Turning to Crime - Biology - Raine

Raine - Brain damage can cause changes in behaviour, including loss of self-control and increased aggression, depending on which region of the brain is affected.

Aim: Investigate pattern of brain activity in murderers and non-murderers using PET scanning measuring levels of lower glucose metabolism.

Method & Procedure: Experimental group;41 participants;charged with murder;pleaded not guilty "on reasons of insanity" IV = Murderer/Non-murderer DV = measures of brain activity and structure found using PET scans.

Results: Significant differences in brain metabolism of glucose found between murderers/non-murderers. Murderers had lower activity in following regions of the brain:

• Pre-frontal cortex = Lower glucose metabolism in some pre-frontal lobes of the brain
• Limbic system = different levels of activity in amygdala and hippocamous
• Corpus callosum = less activity here
• Example: Impulsive/aggressive behaviours - Assault- normal person maybe impulsive to assault someone whereas someone with brain dysfunction may assualt someone anyway
  

Conclusion: Whilst this explains why brain dysfunction can contribute to crime, no causal relationships.