Neural Mechanisms - Biochemistry Flashcards
What NTs are linked to aggression?
High levels of dopamine.
Low levels of serotonin.
Abnormally high levels of serotonin.
Levels deviate and fall outside on a range, with serotonin.
Outline serotonin.
A NT that has a widespread inhibitory effect on the brain.
It slows down and dampens neuronal activity.
Normal levels of serotonin in the OFC are linked with reduced firing of neurons, and this is associated with a greater degree of behavioural self-control.
Outline Denson et al’s study from 2012.
(Supports the relationship between aggression and low levels of serotonin)
Supports the relationship between aggression and low levels of serotonin.
This is because they found decreased serotonin disturbs the mechanism, reducing self-control and leading to an increase in impulsive behaviour including aggression.
This suggests that there are biochemical explanations for aggression.
This is supported by patients with OCD, as they experience a reduction in serotonin which also leads to impulsive behaviour.
Outline Bond’s study from 2005.
(Supports the relationship between aggression and low levels of serotonin)
Supports the relationship between aggression and low levels of serotonin.
This is because they found lower levels of serotonin to be found in children and adults prone to violence.
This suggests that there are biochemical explanations for aggression.
Outline Mann’s study from 1990.
(Challenges the idea that the relationship between aggression and low levels of serotonin is universal)
Challenges the idea that the relationship between aggression and low levels of serotonin is universal.
When levels of serotonin were artificially reduced by a drug participants responses to a hostility and aggression questionnaire were increased.
However, this was not seen in female studies, suggesting there may be gender differences in biochemistry that affect the genders.
Outline Berman et al’ study from 2009.
(Supports the relationship between aggression and low levels of serotonin)
Supports the relationship between aggression and low levels of serotonin.
This is because when they gave PPs either a placebo or paroxetine (drug which increases serotonin), and were asked to give electric shocks of varying intensity in response to provocation - the group that took paroxetine consistently gave fewer and less intense electric shocks compared to the placebo group.
However, this was only true of PPs who had no history of aggressive behaviour.
Nevertheless, this study is useful evidence of a link between serotonin function and aggression that goes beyond correlational findings.
Outline Ferrari et al’s study from 2003.
(Supports the relationship between aggression and low levels of serotonin and high levels of dopamine)
Supports the relationship between aggression and low levels of serotonin and high levels of dopamine.
This is because when they conducted an experiment that forced rats to fight at exactly the same time every day for 10 days; on the 11th day the rats levels of serotonin and dopamine was measured in their brain, finding that the serotonin levels had decreased and levels of dopamine had increased.
This demonstrates that consistent aggressive behaviour can alter brain chemistry.
Outline dopamine.
The chemical that mediates pleasure in the brain.
It is released during pleasurable situations and stimulates one to seek out the pleasurable activity or occupation.
This means food, sex, and several drugs are also stimulants of dopamine release in the brain, particularly in areas such as the nucleus accumbens and prefrontal cortex.
Outline Lavine’s study from 1997.
(Supports the relationship between aggression and high levels of dopamine)
Supports the relationship between aggression and high levels of dopamine.
This is because they found an increase in dopamine activity via amphetamines was associated with increases in aggressive behaviour.
This suggests that there are biochemical explanations for aggression.
Outline Buitlaar’s study from 2003.
(Supports the relationship between aggression and high levels of dopamine)
Supports the relationship between aggression and high levels of dopamine.
This is because antipsychotics, (reduce dopamine activity in the brain) have been shown to reduce aggressive behaviour in violent delinquents.
This suggests that there are biochemical explanations for aggression.
Evaluate ‘much research involves non-human animals’, as a biochemical explanation of aggression.
Extrapolations are weak as many animals do not share the same brain structures as humans.
Many ethical considerations when using animals in research.
Reduces validity.
Evaluate ‘drugs’, as a biochemical explanation of aggression.
Drugs can have other effects on the body.
E.g. sleep, depression, OCD, schizophrenia.
Significantly reductionist.
Not holistic, instead take into different explanations of human behaviour.
Evaluate ‘using biochemistry is biologically deterministic’, as a biochemical explanation of aggression.
There is a focus on nature, more than nurture.
Doesn’t consider other human characteristics.
Presents aggression in a negative way.
Lacks free will.
Evaluate ‘implications on the legal system’, as a biochemical explanation of aggression.
Case of Stephen Mobley.
Case study of Abdelmalek Bayout.
Undermines the legal system.
More people likely to commit and appeal if there is a chance of getting away with crimes.
Evaluate ‘dopamine and serotonin in other behaviours/ conditions’, as a biochemical explanation of aggression.
OCD: antipsychotics, reduce levels of dopamine in order to treat OCD.
