Biological Explanations - Neurotransmitter Imbalances Flashcards
What neurotransmitters are linked to aggression?
Dopamine and serotonin
What are the levels of dopamine and serotonin which are associated with aggression?
Low levels of serotonin and high levels of dopamine
What effect do normal levels of serotonin have?
A calming effect on the brain
What effect do low levels of serotonin have?
The inhibitory effect is removed, resulting in less control of impulsive and aggressive responses
Which part of the brain is most affected by levels of aggression?
The frontal cortex
How does the influence of serotonin on aggressive behaviour explain the relationship of alcohol and aggressive behaviour?
Alcohol consumption causes disturbances in the metabolism of serotonin in the brain, resulting in depleted serotonin levels which may induce aggressive behaviour
What studies are linked to neurotransmitter imbalances?
Mann et al
Ferrari et Al
What study is linked to serotonin?
Mann et al
What were Mann et al’s findings?
All participants were given dexfenfluramine (a drug which depletes serotonin levels in the brain). After completing a questionnaire, they found aggression and hostility levels were increased among males but not females.
Evaluation points for Mann et al’s study…
It is less socially desirable to admit aggressive traits, women may have been more susceptible to this
Lack of validity in behaviour as questionnaire results are subjective and doesn’t represent their actions - only what they say. This may lead to a lack of validity and in turn the explanation that low serotonin leads to aggressive behaviour is incorrect.
What are the explanations of serotonin and its affects on aggression?
Low serotonin levels cause an increase in levels of aggression
Increases serotonin receptors cause and increase in levels of aggression
How are serotonin receptors created?
When serotonin is chronically depleted the brain responds increasing the number of receptors
What is an example of dopamine and aggression?
Amphetamines increase dopamine levels in the brain and are often associated with increased aggression
What has been successful in reducing aggressive behaviour?
Dopamine antagonists (reduce dopamine activity)
What are dopamine antagonists?
Chemicals which reduce dopamine activity thus reducing aggressive behaviour
What study supports the influence of serotonin and dopamine in aggressive behaviour?
Ferrari et al
What were Ferrari et al’s findings?
On the 11th day, even though the rat did not fight, it was expecting to as a result of the previous ten days of fighting. This is clear as the rats dopamine levels had increased and the serotonin levels decreased. The change in brain chemistry illustrates a link between aggressive behaviour and serotonin and dopamine levels.
What does Ferrari et al’s study demonstrate?
It is not necessarily an innate baseline of neurotransmitters that causes aggression but an interaction with experience
What debate can be used for neurotransmitters?
Animal debate
What is the argument in favour of using animals in research?
We are morally obliged to ease human suffering thus can use animals for research to protect humans from harm. Evolution has places humans at the top of the phylogenetic tree so it is natural to make use of lower animals for our health benefit
What is the argument against using animals in research?
There are more modern techniques which can also assess levels of aggression on humans which dint result in harming animals e.g CT, MRI and PT scans
What are neurotransmitters?
Chemicals that allow impulses to travel between neurones
Who investigated the effects of dopamine on aggression?
Lavine
Mann et al
Who investigated the effects of amphetamines and aggression?
Lavine
Who studied alcohol and serotonin?
Badawy
