Neurotransmitters + aggression. Flashcards
Introduction. Aggression? What are neurotransmitters? High serotonin + low dopamine?
Aggression is a type of hostile which is usually inhibited by social norms.
Neurotransmitters are chemicals that enable impulses within the brain to be transmitted to one side of the brain to the other.
It is believed that our aggressive behaviour is influenced by the neurotransmitters.
There are two types of neurotransmitters: serotonin and dopamine.
Low levels of dopamine = aggression.
High levels of serotonin = aggression.
Serotonin. Emotional stimuli? Aggressive response?
Serotonin is thought to reduce aggression by inhibiting responses to the emotional stimuli which would otherwise lead to an aggressive response.
Whenever there are low levels of serotonin, there is an increase in impulsive behaviour which can lead to aggression or in some cases, suicide.
Drugs altering serotonin levels?
There are also drugs that can alter the levels of serotonin and therefore lead to an aggressive response.
Prefrontal cortex. Responsibility? Disturbed?
The prefrontal cortex is responsible for planning, reasoning and impulse inhabitation.
So, the prefrontal cortex is directly impacted on the persons behaviour which can cause the aggressive behaviour.
Low levels of serotonin can disturb the prefrontal cortex and calm the inhibited firing of neurones, therefore causing the aggressive behaviour.
Support research. Mann et al + dexfenfluramine?
Mann et al gave 35 patients dexfenfluramine which is a drug that decreases the levels of serotonin.
After, the participants were given a questionnaire and found that the drug which decreases serotonin levels was associated with the increase in aggressive behaviours.
Evaluation. Non animal study + Raleigh et al + Vervet monkeys + tyrophan.
Raleigh et al studies vervet monkeys and used tyrophan in their diets which increases serotonin.
Those who were fed high levels of tyrophan had decreased levels of aggression.
The low levels of tyrophan led to increased levels of aggression.
Evaluation. Anti depressants + serotonin + Bond.
Bond found in clinical studies, the anti depressant drug elevates the serotonin levels and intends to increase the irritability and impulsive aggression.
This shows how antidepressants can alter the serotonin levels and increase aggression levels.
Dopamine. Link? Amphetamines? Lavine + antipsychotics. Rewarding stimuli?
This link isn’t as strong as serotonin in regards to aggressive behaviours but there is still evidence of a link between the two.
It has been found that amphetamines increase the levels of dopamine and the drug has been associated with aggressive behaviours.
Lavine also found that found the use of anti-psychotics have reduced the activity of dopamine in the brain and therefore increased the aggressive behaviours.
Dopamine is known for producing a rewarding stimuli in someone and that rewarding stimuli can influence the aggressive behaviour.
Evaluation. Weakness + inconclusive.
There has been a weakness pointed out when looking into dopamine, the research has been found to be fairly inconclusive.
This can dispute the link between aggression and dopamine as the research isn’t conclusive enough to provide a link/
Evaluation. Coupiss + Kennedy + dopamine + consequence + mice + rewarding pathway.
They found that in mice, a rewarding pathway in the brain becomes engaged when they are in an aggressive event.
It was found that dopamine was a positive reinforce in the pathway; this suggests that people seek the aggressive behaviour because they want the rewarding experience.
Shows that dopamine may act as a consequence to the aggressive behaviour as it opens the door to the rewarding feeling.
