Classic Study - Raine et al 1997
brain abnormalities in murderers
aim:
Wanted to use brain scanning technology to identify impairments in people charged with
murder who had pleaded not guilty by reason of insanity (NGRI). The researchers hypothesised
that brain scans would show dysfunctions in areas linked in previous research to violence - the
prefrontal cortex, amygdala, hippocampus, thalamus and corpus callosum.
method:
The study looked at differences between 2 groups - 41 murderers and 41 non-murderers.
IV = murderer or non-murderer.
DV = glucose metabolism in specific brain areas.
Participants are not assigned to these conditions and therefore it is not a true experiment.
A matched pairs design was used.
Findings:
Cortical regions - murderers had
procedure:
significantly lower glucose metabolism than
Experimental group consisted of 39 men
controls in the lateral and medial
and 2 women charged with murder or
prefrontal areas, left angular gyrus, and
manslaughter in California.
left and right superior parietal areas.
They were free from all medication in the 2
Murderers showed higher metabolism than
weeks up to their brain scan - confirmed
controls in the occipital lobe - linked to
by urine tests.
violence.
The murderers were matched by sex, age
Murderers had lower glucose metabolism
and ethnicity with a control group of non-
than controls in the corpus callosum, left
murderers.
amygdala, and left medial temporal lobe.
They had a physical examination and a
pshyctriatric interview.
conclusions:
Each participant underwent a PET scan of
Findings showed that murderers pleading
their brain, injected with a radioactive
NGRI have different brain activity from
tracer to ‘light up’ brain metabolism.
people who are not violent offenders.
They completed continuous performance
Dysfunctions of a single brain area cannot
tasks for 32 minutes to encourage uptake
explain violent behaviour- the networks of
of radioactive glucose.
interacting brain areas are functionally
The scan took 10 slices through the brain
impaired.
at 10mm intervals.
The impairments create violence only in
expressed behaviour.
brain abnormalities in murderers
aim:
Wanted to use brain scanning technology to identify impairments in people charged with
murder who had pleaded not guilty by reason of insanity (NGRI). The researchers hypothesised
that brain scans would show dysfunctions in areas linked in previous research to violence - the
prefrontal cortex, amygdala, hippocampus, thalamus and corpus callosum.
method:
The study looked at differences between 2 groups - 41 murderers and 41 non-murderers.
IV = murderer or non-murderer.
DV = glucose metabolism in specific brain areas.
Participants are not assigned to these conditions and therefore it is not a true experiment.
A matched pairs design was used.
Findings:
Cortical regions - murderers had
procedure:
significantly lower glucose metabolism than
Experimental group consisted of 39 men
controls in the lateral and medial
and 2 women charged with murder or
prefrontal areas, left angular gyrus, and
manslaughter in California.
left and right superior parietal areas.
They were free from all medication in the 2
Murderers showed higher metabolism than
weeks up to their brain scan - confirmed
controls in the occipital lobe - linked to
by urine tests.
violence.
The murderers were matched by sex, age
Murderers had lower glucose metabolism
and ethnicity with a control group of non-
than controls in the corpus callosum, left
murderers.
amygdala, and left medial temporal lobe.
They had a physical examination and a
pshyctriatric interview.
conclusions:
Each participant underwent a PET scan of
Findings showed that murderers pleading
their brain, injected with a radioactive
NGRI have different brain activity from
tracer to ‘light up’ brain metabolism.
people who are not violent offenders.
They completed continuous performance
Dysfunctions of a single brain area cannot
tasks for 32 minutes to encourage uptake
explain violent behaviour- the networks of
of radioactive glucose.
interacting brain areas are functionally
The scan took 10 slices through the brain
impaired.
at 10mm intervals.
The impairments create violence only in
expressed behaviour.
