Title: Raine et al (1997) Brain abnormalities in murderers
1Raine 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
2Raine 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
3Raine et al (1997) Brain abnormalities in
murderers
Mark Souter psychlotron.org.uk
PET scans showing hot spots for cognitive
activities
4Raine 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
5Raine et al (1997) Brain abnormalities in
murderers
PET scan of a subject whilst practicing a new
language skill
Mark Souter psychlotron.org.uk
6Raine 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
7Raine 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
8Raine 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
9Raine 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
10Mark Souter psychlotron.org.uk
11Raine 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
12Raine 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
13Raine 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
14Raine 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
15Raine 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
16Raine 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
17Raine 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
18Raine 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
19Raine 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