Posted at 11.12.2018
The brain is split into 4 lobes which can be seen by fissures in the skull. At its highest level the brain is divided into 2 halves, known as the right and remaining hemispheres, these hemispheres were created within an asymmetrical way. Which means that each part of the brain is specialized towards specific areas, the right hemisphere dominates visio-spatial duties and artificial / all natural thoughts whereas the still left hemisphere dominates words especially speech and writing as well as logical and analytical thoughts. These lobes are called; the pre-frontal cortex which mainly deals with higher order thinking, such as personality and handling primary motor and sensory data. The occipital lobe, which handles visual popularity. The parietal lobe, which handles recognising sound and linking it to ram, also it tackles a person's balance and position by using the somatosensory cortex located at the front of the parietal lobe, which is associated with the electric motor cortex which is located within the pre-frontal cortex. . Finally the temporal lobe most commonly known for understanding and producing words which is often traced into two areas, Wernicke's area, where terms is comprehended and Broca's area, where vocabulary is produced.
Language is both localised and lateralised; this is seen by using both divided brain patients and normal patients by using the Wada test. The Wada test will involve briefly paralyzing one of the hemispheres in the individuals brain; this effectively shuts down that hemispheres words and storage skills so the other hemisphere can be assessed. Using this method it has been possible to show that while most terminology skills are innately dominate in the left hemisphere there are some vocabulary skills in the right. The explanation for this can be that having two vocabulary centres within the brain may cause 'competition' within the brain which could cause problems such as stuttering. Localisation of words can be seen in Wernicke's & Broca's areas, both appear in the remaining hemisphere, in the temporal lobe, these areas show how localisation works. Wernicke's area handles language comprehension while Broca's area handles the production of language. Localisation is apparent in brain destruction patients. Those with damage to Wernicke's area are unable to comprehend dialect but can still fluently speak, although because of their lack of comprehension this brings about fluent aphasia. While destruction across Broca's area contributes to the individual being unable to communicate but completely in a position to understand known as non-fluent aphasia.
Furthermore emotion is another major signal of lateralisation within the mind similar to how language is lateralised, however unlike language the right hemisphere appears to be dominate when it comes to emotion. This was shown in Gainotti (1972) with brain damaged patients. Gainotti looked at patients with brain destruction localised to only one hemisphere of the brain, he noticed that those with harm to the kept hemisphere exhibited increased degrees of anxiety and hostility while those with right hemisphere damage appeared to show an indifferent or unemotional response. This led him to believe emotion was targeted in the right brain. Further research by Etcoff et al (1992) proved their members people both lying down and telling the reality. Etcoff pointed out that people that have right hemispherical harm were less in a position to determine who was lying and who was simply telling the reality while interestingly those with left hemisphere harm were better at detecting the liars than the control who possessed no brain harm. This business lead to the final outcome that the kept brain was analytical and would disregard misleading terminology and pay attention to subtle emotional cosmetic expressions to detect lays. While these studies indicate the right hemisphere being dominate when it comes to emotion it is possible that each part of the mind is specialised to either positive or negative feelings with the right focusing on negative and the left focusing on positive.
Lobes aren't completely unbiased; they contain sections known as connection areas. A link is an section of the cortex spread around each lobe that helps each lobe talk to each other. That is done by having, for example, a aesthetic connection area in the frontal lobe so the frontal lobe can determine where items can be found and what lengths away they are simply so that when controlling the electric motor functions with the ability to guide your side to the exact spot it needs to maintain to pick up whatever the thing is. These electric motor functions are handled by another sub section within the mind known as the motor cortex and somatosensory cortex, in any other case known as areas 4 and 6. Both of these areas are commonly described in illustrations of the cortical homunculus which is a pictorial approximation of the engine cortex and shows that areas requiring finer and even more precise activity requires more cortical space than those areas that happen to be instinctual replies. The electric motor cortex can be seen as being organized contra laterally with your body; this means that the most notable of the engine cortex deals with the bottom of your body and likewise the bottom of the engine cortex would offer with the top of your body.
