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20 Cards in this Set
- Front
- Back
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Definition of neurotransmitters |
Endogenous chemicals that allow nerve impulses in one area of the nervous system to be transmitted to other areas |
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Contextualise neural mechanisms |
Part of the biological model alongside genetic inheritance and hormonal mechanisms, all of which emphasise internal rather than external factors |
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Aggression linked to biochemical imbalances |
low levels of serotonin, high levels of dopamine |
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AO1 Serotonin |
-Cases have shown that serotonin in normal levels exerts a calming inhibitory effect on neuronal firing in the brain - Low levels of serotonin in prefrontal cortex remove this inhibitory effect so that individuals are unable to control their impulsive and aggressive responses - Can test this by correlation analysis or by an experiment |
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Brown AO2 Serotonin |
-Take sample of cerebrospinal fluid of people who display aggressive behaviour naturally occuring - work out serotonin level against aggression level (should see a negative correlation) - Correlation does not prove causation |
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Brown (Explicit AO2) Serotonin |
This supports the effect of neurotransmitters on aggression as the lower the serotonin levels in the cerebrospinal fluid the higher the aggression level |
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Mann AO2 Serotonin |
-Administered dexfenfluramine to 35 healthy adults -Drug depletes serotonin levels in the brain - Used a questionnaire to asses hostility and aggression levels -Found males aggression levels increased after taking the drug |
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Mann Explicit AO2 Serotonin |
This supports the effects of neurotransmitters on aggression as Mann found that amongst males aggression levels increased after taking the drug and as it was an experiment Mann's approach shows causation. However manipulating serotonin levels knowing it can lead to aggression raises ethical issues |
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Alternative Explanations AO2 Serotonin Arora & Meltzer |
-May not be caused by low serotonin levels but by low serotonin metabolism which leads to an increase in receptors - Arora & Meltzer relationship between violent suicides and elevated serotonin receptor density in the prefrontal cortex -Mann amongst people who had committed suicide those with increased number of pre frontal cortex receptors |
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Alternative Explanations AO2 Serotonin Mann |
-Amongst those who had committed suicide those with increased numbers of pre-frontal cortex receptors chose more violent methods of suicide -Explicit AO2 This supports the importance of serotonin levels in aggression but criticises the theory that the relationship is simply about serotonin levels |
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Alternative Explanations AO2 Serotonin Badawy |
Alcohol consumption depleted serotonin levels in normal individual when drunk acutely. In susceptible individuals this depletion may induce aggressive behaviour. This supports the importance of serotonin levels as when they are too low aggression is more likely although the relationship is complex |
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Dopamine AO1 |
- Link between dopamine and aggression is not as established at serotonin - increase in dopamine activity - one way to study the effect of dopamine is on antagonists (reduce dopamine activity) - dopamine is produced in response to rewarding stimuli, food, recreational drugs -One theory is that some individuals seek out aggressive encounters because the increase in dopamine creates a rewarding sensation |
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Lavine AO2 Dopamine |
Increases in dopamine activity via the use of amphetamines are linked to an increase in aggressive behaviour. This supports the importance of dopamine on aggression as the higher the levels of dopamine there is an increase in aggression. |
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Buitelaar AO2 Dopamine |
Found that the use in dopamine antagonists which reduce the dopamine activity in the brain reduced the aggressive behaviour in violent delinquents. This supports the importance of dopamine as the lower the dopamine levels aggression is lowered |
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Couppis AO2 Dopamine Supports |
Found that dopamine plays an important reinforcing role in aggression. This supports the theory that some individuals intentionally seek out aggressive encounters because of their rewarding sensations caused by the increase in dopamine which these encounters provide |
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Couppis AO2 Dopamine Criticism |
-Hard to establish link dopamine and aggression - Turn off dopamine in mice makes it difficult to move This criticises the importance of dopamine as a subsequent drop in aggressive behaviour when dopamine levels are decreased could be due to a lack of motivation or de to the mice finding it difficult to move and so finding it difficult to respond aggressively |
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Ferrari et al AO2 Dopamine & Serotonin |
-rat to fight for 10 days at same time -11th day not allowed to fight measured lebels of serotonin and dopamine in the brain -anticipation of imminent fight changed the animals brain chemistry by lowering levels of serotonin and increasing levels of dopamine |
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Ferrari et al Explicit AO2 |
This supports the role of neurotransmitters in aggression as when prepared to be aggressive the mice's levels of serotonin were low and dopamine high. However this was a study on non human animals and so results cannot be generalised to humans. It also raises ethical issues on the well being of the mice |
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Criticism of neurotransmitters causing aggression |
We are assuming that it is the change in brain chemistry affecting aggression but it may be that aggression is affecting brain chemistry. |
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Conclusion |
- Criticised for being reductionist, reduce complex human behaviours to a biochemical level, and deterministic, behaviour is solely controlled by our bio-chemistry - Many of the studies are on non human animals so cannot assume findings can be applied equally to humans/raise ethical issues -Criticised by social psychological viewpoint as it ignores role of external factors - Both biochemical imbalance explanations are well supported by empirical data from a range of methodological approaches and so make an important contribution to our understanding of aggression |
