aggression: brain structure Flashcards
what is the role of the pre-frontal cortex
- executive decision making
- problem solving
- personality
- planning
how does Raine support the idea of pre frontal cortex causing aggression
- found lower activity in both hemispheres of 41 murderers
- concluded that the abnormality causes impulsivity and a lack of self-control
- inability to modify behaviour which can facilitate aggressive acts
strength of PFC
PG
a strength is the supporting evidence from Phineas Gage, who showed that damage to this area of the brain with an iron rod through the head changed his personality and he became imoulsive and inappropriate and often aggressive.
role of the amygdala
- perception of emotions such as fear and anger
- controlling aggresssion
- helps to store memories of events and the emotions of them
how does raine relate to the amygdala
Raine found reduced activity on the left side- 0.97 vs 0.94 between non murderers and murderers, which leads to reduced autonomic arousal in offenders, resulting in a lack of fear of consequences of being aggressive.
Also found increased activity in the right hand side- 0.88 vs 0.83 which suggests that aggressive individuals have a heightened emotional response to normal things, so may perceive non-threatening stimuli as a threat, leading to aggressive acts in defense of themselves.
how is the PFC linked to the amygdala
- the PFC inhibits the amygdala
- when damaged this will lead to an uninhibited amygdala leading to an increase in aggression
role of the hypothalamus
- the production of hormones
- regulates sleep
- involved in the expression of emotions
- if damaged, it could misread situations and release unnecessary hormones which cause aggression.
evidence for the hypothalamus
- Alpers (1937)
- well liked middle aged man who showed uncharacteristic outburts of aggression
- later found to have had a tumour in his hypothalamus
copliment of research (PEE)
raine’s research has high levels of inter-rater reliabilty. he used a PET scan to measure brain activity with a CPT of spotting targets for 32 minutes. Multiple researchers can therefore look at the objective images which the pet scans produced, with ten slices at 10mm intervals, and so this increases objectivity and inter rater reliability.
criticism of research (PEE)
A weakness of a case study is that it is difficult to generalise the results. For example, a case study of an individual person might not be representative of the brain structure of another because experiences are so individual that another person may not react in the same way. This is a problem as it’s difficult to generalise to the rest of the population as each case has unique characteristics therefore not representative.
weakness of research (C+E)
Research on brain strcture has low validity. there is no empirical evidence of how the person was before they experienced brain damage. therefore we cannot establish cause and effect of brain damage causing the change in behaviour as it may be due to other factors such as stress from the environment.
application (PEE)
raine’s research highlighted that people with damage to areas of their brain such as their prefrontal cortex can lead to impulsive behaviour. therefore we can identify those who may be more liekly to commit crimes and implement treatments such as amygdalotomies, reducing crime rates.
criticism of the theory
a weakness of this theory is that it is deterministic. it suggests that aggression is due to abnormalities in certain brain areas. therefore, it is ignoring the idea of free will and certain social situations acting as a trigger, saying that we are not in conreol of our own behaviour. this is thus deterministic as humans are more complex and this does not agree with societal ideas of responisibility.
