Neuro Surgery- Description
An area of the brain is deliberatly destroyed or opereated on in some way to see how behaviour is affected. The most common form of labotomy was on the frontal lobes. Given there role in high mental functioning, this caused people to become passive and unresponsive with low intelligence and lack of emotion. Today, this form of surgery is rare and only used as a last resort in severe cases of OCD.
Neuro Surgery- Strengths
- Allows for greater precision in locating damage in the brain.
-Allows us to compare behaviour before and after surgery.
-Lesions can cause brain damage or reduced functioning to other adjecent areas
-Difficult to establish cause and effect for a psychological disorder because we cant determine whether it was caused by the brain defect or whether the disorder caused the defect
-Removing part of someones brain only shows how the rest of the brain functions and not the fuction of the removed part.
-Ethical issues of irreversible damage in non-humans
-Cannot generalise findingsfrom animal research to explain human behaviour
Post-Mortem Examinations- Description
This is a method, in which the brain of a passed patient, usually with a known disorder or brain damge. It allows for identification of abnormality areas in the brain, and any damage can be related to symptoms/ behaviours shown when they were alive.
Post-Mortem Examinations- Strengths
-Allows us to neatly correlate an abnormality in the brain with a know disorder in a patient.
-The abilty to repeat a post-mortem examination in the same way to establish a more accurate correlation, make it more reliable.
Post-Mortem Examinations- Limitations
-Difficulties in locating a human brain- especially if disorder is rare.
-Ethical considerations- consent is needed from relative to conduct the examination, even if consent is given, they have the right to limit the scope of examinations by excluding certain organs.
There are a number of different types of scanning techniques which are used to measure the activity of the brain and cortical activity in particular. CAT scans show horizontal sections of the brain, and MRI scans show detailed images or a persons brain and activity. PET scans involve an invasive measure of injecting a radio active chemical such as glucose into the bloodstream of an individual. This mean we can determine which parts of the brain are active when a person is engaged in a particular task.
-MRI and CAT scans are non invasive and are therefore more ethical.
-PET scans show the chemical functioning part of the brain.
-PET scans are invasive- patients must give informed consent, meaning they must be made aware that this form of scanning involves the injection of radioactive glucose.
-Radioactive exposure in PET scans mean there is a limited amount of times a patient can undergo this proceedure, and certain people are exempt.
-As the brain is always active, we cannot say a particular part is specifically responsible for a certain task.
-Results can show different conclusions in different individuals meaning the results are not generalisable.