- heres a couple i have done, not perfect but hope it helps! would defo google specific essays that you need and stuvia is usually comleted them already to give you a guidline. there are 16 markers at the end of each topic page in the texbook so make your way through those xxx
Localisation is the theory that different areas of our brain are responsible for different behaviours and activities, proposed by broca and Wernick. Our brain is divided into two parts ; the right and left hemisphere, some of our physical and psychological functions are controlled by particular hemispheres (lateralization). Activity on the left hand side of the body is controlled by the left side of the body and vise versa the cortex of the brains hemisphere is subdivided into four lobes; frontal,occipital,temporal and peripheral, each lobe is associated with different functions.
Firstly, the motor area is located in the frontal lobes of the brain, this area is responsible for voluntary movements in the opposite side of the body. The somatosensory area is located in the parietal lobes. This area is where sensory information from the skin is represented. The visual area is located in the occipital lobe an is responsible for processing visual information. Lastly, in the temporal lobe is the adultery area, this is responsible for analysing speech based information, damage to this area may cause partial hearing loss.
Other important areas of the brain are located in the left hemisphere, called language centres. Broca's area is located in the left frontal lobe and is responsible for speech production. Damage to this area will result in broca's aphasia which is characterised by slow speech and lack of fluency. Whilst, wernicke's area is responsible for speech comprehension and understanding, located in the temporal lobe. Damage to this area will result in wernicke's aphasia, characterised by ability to speak but not understanding and often produce nonsense words.
A strength of localisation is that brain scans support that many neurological functions are localised, particularly in relation tion to memory and language. For example, peterson found, using brain scans, that wernicke's area was active during a listening task and brocas area was active during a reading task. These suggest that these ares are infact distinct and separate as they are active during different tasks an hat many functions are localised. Thus, this increases the external validity of localisation of the brain objective scientific evidence supports it.
Another strength of localisation is that case studies support this theory too. For example, the case of phineas gage who suffered from an accident, which resulted in a metal pole existing his skull taking most of his brain and left frontal lobes. This case study supports localisation as damage to the brain resulted in him having a change of behaviour and personality as the frontal lobe was damaged. Howver, this study lacks external validity as case studies are unique one off cases and everyone's brain may differ, thus, we are unable to generalise the findings from this study to the wider population.
Alternatively, a limitation of localisation of function is that it fails to consider individual differences. For example, herasty found hat females have proportuonally larger broca and wernicks area, which can explain the greater ease of language use amongst woman. Thus, we are unable to generalise research examining localition of functions to males and females equally as the different brain sizes and structures suggests there different considerations are required when considering different sexes.
Finally, critics ague that theories of localisation tion are biologically reductionist in nature, and try to reduce very complex human and cognitive processes to one specific area of the brain region. Such critics suggest that a more thorough understanding of the brain is required to truly understand complex cognitive processes/
Plasticity and functional recovery
Plasticity is the brains tendency to change and adapt, functionally and physically, as a result of new experience and learning.research suggests that the brain continues to create new neural pathways and adjust current ones as a result of new experiences. As we get older, the synaptic pathways we don't use are removed and the ones we do are strengthened, through a process called synaptic pruning.
One research into plasticity was conducted by kuhn et al, he found an increased in grey matter in various regions of the brain as a result of participants playing 30 minutes of video games over a two month period. Whilst davidson et al demonstrated the permanent change in the brain due to meditation; buddhist monks who frequently mediated had greater activation of gammer ways (correlates to neural activity) compared to a control group who had not experienced mediation. These studies show the permanent changes in the brain as a result of continued experience of a new task.
Morver, maguire et al also showed plasticity in action. Maguire et al found that the posterior hippocampal volume of london taxi drivers positively correlated to their time as taxi drivers and that their were significant differences between their brains against a group of controls. This therefore demonstrated the changes in the brain in response to frequent exposure of tasks. However, psychologists criticises maguires research and claim it is severely flawed. This is due to maguire et al not testing the individuals brains before they became taxi drivers as they could have had larger hippocampus before their experience as drivers. Therefore a cause and effect relationship between changes in the brain and experience can not be established.
Researchers have also highly investigated functional recover, a type of plasticity. This is the brains ability to transfer functions from damaged areas of the brain as a result of truma to undamaged areas of the brain to continue functioning. One way in which this occurs is neural unmasking, this is when dormant synapses (synapses that did not receive enough input) become activated and take on the functions of nearby damaged areas to allow the brain to contain functioning. This is often paired with different structural changes in the brain such as axon sprouting. Functional recovery can occur quickly after truma (spontaneous recover) and slow down after weeks or months, at this point therapy may be needed. Stem cells are also used in aid of functional recover, these are used as a way of recovering function in the brain. these are unspecialised cells that can take on the characteristics of nerve cells, allowing the brain to create new neural pathways and recover any damage to any existing cells that may otherwise prevent effective neurotransmission.
A strength of functional recovery is that it is supported by animal research, by Hubel and weasel. This involved sewing one eye shut of a kitten and analysing the brains cortical response. It was found that the area of the visual cortex associated with the shut eye was not idle, but continued to press information from the open eye. therfore increasing the reliability of functional recover. however there is question on weather this study can be generalised to humans, due to the use of animals. this is becasue humans have greater developed brains and therefore the ability of functional recovery may differ greatly from that found by hubel and weisel.
Psychologists have found that functional recovery may deteriorate with age. For example elbert et al concluded that the capacity for neural reorganisation is less effective in older brains. this may explain why adults find change more demanding they young people do. Therefore we must consider individual differences when assessing the likelihood of functional recovery in the brain after trauma