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Psychology - Aggression (NEURAL AND HORMONAL INFLUENCES (EVALUATION…

- - - - The Amygdala - This is responsible fr quickly evaluating the emotional importance of sensory information and prompting an appropriate response. If certain areas of the amygdala are stimulated electrically, an animal responds with aggression, for example snarling and adopting an aggressive stance. If the same areas are surgically removed, the animal no longer responds to the stimuli that would have previously led to rage. For example, Kluver and Bucy (1937) discovered that the destruction of the amygdala in a monkey who was dominant in a social group caused it to lose its dominant place in the group
      - The Hippocampus - This is involved in the formation of long-term memories, and so allows an animal to compare the conditions of a current threat with similar past experiences. For example, if animal had previously been attacked by another animal, the next time they encounter that animal they are likely to respond either with aggression or fear, whichever is more appropriate. Impaired hippocampal functional prevents the nervous systems from putting things into a relevant and meaningful context, and so may cause the amygdala to respond inappropriately to sensory stimuli, resulting in aggressive behaviour. For example, Boccardi et al (2010) found that habitually violent offenders exhibited abnormalities of hippocampal functioning
      - Serotonin - In normal levels this exerts a calming, inhibitory effect gonna neural firing in the brain. Serotonin typically inhibits the firing of the amygdala, the part of the brain that controls anger, fear and other emotional responses. Low levels of serotonin remove this inhibitory effect, with the consequence that individuals are less able to control impulsive and aggressive behaviour. As a result, when the amygdala is stimulated by external events, it becomes more active, causing the person to at on their impulses, and making aggression more likely. Serotonin is also thought to reduce aggression by inhibiting responses to emotional stimuli that might otherwise lead to an aggressive response. Low levels of serotonin in the brain have been associated with an increased susceptibility to impulsive behaviour, aggression and even violent suicide. Some drugs are though too alter serotonin levels and thus increase aggressive behaviour. Mann et al (1990) gave 35 healthy participants dexfenfluramine, which is known to deplete serotonin. Using a questionnaire at access hostility and aggression levels, they found that dexfenfluramine treatment in males (but not females) was associated with an increase in hostility and aggression scores