localisation of function

• Location of function is that specific functions have specific locations within the brain. The motor cortex is for voluntary motor movements. Its in the front region of the brain along the precentral gyrus. In both hemispheres, each controlling the opposite side to where it is situated. They are located logically eg, region that controls the foot is next to the one that controls the leg. The somatosensory cortex is sensory events. In the parietal lobe of the brain, along postcentral gyrus. It produces feelings from sensory info such as pain. In both hemispheres, also controls the opposite side.
• There are also the visual and auditory centres. The visual centre is found in the visual cortex in the occipital lobe of the brain. The visual processing begins in the retina, then transferred from nerve impulses to the occipital lobe. The visual cortex is in both hemispheres, input from the left eye is processed in the right hemisphere and vice versa. The auditory centre, most of this area lies within the temporal lobes on both sides of the brain. Nerve impulses travel via the auditory nerve to the auditory cortex.
• . The language centres are another part. Broca’s area was found by Paul broca who treated the patient ‘Tan’ who could only say tan. Tan could understand language, but not speak. More patients with this were also found, who had damage to their left frontal hemispheres. This lead them to the language centre. This is in the posterior portion of the frontal lobe, critical for speech production.
• Shortly after Brocas area was found, Wernicke’s area discovered speech production. This was involved in understanding language. This is in the posterior section of the left temporal lobe. Individuals with lesions in this section could speak but not understand. The sensory region in wernicks area is close to regions of the brain responsible for auditory and visual input.
• Not all researchers agree with localisation of the brain. A researcher believed that basic motor and sensory functions were localised, but that higher mental functions were not. intact areas of the cortex could take over responsibility for specific cognitive functions following injury to the area normally responsible for that function. According to this, the effects of damage to the brain is due to the extent rather than the location. This view has received some support from the discovery that humans were able to regain some of their cognitive abilities following brain damage.
• Dronkers et al. (2007) re-examined the preserved brains of two of Broca's patients, Louis Leborgne (Tan) and Lazare Lelong. They used modern high-resolution brain MRI imaging in order to identify the extent of any lesions in more detail.

  The MRI findings revealed that other areas besides Broca's area could also have contributed to the patients' reduced speech abilities. This finding is significant because although lesions to Broca's area alone can cause temporary speech disruption, they do not usually result in severe disruption of spoken language.
• Evidence for the different functions of Broca's and Wernicke's areas comes from the discovery that damage to these different areas results in different types of aphasia.

  Expressive aphasia (Broca's) is an impaired ability to produce language. in most cases, caused by brain damage in Broca's area. Receptive aphasia (Wernicke's) is an impaired ability to understand language, from spoken or written words. This form of aphasia is usually the result of damage in Wernicke's area.

  This demonstrates the important role played by these brain regions in different aspects of language.
• Research suggests that how brain areas communicate with each other is more important. Wernicke claimed that although different regions of the brain had different specialist functions, theyre interdependent. For example, in 1892 a neurologist described a case in which the loss of an ability to read from damage to the connection between visual cortex and Wernicke's area.

  This suggests behaviours such as language and reading are built up gradually. Damage to a connection between any two points in the process results in impairments that resemble damage to the localised brain region.