P3: Aggression Flashcards
What is the limbic system?
Structures in the brain thought to be closely involved in regulating emotional behaviour including aggression.
What is the limbic system made up of? HAT Hipp
Hypothalamus, Amygdala, Thalamus and the Hippocampus
What does the reactivity of the amygdala play an important part in?
In how mammals assess and respond to an environment, predicts aggressive behaviour. The more responsive the amygdala the more aggressive the person.
What does the Hypothalamus do?
Regulates body systems.
What does the Thalamus do?
Associated with regulation of aggression. Thought to be part of a relay system with the amygdala.
What does the Hippocampus do?
Knowledge of how to react in certain situations, helps us determine whether aggression is appropriate.
What was Gospic’s study and how can it be used as evidence for the limbic systems role in aggression?
Lab study to test aggression using the ultimatum game.
Two players, one offers to split money in a certain way to responder.
Responders were scanned using FMRI’s.
Found that when the responder rejected unfair offers the svans showed heightened response in the amygdala.
Association between aggression and amygdala.
Does the amygdala work in isolation?
No- seems to work with the orbiti-frontal cortex, part of the limbic system.
What is the Orbito-frontal cortex thought to be involved in?
In self control, impulse regulation and inhibition of aggresive behaviour.
What does Coccaro state about activity in the OFC in patients who suffer from aggressive psychiatric disorders>
Activity is reduced.
What is a limitation of the limbic explanation? -Other brain structures
Limbic systems function with the OFC, which is not part of the limbic system.
Is involved in impulse regulation and inhibition of aggressive behaviour.
Eg. Coccaro
Neural regulation of aggression is more complex.
What is serotonin?
A neurotransmitter with inhibitory effects throughout the brain. Key role in aggressive behaviour.
How is serotonin implicated in aggression?
It has widespread inhibitory effects in the brain. Normal levels in the OFC are linked with reduced firing neurons, which is associated with greater self control.
What can decreased serotonin mean?
It disrupts the normal mechanism. Can reduce self-control and lead to increased impulsive behaviour including aggression.
What can Virkkunen’s findings tell us about the role of serotonin in aggression?
Compared levels of serotonin breakdown product in the cerebrospinal fluid of violent impulsive and non-violent impulsive offenders. The levels were significantly lower in the impulsive offenders.
How do serotonin treatments such as drugs support serotonin’s implication in aggression?
Berman et al gave ppts either a placebo or paroxetine.
They then took part in a lab based game in which electric shocks of varying intensity were given and received in response to provocation.
Paroxetine ppts consistently gave fewer and less intense shocks than the placebo group, only when ppts had a history of violence,
Shows the link between serotonin in function and aggression.
How do serotonin treatments such as drugs support serotonin’s implication in aggression?
Berman et al gave ppts either a placebo or paroxetine.
They then took part in a lab based game in which electric shocks of varying intensity were given and received in response to provocation.
Paroxetine ppts consistently gave fewer and less intense shocks than the placebo group, only when ppts had a history of violence,
Shows the link between serotonin in function and aggression.
What is testosterone?
A hormone that is produced mainly in the male testes, associated with aggressiveness.
How is testosterone implicated in aggression?
Male aggression is seen to be higher than female.
When aggression peaks in puberty males appear to be most aggressive.
Testosterone also has a role in regulating social behaviour via it’s influence on certain areas in the brain implicated in aggression.
What did Giammanco’s castration study find?
Removing the testes reduces aggression in the males of many species.
Giving injections of testosterone to the same animals restores aggressive behaviour.
What did Dolan’s study on prison populations find?
Positive correlation between testosterone levels and aggressive behaviour in a sample of 60 offenders in UK max security holdings.
These men mostly had personality disorders and histories of impulsively violent behaviour.
What is a limitation found for the link between testosterone and aggression found by Carre and Mehta?
Dual hormone hypothesis. High levels of testosterone lead to aggressive behaviour but only when levels of cortisol are low. When cortisol is high, testosterone’s influence on aggression is blocked. Cortisol plays a role in stress. Therefore the combined role may be a better explanation.
How is the MAOA gene implicated in aggression?
Low-activity is closely associated with aggressive behaviour.
What can a lack of MAOA mean?
An excess of neurotransmitters which cause people to respond excessively to stress. May lead to abnormal activity of the enzume, resulting in abnormal levels of the neurtransmitters.