Designs of the practical organisation of the mind as shown by the cortical homunculus illustration cannot be seen as entirely correct. The localisation model of the brain is seen as completely contradicting model which gives purely clinical data as is shown in patients that suffer harm to a lobe, for example a person with harm to the occipital lobe will probably suffer from visual agnosia or blindness, the localisation model would then therefore say that if an association area was ruined then it is likely that the sense or controlled mechanism would be similarly impaired from damage in this area. This contradicts Lashley's equipotentiality notion as Lashley's strategy indicate that damage to an association area would not automatically impair brain function whichever area of the brain that specialized in vision was damaged, it is because he believed that each area of the brain could do the job of every other brain area because of its elasticity. The challenge however with this model is that it was investigated on wild birds using ablation techniques (the removal of pieces of the cortex) whereas localisation research was done on humans. The trouble however with localisation research is that it was looked at too narrowly and experts were not taking a look at the brain all together but more the effect that a solo area had on the behavior of the patient.
The equipotentiality idea and localisation models resulted in the distributed function model of the brain, which really is a compromise between your two models as it shows both; how the brain can conform and re-organise itself in the event of harm, i. e. in case a lobe is broken the brain can 'rewire' itself to try and function. Also how in the event of absolute destruction (a sense being completely impaired) the brain can use more of its resources to give attention to another area including the use of touch or reading. Most importantly this model shows how several section of the brain is involved with making a mental mechanism work. At the same time this shows where the dominate control area for the system is unlike the equipotentiality idea which indicate the whole brain is responsible for the mechanism and the localisation model which would suggest only one point of the brain is responsible. Data supporting the distributed function model prevails in visual control, language and recollection this is apparent by using split brain studies and brain scan studies such as Tulving (1989). Tulving found that when his members used the pre-frontal cortex predominately to try to remember episodic stories while semantic memory exhibited high degrees of activity towards the trunk of the cortex. Tulving's findings were then backed up by Maguire et al. (1997) which found that taxi drivers would have high cortical activities in the hippocampus when remembering a road through London instead of remembering information about landmarks which showed low activity in the hippocampus. This shows how information can be localised to a specific cortical area at exactly the same time as being used in other places.
The main advantage of the allocated function model is that in case of brain damage it is possible that complete function loss may not appear as opposed to localisation which means that if a lobe was destruction function would be totally lost compared to that mechanism. This is shown regarding Phineas Gage when a tampering flat iron was influenced completely through his skull massively destroying his pre-frontal cortex, yet after making it through he persisted with a standard life, albeit in an alternative manner, as it was said that his friends no more observed him as Gage but as someone else.
The brain can further be described as using a cross system, this means that right aspect of the brain controls the remaining side of the body and vice versa, this as well as the lateralization of the brain can be shown by using break up brain studies. Sperry (1968) studied severely epileptic patients that could not control their seizures by using drugs. In such a test the corpus callosum (dense band of tissue that links the left and right brain over the central fissure of the brain. ) of the patients was severed, this effectively severed the links between your two halves of the mind localizing brain seizures to only one side of the brain, by stopping communication between the halves. This designed that the field of expertise of every hemisphere could be examined. Sperry did this by showing the patient a graphic in the kept spatial field, and then the right, when the same image appeared on the right the patient cannot recognise what it was, nevertheless the patient could write or illustrate it entirely. More interestingly if the individual was shown a graphic on the departed he could point to a matching object with his remaining hand but not his right. These both proves that every side of the mind is specialized to a particular function, the right being of the creative character and the departed of a rational nature.
Finally because of the complexity of the mind and our lack of understanding, it is impossible to fully determine which section of the brain relates to which mental process, to get this done we'd need to constantly keep an eye on a living brain in natural scenarios. Currently we can only just see efficient representations of the mind through use of scans such as PET's and fMRI's, this helps it be difficult to see how the brain responds to normal stimuli. Where we can see where in fact the brain reacts to stimuli is through the use of EEG's which strategy brainwaves, however this does not allow us to see precisely where in fact the brain is activated. Another method we can use is electrical arousal of the brain (ESB) which will try to stimulate stressed replies. Although this is a good method it is not exactly like a nervous impulse. Overall this makes it almost impossible to map the human brain exactly, while we do have harsh models these are broad and we cannot determine if the brain is further special beyond what we can easily see.