Raine et al (1997) Brain abnormalities in murderers

1
Raine et al (1997) Brain abnormalities in
murderers

• Brain abnormalities in murderers indicated by
  positron emission tomography
• Biological Psychiatry 42 495-508

Mark Souter psychlotron.org.uk
2
Raine et al (1997) Brain abnormalities in
murderers

• Introduction
• is there a biological basis for criminality?
• PET scans
• radioactive labels on
• blood/blood sugars
• dopamine (neuro-transmitter)
• ? gamma ray signals
• 7-8M ps
• also MRI and fMRI

Mark Souter psychlotron.org.uk
3
Raine et al (1997) Brain abnormalities in
murderers
Mark Souter psychlotron.org.uk
PET scans showing hot spots for cognitive
activities
4
Raine et al (1997) Brain abnormalities in
murderers

• introduction problems
• colourisation v complex ? errors
• 'hot spots' same for 'on 'off' brain actions
• practiced brain activity declines in that area
• ?'hottest spots' only for newest tasks?
• "it seems we should not let the quality of
  evidence get in the way of a good story" Banyard
  and Grayson 2000

Mark Souter psychlotron.org.uk
5
Raine et al (1997) Brain abnormalities in
murderers
PET scan of a subject whilst practicing a new
language skill
Mark Souter psychlotron.org.uk
6
Raine et al (1997) Brain abnormalities in
murderers

• the study subjects
• 41 people 39M 2F
• charged with murder
• pleading not guilty by reason of insanity (NGRI)
• all referred for PET for legal reasons
• average age 34.3

Mark Souter psychlotron.org.uk
7
Raine et al (1997) Brain abnormalities in
murderers

• the study subjects medical histories
• schizophrenia 6
• head injury/organic brain damage 23
• drug abuse 3
• affective disorder 2
• epilepsy 2
• hyperactivity or learning disorder 3
• personality disorder 2

Mark Souter psychlotron.org.uk
8
Raine et al (1997) Brain abnormalities in
murderers

• the study controls
• 1 for each subject
• matched for age / sex
• schizophrenics with non-murderer schizophrenics
• all controls screened for mental/physical health

Mark Souter psychlotron.org.uk
9
Raine et al (1997) Brain abnormalities in
murderers

• the study the PET process
• injection with glucose tracer
• 32 mins on target recognition task
• NRGI/controls compared re 14 LR brain areas
• 6 cortical
• inc prefrontal parietal temporal occipital
• 8 sub cortical
• inc corpus callosum amygdala hippocampus

Mark Souter psychlotron.org.uk
10
Mark Souter psychlotron.org.uk
11
Raine et al (1997) Brain abnormalities in
murderers

• the study ANOVA
• statistical comparison
• ANalysis Of VAriance
• compares a range of factors

Mark Souter psychlotron.org.uk
12
Raine et al (1997) Brain abnormalities in
murderers

• results cortical areas
• differences in activity in lobes of cerebral
  cortex cf controls
• parietal pre-fontal less activity ?
• occipital more activity ?
• temporal same ?

Mark Souter psychlotron.org.uk
13
Raine et al (1997) Brain abnormalities in
murderers

• results sub cortical areas
• less activity in corpus callosum cf controls
• a sub-cortical area ?
• cf Sperry

Mark Souter psychlotron.org.uk
14
Raine et al (1997) Brain abnormalities in
murderers

• results sub cortical areas
• imbalance between hemispheres cf controls in
• amygdala hippocampus less activity L / more R
• thalamus - more activity R / same L
• handedness made no difference
• ethnicity made no difference
• head injury patients corpus callosum only
  difference

Mark Souter psychlotron.org.uk
15
Raine et al (1997) Brain abnormalities in
murderers

• discussion authors (1)
• supports previous findings
• amygdala (part of limbic system) differences
  (linked to emotions lack of fear)
• corpus callosum differences linked to lack of
  long term perspective?
• cautious about implications

Mark Souter psychlotron.org.uk
16
Raine et al (1997) Brain abnormalities in
murderers

• discussion authors (2)
• results
• do not show violence is only biological in origin
  
• do not show NGRIs not responsible for their own
  actions
• do no say anything about causes of differences
• cannot be generalised from NGRIs to other violent
  offenders
• cannot be generalised to other types of crime

Mark Souter psychlotron.org.uk
17
Raine et al (1997) Brain abnormalities in
murderers

• discussion other issues
• imaging methods still being developed
• pre-scan task no bearing on violent behaviour
• NGRIs not necessarily charged with violent act
• cause ? effect of brain differences unclear

Mark Souter psychlotron.org.uk
18
Raine et al (1997) Brain abnormalities in
murderers

• discussion practical applications
• diagnosis of criminality?
• no clear evidence to support this
• treatment of criminality
• no clear evidence to support this

Mark Souter psychlotron.org.uk
19
Raine et al (1997) Brain abnormalities in
murderers

• discussion summary
• data unclear
• differences small
• cause-effect unknown
• meaning of differences unknown

Mark Souter psychlotron.org.uk