Ways of Studying the Brain Flashcards
What are post mortem examinations?
when a person’s brain is examined after they have died.
They can used to see where damage has occurred and how that might explain behaviour exhibited by the person after their death
Give an example of what would be studied in a post mortem examination.
Alxheimer’s disease, damage can be seen to the area of the brain involved in memory and language so we can potentially find a way to reduce the impacts of the damage
What is used in modern post mortem examinations?
post mortem brain slicing; the brain can be sliced into thin sections and studied on a microscope to detect abnormalities
What are the advantages to post mortem examinations?
- allow detailed examinations of the anatomical aspects of the brain that is not possible with the non-invasive technique
- researchers can accurately examine deeper regions of the brain and potential links to behaviour
- Harrison (2000) suggested that structural and neurochemical abnormalities linked to schizophrenia were first identified using post mortem examine
What are the disadvantages to post mortem examinations?
- retrospective method so it may be hard to make comparisons with functioning before death
- as soon as oxygen is cut off from the brain, the shape and structure may change, so findings may lack accuracy
What is functional MRI scans (fMRI)?
uses strong magnetic and radio waves to monitor blood flow in the brain during a particular activity. It takes repeated scans (usually one a second) to create an image of the concentration of oxygen in the blood.
Areas of high activity will show correspondingly high levels of blood oxygenation and blood flow. This allows sections of the brain that are particularly active during different tasks to be identified
What are the advantages of fMRI scans?
- provides a moving picture of brain activity rather than just the blood physiology of the brain. This is highly valuable when trying to link brain activity to key behaviours
- it is non-invasive and does not expose the brain to potentially harmful radiation as can be found in other brain scanning devices, hence is an ethical method
What are the disadvantages of fMRI scans?
- The complexity brain activity meant interpreting the scan is quite complex and problematic
- it focuses only on localised activity of the brain may not identify important ways in which communication between different regions affects mental health
What are electroencephalogram (EEG) scans?
a test used to evaluate the electrical activity in the brain. Brain cells communicate with each other through electrical impulses. An EEG can be used to help detect potential problems associated with this activity.
An EEG tracks and records brain wave patterns. Small flat metal discs called electrodes are attached to the scalp with wires. The electrodes analyze the electrical impulses in the brain and send signals to a computer that records the results.
What are the advantages of EEGs and ERPs?
- non-invasive
- do not use radiation or involve inserting instruments directly into the brain and are therefore virtually risk-free.
- Furthermore, EEGs are much cheaper techniques in comparison with fMRI scanning and are therefore more readily available.
Consequently, this should allow more patients/participants to undertake EEGs, which could help psychologists to gather further data on the functioning human brain and therefore develop our understanding of different psychological phenomena, such as sleeping, and different disorders like Alzheimer’s.
What are the disadvantages of EEGs and ERPs?
- poor spatial resolution having greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy.
- EEGs only detect the activity in superficial regions of the brain. Consequently, EEGs and ERPs are unable to provide information on what is happening in the deeper regions of the brain, making this technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm.
- It could be argued that EEGs are uncomfortable for the participant, as electrodes are attached to the scalp. This could result in unrepresentative readings as the patient’s discomfort may be affecting cognitive responses to situations.
What are ERP scans?
Event-Related Potentials (ERP) use similar equipment to EEG, i.e. electrodes attached to the scalp. However, the key difference is that a stimulus is presented to a participant (for example a picture/sound) and the researcher looks for activity related to that stimulus.
