Describe and Evaluate Neural Mechanisms Involved in Aggression

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Normal aggressive behaviour involves an interaction of a system of structures, as opposed to being dependent on separate brain structures. One part of this system is the Amygdala. This is a structure inside the temporal lobe which, plays an important role in the mediation of affective activities and on the expression of mood; mainly fear, rage and aggression. The amygdala is connected to many structures in the brain including the hippocampus, thalamus and pre frontal cortex. It is fundamental for self-preservation as it enables the identification of danger; therefore exhibiting clear links to aggression. Despite research on the amygdala, the exact role is still unknown. Narabyashi et al (1972) found that 43 out of 51 patients, whose amygdala was destroyed, showed reduced levels of aggression. This supports the role of the amygdala in aggression. 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. This part of the brain regulates the emotional responses driven by the amygdala. It is responsible for executive cognitive processes and also moderates behaviour and allows one to understand the consequences of their own behaviour. Fallon argues the prefrontal area, specifically the orbital cortex, is implicated as it regulates social functions such as ethics and morality. He believes this area is broadly involved in inhibiting behaviour. As a
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