Discuss two of the following methods that have been used to investigate areas of cortical specialisation in the brain: post-mortem examinations, EEG and scanning techniques (10 marks) A method of investigation of cortical specialisation simply addresses the technique/s in which the brain of a person has been examined, in order to give the investigator a more detailed understanding of the different parts of the brain. Over the last few decades, technology has vastly improved, and thus improved the biological psychologist’s ability to study the brain. Methods in which this is done can be either invasive or non-invasive, and all have their benefits and disadvantages. The two that I shall discuss are post-mortem examinations, and scanning techniques.
Post mortem studies are research methods conducted with the main focus being the neurobiology in the brain, and the brain having belonged to a person with certain illnesses, of which have been studied whilst the subject was alive. Such diseases can include Alzheimer’s, or other afflictions such as inabilities to speak or even paralysis. All these are investigated during the post mortem, as with all other experiments, the examinations must be repeated to ascertain a valid analysis. Post mortem studies are older than any scanning techniques, and though primitive, had been used to study the relation between the brain and corresponding behaviours.
Post mortem aids in finding out missed diagnoses and help in preventing repetition of these medical errors in future cases. Thus it helps in improving the quality of medical care for other similar patients. Mortality statistics can be created, and prevents death certificates, in the absence of post mortem findings, yielding inaccurate data. As a result of two separate post mortems, Paul Broca and Karl Wernicke discovered their own respective areas- Broca’s area and Wernicke’s area. Broca used many subjects, and learnt that his area was linked to speech production, and consequently aphasia. He discovered in one of his patient’s (a man nicknamed ‘Tan’, as it was the only word he could produce) brain that there was an injury or lesion brought about by syphilis, causing ‘Tan’’s aphasia. Wernicke similarly used post mortems, but concentrated on patients with little rather than no language production. Both studies have given more understanding as to how more thorough and detailed examination of the brain, especially on how the left hemisphere is responsible for language and speech.
As to be expected, there are numerous ethical points about this invasive method of cortical examination, and one of the main ways that have enabled post mortem examinations to be more widely accepted is the regulations set forth by the Human Tissue Act of 2004. Post mortems in the name of research (rather than necessity deemed by the Coroner) can only occur with the permission of the deceased and additional relatives. All removal, storage and use of organs must be fully authorised and appropriate. They must be carried out in authorised places, and post mortems done for research must be allowed by the Research Ethics Authority. All this ensures that post mortems are conducted in a way that avoids criticism and scandal, and gives more credibility and integrity to the research.