To what extent can neurophysiology studies of brain-damaged individuals inform our understanding of the organization of mental processes in the brain? BY near To what extent can neurophysiology studies of brain-damaged individuals inform our understanding of the organization of mental processes in the brain? People have been fascinated with the brain, the key to making us all unique Individuals, for many years. Despite this interest, neurophysiology is a fairly recent development, and it can be simply defined as a ;relationship between brain actively/structure and unction’ (Martin, Carlson & Buskins, 2010).
The aim of this particular branch in psychology is to gain understanding of the brain and how it functions by Investigating people who are brain damaged by a variety of causes (Lurid, 1973). We learn more about the organization of mental processes by looking at what cognitive problems occur when the brain Is Injured In specific parts. From this, we can assume that the specific part is in some way involved in that process (Rose & Johnson, 1996). This is known as functional localization. According to the model of functional localization, It should be easy to predict the outcome of damage to a specific area in the brain.
However. There have been several cases which do not fit with this Idea (neurophysiology, n. D). One of the first and most well-known accidental cases which caused brain-damage, was seen In 1848, when Phonies Gage, a rail-worker In the us had an accident where an iron rod, more than an inch in diameter, smashed into his head through his left cheek and came out of his forehead (Harrow, 1848 as cited by Rose Johnson, 1996). Despite the rod destroying several areas of his brain, Phonies only showed a resonantly change, which was quite remarkable considering the extent of his injuries (as cited by Rose , 1996).
The lack of problems with his mental processes do not fit with the Idea of functional localization. If it did then the model predicts that the damage done to the frontal lobes, should have affected Cages sensory, motor and major cognitive functions, such as language and memory (Hill, 2009)_ This case study suggests that the functional localization theory Is perhaps an over-simplified version of how the brain actually works. Experiments like Phonies Sage’s, causes less ethical issues than other ethos, as researchers are Investigating damage which NAS occurred ;naturally;.
There are however, Issues with this method as well. One problem is that there Is a lack of precision in that the amount of damage has not been controlled and therefore It Is difficult to measure (Hill, 2009). Another Issue Is that It Is hard to make comparisons with what Gage was like before the accident and after, as this intimation is provided solely on retrospective accounts trot trends and family (Hill, 2009). This makes the Information less objective. It is possible that the personality hanged in Gage may not have been caused by the physical damage but may have him less sociable (Macmillan, 2008).
Despite these methodological issues, Sage’s case study did provide some further understanding. It was the first study of its kind to show real proof that injury to parts of the frontal lobes caused personality changes, and rather recently, after further analysis of Sage’s skull, it has been discovered that the frontal cortex is responsible for this change (Coastland, 2010). As a result of this new development, this could have led to the development of frontal lobotomies-a form of surgery which teaches the frontal lobes from the other parts of the brain (Careered, 2008). T also helped develop the understanding of brain surgeons, who were quite fearful at the time, of causing the death of patients whilst operating on the brain and removing tumors. This study showed that in the brain, some areas could be removed without leading to the serious consequences assumed before (Careered, 2008). Studies such as Ferrier (1876) found similar results in monkeys after ablations of the frontal cortex Joseph, 2000). These were also found in a study of monkeys and cogs conducted over a three decade period by Bianca (1922).
He found that while frontal ablations to one side of the brain did not have much effect, when done on both sides of the brain whilst it did not affect motor and sensory functions, it did cause a personality change (Groomer et al. , 1999). However, these results were found in animals and as some researchers have found differences between brain structures in human individuals (Amounts et al. 1999 as cited by Martin et al. , 2010), it can be logically deduced that there will be much more difference between a monkeys and a human brain. Another example of brain-damage was the case of HEM.
He suffered from severe epilepsy for many years before being operated on by DRP Seville in the sass’s. Seville removed the parts of the brain he thought were causing the fits, the temporal lobe, and despite his epilepsy getting slightly better, the consequence was much bigger (Careered & Flanagan, 2008). Although his personality stayed the same, HEM was unable to remember some memories up to ten years before undergoing surgery. This is known as interrogated amnesia and is caused by damage to the hippopotamus. As well as this, he could not form any new Eng term memories; this is called retrograde amnesia (Careered & Flanagan, 2008).
While Ham’s procedural memory- his memory for skills, was intact and allowed him to form new memories for habits and skills, however his episodic memory, which held his memory for events that occurred in his life was severely impaired. This supports research that suggests there are different types of long-term memory (Careered & Flanagan, 2008). However, this does fit in with the functional localization theory. If the hippopotamus was where memory is based in the brain, then we would assume hat damage to this area would prevent all new memories from being formed, not just long term but short term memories as well.
As this is not the case, it is clear that memory is not stored in a specialized area within the brain, but is situated across several different areas (Hill, 2009). Although, the extent of damage is a bit more controlled than in accidental cases, some researchers have argued that Just because the removal of or damage too certain area appears to cause a deficiency in a specific function, it does not necessarily mean that that is what is responsible for the unction. It could be that the injury may have disrupted neighboring areas in the is also the issue of individual differences.
Studies, such as Amounts et al. (1999), have found that there is variation in the regional structure of the brain between individuals. Therefore without taking into consideration the sex, age, personality and intellect of a person, it makes it harder to generalist to other cases (Martin et al. , 2010). There is also the ethical issue that as HEM cannot remember what happens to him, he could not possibly have given his consent to take part in such experiments. Perhaps he did not fully understand what was happening to him (Careered & Flanagan, 2008).
As well as showing strong evidence that memory is not situated in one specialized area of the brain, this study also showed that whilst the hippopotamus’ involvement was essential in the formation of new memories, old memories were not stored in this area. Ham’s case has also provided neurophysiology’s with evidence regarding short-term memory. He was only able to estimate time for a maximum of seconds, which provides support for the suggestion that the duration of STEM only lasts this long (Peterson and Peterson, 1959 s cited by Careered & Flanagan, 2008).
HEM was considered to be the greatest patient of neurophysiology, spending most of his life contributing and taking part in experiments which helped develop our understanding of the brain a great deal (Byrne, n. D). Studies which confirm the findings of this include the case study of Clive Wearing (Biddable, 1990). He was a British man who had a viral infection which affected his ability to transfer short-term memories to long term, exactly like HEM. His hippopotamus and the surrounding areas were also similarly affected.
His procedural Emory continued to function but his episodic memory ceased to function as well (Careered & Flanagan, 2008). As case studies are usually hard to generalist from, similar evidence which is found in another patient lessens the chance that the conclusions drawn are only valid for that particular case. From this it can be logically assumed that there is a connection to the damaged areas of the brain and the specific function being investigated (Careered & Flanagan, 2008). In conclusion, our understanding of the brain has developed incredibly over recent decades.
This development is mainly due to case studies, like Phonies Gage and HEM which have further questioned the functional localization theory and have provided strong evidence for the fact that although the brain is made up of specialized areas that carry out different functions; these are not specified to a certain region (Hill, 2009). There is strong evidence for memory being distributed across separate sections of the brain; however to progress further, more research needs to be done into where these areas are situated, and what each area is responsible for.