aggression - neuronal and hormonal mechanisms Flashcards
what are the two types of aggression?
impulsive aggression - unplanned and characterised by strong emotions
instrumental aggression - carefully planned with the intention of achieving a goal.
what is the role of amygdala?
in humans and animals and how they respond to their threats and challenges and the stimulation of the amygdala can increase/ decrease aggression response.
what is the role of the hippocampus?
involved in the formation of long-term memories and allows comparison with the current threat to similar past experiences.
damaged hippocampus
it prevents the nervous system from putting things into a relevant and meaningful context and it can cause the amygdala to respond inappropriately.
research support - limbic system
gospic et al 2011 - participants with mild aggression, fmri scans, a benzodiazepine drug lead to lower levels in the amygdala and aggression reduced.
what is the orbifrontal cortex and serotonin?
serotonin is linked with communication of impulse between neurons, there is an inhibitory effect on the neural firing in the amygdala, it slows down neuronal activity.
normal levels of serotonin
linked with reduced firing of neurons = self-control
decreased serotonin
no self-control = aggression (densen et al 2012)
testosterone
male characteristic is linked to aggression in males, produced in spurts, levels can rise suddenly and have an effect within minute.
giammanco et al 2005
castration studies on animals showed that removing the testes reduced aggression and injecting it back in caused aggression.
dolan et al 2001
positive correlation between high levels of testosterone and prisoners.
progesterone
low progesterone = aggression of women. levels of progesterone vary during ovulation cycle and the lowest after menstruation/
zimokiewicz 2012
negative correlation between progesterone levels and self-reported aggression.
