1. Neural explanations for offending behaviour
Do criminals have criminal brains?

2. Brain Structure The PFC and the Amygdala
The pre-frontal cortex and amygdala are associated with aggression and if these parts are damaged individuals become aggressive.
Raine PFC = Antisocial personalities Amygdala = Psychopathy

3. DEFICITS IN THE FRONTAL LOBE
Many studies show that antisocial and violent offenders have damage to the pre-frontal lobe.

4. Raine used a PET scanner to look at Brain activity
Using a PET Scanner

5. The red/orange area are the most active
PET Scan

6. Raine (1997) studied 41 violent offenders (NGRIs) and compared the activity in their prefrontal lobes to 41 non-criminals (including 6 schizophrenics) using PET scans. The NGRIs showed significantly less activity in prefrontal lobe than the other participants suggesting less control over impulsive behaviour. He also found reduced activity in the amygdala and hippocampus which are part of the limbic system responsible for emotional expression.

7. Raine (2009)
"The amygdala is the seat of emotion. Psychopaths lack emotion. They lack empathy, remorse, guilt,"
Raine Compared 27 psychopaths to 32 non-psychopaths.
He found that the Psychopaths had an 18% volume reduction in the amygdala, and thinning of the cortex

8. Raine also found an 11% reduction in grey matter of the Pre Frontal Cortex in people with Anti Social Personality Disorder compared to controls

9. Raine suggests that the prefrontal lobe develops relatively late, sometimes it is not full developed until early 20s. This may explain peak in antisocial behaviour by male teenagers!
There is a correlation between teenagers with anti social tendencies and either slow maturation of frontal lobe or damage to prefrontal lobe.

10. Additional Support comes from
Anderson et al (1999) carried out case studies of two individuals who had received damage to their frontal lobes before the age of 16 months. Both of the individuals showed increased aggression in childhood and adulthood. Anderson claims that the brain damage disrupts the normal development of social and moral behaviour. You can also use Charles Whitman and Phineas Gage

11. Other structural explanations
Neurons
What are neurons?
What different types are there?

12. Mirror neurons
You're walking through a park when out of nowhere, the man in front of you gets smacked by an errant Frisbee. Automatically, you recoil in sympathy.
Or you're watching a race, and you feel your own heart racing with excitement as the runners vie to cross the finish line first.
Or you see a woman sniff some unfamiliar food and wrinkle her nose in disgust. Suddenly, your own stomach turns at the thought of the meal.
Mirror neurons are a type of brain cell that fires when you do an action, and also when you simply watch someone else doing the same action. They help us understand and interpret the actions of others.

13. Mirror neurons
People with Anti Social Personality Disorder show sporadic empathy
Keysers et al (2011)
Found that when ASPD were asked to empathise, they did …which suggests
Their Mirror neurons became activated
Wheras for most people, empathy is always switched ‘on’

14. Chemical mechanisms and offender behaviour

15. Two neurotransmitters and a hormone
Neurotransmitters: Serotonin Dopamine
Hormone:
Testosterone

16. What is a neurotransmitter?
Neurotransmitters are chemicals that help transport the electrical impulse across the synaptic gap.
Different neurotransmitters are associated with different neurons and overall functions. Therefore it is possible to isolate some specific roles for specific neurotransmitters.

17. Essentially the argument is
Low levels of serotonin are associated with aggression
High levels of dopamine

18. The Role of Serotonin
It is thought that serotonin inhibits responses to emotional stimuli that have the potential to lead to aggressive behaviour.
Low levels of it are linked to increases in impulsive behaviour, aggression & even violent suicide.

19. Serotonin: Evidence Mann et al. (1990)
35 healthy ppts were given dexfenfluramine – known to lower serotonin.
They were then given a questionnaire to assess hostility & aggression.
They found that the drug increased aggression & hostility scores in males – not females.
Scerbo & Raine (1993) – meta-analysis supports low level of serotonin being associated with aggression

20. Serotonin: Evidence Bond (2005)
Conducted clinical studies with antidepressant drugs that increase serotonin.
He found that irritability and impulsive aggression were reduced.
What could be the possible advantages of finding a chemical explanation for aggressive or anti social criminal behaviour ?

21. Link less well established than serotonin, but still some evidence.
The Role of Dopamine
Lavine (1997) –showed that amphetamines (which increase dopamine) increases aggressive behaviour in rats
Link less well established than serotonin, but still some evidence.
Buitelaar (2003) –showed that anti-psychotics
(which reduce dopamine) reduced aggressive
behaviour in violent delinquents

22. What are Hormones?
Chemical substances that circulate in the blood and only affect target organs. They are produced in large quantities but disappear very quickly. Their effects are slow in comparison to the nervous system, but are very powerful.

23. The Role of Testosterone
Is a male sex hormone.
Thought to act on areas of brain which control aggression from young adulthood onwards.
Thought to be primary biochemical influence on aggression.

24. Essentially the argument is
that High levels of testosterone
..... are associated with aggression

25. In humans and other mammals, testosterone is secreted primarily by the testicles of males and, to a lesser extent, the ovaries of females. Small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid.

26. Neurochemical
Individuals who take large amounts of steroids can become extremely violent (known as "roid rage"). Steroids, usually taken to increase muscle growth, also increase testosterone levels. Horace Williams, a body builder, beat a man to death after taking two thousand times the recommended dosage of steroids.

27. Testosterone: Evidence
Dabbs et al. (1987):
Measured salivary testosterone in violent & non-violent criminals.
Highest testosterone in violent criminals and lowest in non-violent criminals.

28. Testosterone: Evidence
BUT!
Not all evidence is consistent.
Albert et al (1993) – suggest that not all studies find a correlation between testosterone and aggression.
Plus most correlational studies inc small samples of men in prisons & use either self-report measures of aggression or judgements based solely on severity of crime committed.

29. Evaluation issues Remember to think critically
about these explanations.
Come up with your own
Evaluation points.
Check out what the text book
And T2U pack suggest the
main issues are