Neural

• Prefrontal cortex / Limbic system - Raine et al

  investigated the link between brain abnormalities and criminality

  Imaging stud on 411 murderers and 41 controls matched on age and sex - all murderers had pled not guilty on the base of insanity

  found differences in activity (reduced glucose metabolism) in the PFC and asymmetrical activity in the limbic systems (eg, amygdala)

  This supports there is a link between neural dysfunction and violent crime
• Prefrontal cortex / Limbic system - Raine

  Conducted many studies of the APD brain, reporting that there are several dozen brain-imaging studies demonstrating that individuals with antisocial personalities have reduced activity in the prefrontal cortex, the part of the brain that regulates emotional behaviour

  Alongside this, Raine and his colleagues (2000) found an 11% reduction in the volume of grey matter in the prefrontal cortex of people with APD compared to controls
• Mirror Neurons 


  Recent research suggests that criminals with APD can experience empathy but they do so more sporadically than the rest of us

  Kesters et al (2011) found that only when criminals were asked to empathise (with a person depicted on film experiencing pain) their empathy reaction (controlled by mirror neurons in the brain) activated

  This suggests APD individuals are not totally without empathy, but may have a neural switch that can be turned on and off, unlike the normal brain which has empathy switch permanently on
• Neurotransmitters


  Serotonin - normally involved in inhibitions of the prefrontal cortex, low levels of serotonin may increase impulsive and aggressive behaviours

  Dopamine - high levels can also contribute to impulsive and aggressive behaviours - involved in pleasure and addiction

  Noradrenaline - Extreme levels (high or low) associated with aggression and criminality.

  • High links to fight or flight behaviour
  • Low links to impaired ability to perceived threats