Animal studies have shown that high doses of dopamine aginists induce stereotyped movements in animals that resemble the compulsive behaviours found in OCD patients. Further evidence of dopamine can be found in patients with Tourette’s Syndrome, which are assoiated with the dopamine dysfunction in the basil ganglia. Between 45% and 90% of Tourette’s patients also have obsessions and compulsions. | One strength of the biochemical explanation of OCD is that it has practical applications. For example, Piggott et al.
Research by Geen & O’Neal (1969) suggests that noise may be more of a trigger to pre-existing aggression than actually causing it. They exposed participants to either an aggressive or non-aggressive film then gave them the opportunity to administer electric shocks to others. It was found that, when noise levels were elevated, the frequency of shocks increased. However, this was only in the group who’d watched the aggressive film. Donnerstein & Wilson (1976) conducted a similar experiment and found, if participants were given control over the noise, levels of aggression decreased.
Research into Kluver-Bucy syndrome supports these findings as humans with the syndrome, as a result of temporal lobe damage, become passive. This is attributed to damage to the amygdala. However, contradictory research from Wong et al (1997) suggests that reduced amygdala size leads to reduced activity in violent criminals. Ashford (1980) suggests that stimulation of the amygdala leads to intermittent explosive aggressiveness, as people with temporal lobe epilepsy become very aggressive. The prefrontal cortex is also part of the complex system of structures involved in aggression.
In terms of biochemistry, chemical imbalances in the brain may be involved in certain mental illnesses. Neurotransmitters, for example, play a very important part in behaviour – one theory links depression to low levels of the neurotransmitters serotonin and noradrenaline. However, the relationship between neurotransmitters and depression is very complex and therefore, more research is needed to discover the exact link between this and the disorder. People suffering from depression, also often have high levels of the hormone cortisol. Cortisol is sometimes referred to as a ‘stress hormone’ because it is produced in times of stress.
The prefrontal cortex is in charge of thought analysis and regulated behaviour. When the amygdala is over reactive, this is when aggressive behaviour occurs. Research supporting the role of the amygdala in aggression comes from Kluver and Bucy (1930). They removed part of the temporal lobes of rhesus monkeys (thus destroying their amygdala). The behaviour changes resulting from this procedure included a loss of fear and a marked taming effect, therefore a reduction in aggression.
There could be some damage to the central nervous system but not very severe or the symptoms that Nick exhibits would be more severe. C. Diabetic neuropathies damage peripheral nerves. Which component of the reflex arc is most likely to be damaged in Nick’s situation? The component of the reflex arc that is most likely to be damaged in Nick’s situation would begin at the sensory neuron. Stimuli is still triggering the receptor but the information from the sensory neuron doesn’t continue the arc to the integrating centers to the motor neurons to the effectors which causes the absence of a reflex.
These issues are more related to chronic stress rather than acute stress and it occurs for a long period, thus affecting health for a longer period. There is a considerable amount of research conducted on this topic, for example, stress affecting the digestive system and leading to gastric ulcers. One of these studies was conducted by Brady, in which he wanted to investigate whether the stress of receiving electric shocks lead to stress-related illnesses and whether this would change with the degree of control over the shocks. The monkeys received foot shocks which were signalled by a tone, these monkeys were run in pairs, one of them was called the “executive monkey”, which was able to press a level to avoid shocks. The other was the “yoked” animal, which did not have the lever and received all the shocks anyway.
This weakens the immune system leaving the body vulnerable to infection and illness. Raised levels of cortisol suppresses the TH1 immune response. Kiecolt-Glaser et al conducted a natural experiment into acute stress, the aim was to see if the stress of exams had an effect on the immune system. Blood samples were taken from medical students before and during the exam period, T-Cell activity was measured in the blood samples. The findings showed that T-Cell activity was significantly higher before exams which suggests that acute stress caused reduced immune system functioning.
Clinical and anatomincal studies compare what people could do before their brain damage with what they can do afterwards. For example the case study of Phineas Gage in 1848 whereby an iron pole ripped out his pre-frontal lobe as a consequence of an explosion while working on the railways. This damaged his personality from being a sensible, kind and reserved to someone who was now boisterous, lazy and rude. This case study taught psychologists a great deal about the complexity of psychological processes that occur in the human brain. However a limitation of this study is that the sample size is small so would be difficult to generalise because of individual differences in humans.
It is called the FAST test: F= Facial weakness A= Arm weakness S= Speech problems T= test all 3 signs and call 999 2.4 Describe the potential changes that an individual may experience as a result of stroke. Some of the physical changes that occur in the individual after suffering a stroke are psychological, behavioural and emotional changes take place after a stroke are in part caused by the physical damage to the brain. When the brain cell is damaged the sensations and parts of the body controlled by the cells can no longer function