Neural and Hormonal Mechanisms Flashcards
Name 3 parts of the limbic system.
Hypothalamus, amygdala and hippocampus.
What does a more reactive amygdala indicate?
A person is likely to be more aggressive.
What behaviours did Raine say asymmetry of the hippocampus leads to?
Why does this happen?
Inappropriate verbal and physical responses.
The amygdala and hippocampus cannot work effectively.
What relationship did Pardini find between amygdala volume and severe aggression?
Reduced amygdala volume can predict development of severe aggression.
Explain why people with normal levels of serotonin in the orbito frontal cortex are associated with greater levels of self control.
Firing of neurones is reduced.
What does low serotonin do to behaviour?
Causes us to have less self control and become more impulsive.
Explain what changes to aggression levels occurred in people changing gender. (Van Goozen)
MtF - became less aggressive and sexual as testosterone levels are supressed
FtM - became more aggressive due to testosterone injections
What is testosterone?
An androgen responsible for development of male sex characteristics.
At what age are men most aggressive and why?
During their 20s when testosterone levels are highest.
Describe Giammancos animal castration research.
Removed the testes of animals and found that aggression decreased. When animals were injected with testosterone, aggression increased.
What does progesterone do?
Regulates aggression in females.
Women rated on a self report scale how aggressive they felt. What did higher ratings of aggression coincide with?
Low levels of progesterone.
Explain the strength of the neural explanation having support from drug studies.
How does increased serotonin affect aggression?
Name the drug that Berman gave PPTs.
Describe the game PPTs played involving electric shocks.
How did the shocks given by the group that took drugs compare to the control?
What relationship does this suggest about serotonin function and aggression?
Drugs that increase serotonin levels have also been found to reduce aggressive behaviour. Berman gave PPTs either a placebo or a dose of a drug called paroxetine. The PPTs then took part in a lab-based game that involved giving and receiving electric shocks in response to provocation. The paroxetine group consistently gave fewer and less intense shocks than the placebo group. Therefore, this research demonstrates a causal link between serotonin function and aggression.
Explain the limitation of non limbic brain structures being involved in aggression.
Name a part of the brain that the limbic system works with in aggression.
What does this part of the brain do?
What happens to activity in this part of the brain when a person suffers from disorders featuring aggression?
What does this tell us about limbic system explanation?
Limbic structures such as the amygdala function together with the orbitofrontal cortex, which is not part of the limbic system. The orbitofrontal cortex is involved in impulse regulation and inhibition of aggressive behaviour. According to Coccaro, OFC activity is reduced in those psychiatric disorders that feature aggression. This reduced activity disrupts the OFCs impulse control, causing aggressive behaviour. This shows that the neural regulation of aggression is more complex than theories just studying the amygdala.
Explain the strength of there being support from non human animal research.
What does Giammanco’s study tell us about the role of testosterone?
In monkey mating season, why is testosterone high?
In rats, when they are castrated, what happens to their behaviour?
On the other hand, what are the issues with using animal studies?
Giammancos review of studies confirms the role of testosterone. For example, in male monkeys, there is an increase in both testosterone levels and aggressive behaviour during the mating season. In rats, castration of males reduces testosterone and mouse killing behaviour. Injecting female rats with testosterone increases mouse killing, demonstrating the importance of testosterone in aggression. Hormonal mechanisms involved in aggression in humans and other mammals has also proven to be similar, however, human aggression is thought to be much more complex than in animals, therefore, we should be less reliant on generalising findings from animal studies to humans.
