the brain by attaching a skull cap in the patients head.
What will the scan show?
The scan will show the brain wave pattern that has been happening within the patient’s mind due to the activity of thousands of neurons
What else does this help in showing?
If a person has any brain disorders like epilepsy
Strengths of using EEG
It has real-world application, this is because it allows us to detect even the smallest movements in the brain so it helps in identifying if the patient will suffer from any brain disorders.
Why is that a strength?
Because it will have practical value, for instance, it will help them find treatments quicker and therefore will increase the chances of them curing the disorder, or they could find ways to deal with the symptoms that they are likely to experience. This, therefore, makes their lives more convenient.
What else has EEG contributed to?
The development of the different sleep stages, and in helping us understand that the sleep cycle lasts for around 90 minutes and is rhythmic.
Limitations of EEG
It has a poor spatial resolution, meaning the pictures are not clear so doctors cannot be accurate in their judgments. The scan does not even allow us to see what part of the brain is what. It also cannot detect the deepest and most important part of the brain: the hypothalamus.
Whys that a limitation?
Because it makes it difficult to draw out conclusions, the diagnosis and observation made by the doctors therefore may not always be correct and it could instead hinder the patients lives.
What else does it fail to do?
Cannot tell us where exactly the issue is located in because the electrical activity is all over the brain.
Strength of EEG:
It has a good temporal resolution, 1-10 milliseconds, meaning that when it is recording the brain, it does it in real-time so we see the most recent activities. So it increases the credibility as it will be high in internal validity.
But what reduces the reliability of the reading?
The fact that it is really uncomfortable to wear so the reading on the scan could have changed because of the patients discomfort rather than an actual brain activity.
What is ERP
They also look at the electrical activity by attaching a scalp cap in the patients head
What makes ERP different from EEG?
EEG is recording the general brain activity of the brain which is linked to states like sleep whereas ERP is trying to isolate a single response that occurs due to a stimulus presented to the participant.
Strength of ERP
It also has high temporal resolution, so the same evaluation can be applied here from the EEG.
Limitations of ERP
Also has low spatial resolution, same evaluation as EEP
What does post mortem examinations mean?
This is when the brain of a dead person is studied, but that brain will usually have rare characteristics. They can also be compared to normal brain to see the differences.
Example of post mortem:
The case study of Tan done by Broca
Strength of post mortem:
They have clear real-world value. For instance, knowing about the difficulties that Tan suffered through it allowed us to understand that there is a part of the mind that controls speech production and damage of it can lead to expressive aphasia.
Why is that a strength?
It allowed us to find treatments and therefore has positive economic benefits as functioning members can return back to society.
Limitations of post mortem:
The patients may not be able to give proper consent as they have brain disorders and therefore it should be given to their guardian who is able to think with a clear mind and understand the consequence on the patient if they agree to do this.
Limitations of post mortem:
There is an issue of causation. Everyone lives their lives differently, and there will be many extraneous variables like age, gender, the age of brain damage etc. that will be important when looking at post mortems.
