biological - amygdala

• What did Raine find?

  Abnormalities in the functioning of the limbic system are implicated in aggression
• what emotion is the amyglada involved in?

  aggression
• How many amygladas do we have?

  two
• What is IED (intermittent explosive disorder)


  IED is repeated, sudden episodes of impulsive, aggressive, violent behaviour or angry verbal outbursts that are out of proportion e.g. road rage. IED can cause stress and negatively impact things and its a chronic disorder, to treat this their are medications or psychotherapy.
• What did Coccaro et al (2007) find?


  he found that aggressive individuals with IED showed decreased OFC and increased amyglada activity when viewing angry faces compared to healthy subjects
• what did Matthies et al 2012 do and find?


  - investigated the relationship between amyglada size and aggression

  
  

  - brain scans were obtained from 20 healthy volunteers

  
  

  - found all volunteers scored in the normal range of lifetime aggression however those volunteers with higher aggression scores displayed 16-18% reduction of amyglada volumes.

  
  

  - negative correlation between amyglada size and aggression but volume might be a marker for levels of agression
• how does the functioning of the amyglada actually lead to the criminal behaviour?


  - amygdala dysfunction might lead to problems with processing fear.

  
  

  - geo et al, as children we learn to inhibit our aggressive and antisocial behaviours through fear conditioning - aggressive behaviour leads to punishment or negative outcomes

  
  

  - a dysfunction of the amygdala means the child cannot identify the social cues that indicate threat e.g. angry faces, therefore does not link punishment to aggressive behaviour.
• What did Gao et al find?


  - longtitudinal study where 1795 ppts were tested for fear conditioning at age three (sweating response to painful noise)

  
  

  - 20 years later the researchers found out which ppts had been involved in criminal behaviour

  
  

  - those who committed crimes by age 23 showed no fear conditioing at age 3, suggesting a causal relationship between amygdala dysfunction and criminal behaviour.
• Evaluation: Cause and effect

  - an issue with this theory is cause and effect, is it the defects in the amygdala function occur first and this causes criminal behaviour or is it criminal behaviour that causes changes to the amygdala.
• evaluation - alternative theories/diathesis stress

  - amygdala is an incomplete theory, it doesn't account for all criminal behaviour

  
  

  - can be caused due to upbringing/environment/genes ultimating the cause

  
  

  - not all criminals have a dysfunctional amygdala and not all people with an amygdala dysfunction show criminal or violent behaviour
• evaluation - Gospic et al research


  - used the ultimatum game, a lab based method of measuring aggressive behaviour using FMRI scans

  
  

  - involved two players, prosper/responder and a sum of money

  
  

  - the proposer offers to split the money in a fair/unfair way (unfair is seen as threatening), if responder accepts money, its split accordingly, but if they refuse they both get nothing - which is considered aggressive behaviour.

  
  

  - when the responder rejected unfair offered the amygdala was heightened and quicker