Explain, with examples, how studies of brain damage or disruption to normal brain activity have informed us about the relationship between brain activity and behaviour in normal functioning.

us and to what extent they can explain the relationship between brain activity and behaviour in normal functioning.Biological Psychology assumes that all aspects of our Psychology stem from the activity of neuronal systems in the brain. Each Neural system works to perform a specific function, subsequently when studying abnormal behaviours the neural systems are of particular interest as it may be the breakdown or malfunction of the particular system impacts on particular behaviours.   Neural systems are made up of neurons, being cells specifically designed for processing information. A group of neurons together combine as a neural system, with each system having a specific function. The neurons process information by way of passing through a synapse (the gap between cells) and being received by the next neuron. The biology of the nervous system and brain activity is complex and requires a much more in depth explanation for full understanding but within this essay I will not cover in detail and question how it works but accept that it   does.Physical damage to the brain from injury, generally referred to as lesions, have taught a lot with regard to changes in behaviour. One famous case is that of Phineas Gage (Toates, J p268), who in 1848 suffered horrific injury when a tamping iron passed completely through his brain. Surprisingly Gage managed to survive this accident although he did suffer extensive brain injury. It appeared that little change occurred in his ability to function thereafter, however it was noted that his behaviour changed quite dramatically and was not as he had been previous to the accident. According to Damasio (1996) Gage showed a defect in his capacity to utilize emotional information concerning the more remote consequences of his actions. In summary he became obstinate and foul mouthed. Recent evidence shows that the frontal lobes inhibit emotional expression and therefore the damage caused disrupted this inhibition resulting in the abnormal and changed behaviour. The difficulty in understanding the effects and impact of damage to the brain is that they are usually unique accidents varying in specific damage. Therefore to compare resulting behaviours is difficult and environmental influence on each individual case not known.Important advances in technology have brought about new ways of observing brain activity. Positron emission tomography (PET) allows the brain to be scanned by non-invasive methods showing the brain while functioning and during activity. Through flow of blood the scan reveals where the greatest activity is by monitoring the most active neurons (chemical tracers are used to show this, the more a neuron works the more it consumes and therefore requires the blood flow). This technology allows for experiments to be conducted with participants performing various tasks and the regions of brain activity analysed – the same experiments could then be conducted on someone with a brain lesion perhaps then showing which behaviours and results observed with an undamaged brain, have been effected by the particular lesion. This allows Psychologists to investigate whether therapy may be of assistance to manipulate or improve the resulting behaviours and similarly make generalisations about the function of specific areas of the brain with regard to specific behaviours.Another cause of disruption or damage to the nervous system is the consumption of drugs, whether these are recreational or prescription. Prescriptiondrugs may be given to assist or improve an impaired behaviour by targeting particular types of synapses changing the way information is processed by the brain. For example somebody showing signs of obsessional neurosis could have the neuron system specific to our feelings of fear, manipulated by chemical intervention to reduce it’s activity and subsequently reduce the feeling of fear (as cited by Toates, p259)Depression is a behaviour where current theories suggest that specific neural systems such as the dopaminergic have abnormalities in neurotransmission. It is argued that a combination of genes can make an individual predisposed to depression giving abnormalities in the density of receptors at a specific synapse, this appears to be evidenced by the effectiveness in some cases of using drugs such as Prozac to target these receptors, however it is also known that exposure to sever stress or trauma can result in depression, therefore as an illness it is better to consider as both biological and social and a combination of both is required.In conclusion, the ability to analyse brain activity by both invasive and non-invasive methods has allowed researchers to find out which areas of the brain are responsible or at least involved in specific behaviours. The advancement of technology has allowed brain scanning to help pinpoint the level of activity within the brain while performing specific functions – therefore the ability to compare between a normally functioning brain and that of which has suffered either damage or disruption is possible and able to provide us with theories of the impact such damage has on human behaviour, however it is still difficult to put any such changes down to just biological influences as the social impact should never be ignored therefore a behaviour itself should be thought of as both biological and social.Word Count: 1026References:Toates, F. (2007). Biological processes and psychological explanation. In D. Miell, A. Phoenix, & K. Thomas (Eds.), Mapping Psychology (2nd ed., pp. 225-283). Milton Keynes: The Open University.