Adult brains show localized functions, for example with speech processes being concentrated in areas in the left hemisphere and with executive functions concentrated in the pre-frontal cortex. How does this organization come about? Is it because these fu

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Adult brains show localized functions, for example with speech processes being concentrated in areas in the left hemisphere and with executive functions concentrated  in the pre-frontal cortex. How does this organization come about? Is it because these functions are localized from birth?

Brain processing has been in scientists' focus for many decades. As much as they have learned about brain and its functioning through studies and experiments it still does not answer all the questions. With the help of modern technology such as brain imaging, MRI and other, we are now able to understand much more about brain functions. But some questions at the heart of all the brain functioning still remain and research continues into exploring the links of cognitive functioning of the cortex.   I would like to focus on two different approaches that attempt  to .explain the localized functioning in the brain, the innate modularity and modularization, and how this organization is believed to have come about.      

Cognitive development of the brain starts in the pre-natal phase when the brain development may be affected by the environment which is rather limited. Therefore the post-natal period of the brain development is considered more important. Human brain is designed to mostly develop after the birth and most of the brain maturation happens then. The distribution and multiplying of neurons in the brain peaks at about 24 months after the birth. (Mareschal et al., 2004, p. 122)

During this time brain posses the ability of plasticity that allows for adaptability of different parts of the brain. At this time plasticity determines that the functions in the brain are not yet specified  as this ability allows for different parts of the brain to able to take on different functions in cases of localized brain damage. In adults, brain is far less plastic and therefore any brain damage is much more difficult to overcome.  The more the brain matures the more are its neural pathways separated and functions localized and therefore it is more difficult for the brain to 'transfer' functions from one part of the brain onto another.   Different parts of the brain are 'assigned' with particular functions such as language and speech is located predominantly in the left hemisphere and cognitive functions in pre-frontal cortex. (Mareschal et al., 2004, p. 123)    

 

Along with the brain maturation and the separation of neural pathways in the brain comes the functional specialization. Studies that support this claim carried out by Lewkowitz and Turkewitz (1981) in the early 1980s showed that newborn infants visual preference was affected by prior auditory stimulus. Also the studies by Meltzoff and Borton (1979) show that independent pathways in infants between 3 and 5 months of age are used to receive information from different senses. These processes of separating neural pathways to create a localized functioning of the brain are linked to 'selectionism' which derives from Darwin's theory of selection, in this case showing that the pathways no longer needed are eliminated and those that are needed and in frequent use get strengthened in order to function with less effort and more quickly. Though this process is not well understood though and involves some speculation. (Mareschal et al., 2004,

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p. 124-5)

One way of trying to understand the structures and functioning of the brain is dividing the brain into cognitive modules. As much as there is an ongoing speculation whether cognitive modules exist, they do offer a basis for possible explanation of brain functioning. Two contrasting theories explain the brain functioning from different perspectives particularly how the cognitive modules develop. First of them is Innate modularity argued from the nativist point of view by Fodor (1983).  He argues that modularity of the brain is innate, humans are born with 'pre-fabricated' brain's ability to function in a particular ...

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