structure of the brain - explanation for aggression Flashcards
what is aggression
range of behaviours that may result in physical or physiological harm to ones self or others
can be verbal or physical
what are the types of aggression?
person orientated
instrumental
reactive
sanctioned
what is person orientated aggression?
when the goal is to harm others
what is instrumental aggression?
obtain some kind of reward
what is reactive aggression?
in response to a hostile situation
what is sanctioned aggression?
permitted as overall outcomes is seen as justifiable
eg a war
what are the three areas of the brain associated with aggression?
amygdala
prefrontal cortex
midbrain
how can the midbrain explain aggression?
contains as area called the pariaqueductal grey matter (PAG) which links hypothalamus to the prefrontal cortex
it coordinates and integrates behaviour to perceived stressors
lesions in PAG in rats who increase aggression to males when just given birth
what does the PAG link?
the hypothalamus to the prefrontal cortex
what does the PAG do?
coordinates and integrates behaviour to perceived stressors
how has the role of the PAG been shown?
it has been found that when females rats have a lesion in their PAG after giving birth they show increased aggression towards unfamiliar males
how can the amygdala explain aggression?
it is the centre for emotion and motivation
integrates stimuli from senses which when combined give reactions to the environment including aggression
having a small amygdala in linked to aggression
how the structure of amygdala linked to aggression?
smaller one
what does the amydgdla integrate?
integrates stimuli from the senses that when combined give reactions to the environment
how is the prefrontal cortex linked to aggression?
it is influential in governing social interactions and behaviour
anger is though to arise when lack of control occurs at the prefrontal cortex
what does the prefrontal cortex govern?
social interactions and behaviour
how does anger arise from the prefrontal cortex?
when there is a lack of control here
where does offensice aggression occur?
at the medial hypothalamus
where does defensive aggression occur?
at the dorsal hypothalamus
where does predatory aggression occur?
at the lateral hypothalamus
what does the hypothalamus do?
it is linked to homeostasis through the regulation of hormones
linked to male aggression
how is the hypothalamus linked to makes aggression?
abnormal activity in testosterone in males
what did downer find?
monkeys had their optic nerve cut form and one amygdala removed
found if monkeys had a visual input to their amygdala they would react aggressively to humans but if it was cut they would remain placid
case studies adding support?
phineas gage
severe damage to his prefrontal cortex due to an injury
showed a changed in personality and increase in aggression
‘animal’
problems with case studies?
generalisability
individual differences
hw does raine link?
he found much lower activity in the prefrontal cortex in murderers
what did swantje find?
found that there was a correlation between to the size of the amygdala and self reported aggression
smaller amygdala linked to aggression
how can techniques used to study it be a strength?
pet etc
credible
reliable
research done on animals?
can’t do it on humans
generalisability
