Tma 02 - Psychology Case

TMA 02

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. (OPTION B)

The subject of this essay is to describe cases where brain isn't functioning normally and how this relates to particular human behaviours.

Everything that we feel or do is commanded and stimulated by the brain. Brain and nervous system collects and "translates" impulses from the environment and transforms them into an information, which is used to manipulate our behaviour accordingly to the situation. The main role in this "translations" play neurons and synapses. Synapses are the tiny junctions between brain cells (neurons) playing a role of communication field between them, allowing neurotransmitters (chemical substances used to assign, adjust and convert signals between a neuron and another cell to "travel" between cells. Any dysfunction to synapses results in lack or loss of ability to learn, think or plan (Society for Neuroscience, 2009). There are around one hundred billions of them by the time we reach the age of 21 and they are connected and grouped into a network called neural network, or neural system. (Wikia Education 2010).

Brain is a very complex structure and even a small amount of damage can cause catastrophic changes. Brain damage, or brain injury causes disruption of brain activity. It results in destruction or degeneration of brain cells that could occur due to a number of conditions, illnesses or injuries. Widespread brain damage could be caused by prolonged hypoxia (shortage of oxygen), poisoning, infection, or neurological illness. Causes of local or localized brain damage could be a physical trauma (Traumatic Brain Injury - TBI), stroke, aneurysm, or neurological illness. Another type of brain injury is Acquired Brain Injury (ABI), which occurs after birth and it's not congenital or degenerative (Brain Injury Association in Minnesota).

In case of the brain injury, the cells suffer a damage and many connections are mutilated, as there are always more connections than neurons. This damage is directly connected and responsible for changes in person's behaviour, physical and emotional restrains and it's a cause of cognitive difficulties. (Wikia Education 2010).

In many cases, we can observe behavioural changes as a result of brain surgery , what have been confirmed comparing the patients behaviour before and after surgery. It could result in brain damage and cells dysfunction (for example removal of cancerous tissue), but in some instances it could develop a positive development, like in case of epilepsy, when the brain is electrically stimulated. It improves the condition, but at the same time, the procedure might trigger some side effects, like difficulties in gathering and interpretation of the information by the brain. Penfield and Rasmussen concentrated on biological bases of memory in their research. Electrical stimulation of different parts of brain, during the brain surgery, brought back powerful images from the earlier times of life (as cited in Toates, 2007).

The Phineas Gage case (Toates, 2007), where the damage of his frontal lobes, following an accident, resulted in extensive changes to his personality is a very good example of how the brain injury reflects on the mental condition.

Disruptions are a chemical instability caused by underproduction or malfunction in manipulation of certain neurotransmitters. Such a state could be initiated by a disease, such as Parkinson's disease, where some of the neurons are damaged and others have limited abilities to absorb the neurochemical (in this case - dopamine) (Toates, 2007).

The researches focused on drugs abuse (such as nicotine, alcohol, heroin and cocaine) revealed, that the drugs change the behaviour of synapses. For example cocaine block the process of deactivation of the neurotransmitter (dopamine). Reduction of dopamine causes dysphoria (negative mood) and creates coveting for more cocaine with intention to recreate the feeling of pleasure. The drug stimulates the brain activity making a cocaine intake a habit, affecting parts of the brain responsible for emotion, motivation, pleasure and cognition. (Toates, 2007)

Although using the drugs is connected with biological causes of behavioural changes, there is no one-to-one link between drug and a mental state of the person. To be able to assess those effects, we need to take into consideration the whole nervous system and how consciously aware the person is. The same drug can have completely different effect on another individual. Some antidepressants have to be induced repeatedly for a period of time (like psychoactive heroin or cannabis) and surrounded by befitted social context, as they don't have the same effect on everyone. (Toates, 2007)

P. D. Wall (as cited in Toates, 2007), described an important psychological effect called a "placebo effect". It has been observed on some of the patients using morphine to relief the pain. A number of patients feel a pain relief while given an inert substance unwittingly instead.

In case of depression, there is a dilemma about whether it is genetic (biological) or a social disruption. Although Prozac proved to be an efficient drug in treatment of depression, what would suggest that stimulating synapses and therefore indicated it's biological source, however the stress, traumas or other environmental factors would infer a social background for a depression. (Toates, 2007). Depression is a very controversial disease and, depending on factors and biological predispositions of an individual, some people are vulnerable to different types of the depression than others. Current research allowed recognition of psychological causes like low-esteem, anger, pessimism, vulnerability and others. With medical conditions such as Parkinson's and Alzheimer's disease, cancer and many others, depression might appear as a secondary. Also, prescription drugs or substance and alcohol abuse contributes towards depression in many cases. (Clinical Anxiety Depression Help)

In conclusion, we can see, that change in a behaviour is not only caused by physically