Topic 1: What Makes a Criminal? Key Study Flashcards
What was the aim of the study on brain abnormalities in murderers?
To compare brain activity in murderers versus non-murderers to see if differences exist in areas involved in violent behavior.
What method was used to assess brain activity in this study?
Positron Emission Tomography (PET) scanning during a Continuous Performance Task (CPT).
What does the Continuous Performance Task (CPT) involve in this research?
Participants watch stimuli appear one after another and press a button each time a specific stimulus appears; they practice beforehand, and the task lasts 32 minutes.
How were participants selected and matched for the study?
Participants were matched for age and sex, and none had taken medication in the two weeks before testing.
What comprised the sample groups in the study?
- Environmental Group: 39 men and 2 women (murderers, manslaughterers, or those pleading not guilty by reason of insanity).
- Control Group: 6 non-murderers.
How was the PET scan procedure carried out after the CPT?
Participants were injected with a fluorodeoxyglucose tracer, and PET images were taken in 10 horizontal slices of the brain (each slice 10mm thick).
What are the two techniques used to identify brain regions in this study, and what do they assess?
- Cortical Peel: Analyzes the lateral (sides and surface) areas of the brain.
- Box Technique: Analyzes the medial (inside) regions of the brain.
What abnormal brain activity was observed in murderers compared to controls?
Murderers showed:
- Reduced activity in lateral, medial, and parietal prefrontal cortical areas, and in the corpus callosum.
- Increased activation on the right side of the limbic system and amygdala.
- Reduced activation on the right in the temporal lobe, hippocampus, and thalamus.
Which brain regions with abnormal activity are linked to aggressive behavior?
The amygdala, hippocampus, and thalamus.
What abnormal brain function is associated with a lack of fear?
Abnormal activity in the amygdala is linked to a lack of fear.
Which brain area’s abnormality is related to impulsiveness?
Abnormalities in the prefrontal cortex are associated with impulsiveness.
How might abnormal activity in the amygdala, hippocampus, and prefrontal cortex affect emotional regulation?
It can cause problems with controlling and expressing emotions, which may lead to increased risk of extreme violence, difficulties in learning conditioned emotional responses, and an inability to learn from past experiences.
What are some broader consequences of these abnormal brain activities on behavior and life outcomes?
They can result in an increased risk of extreme violence, issues with emotional learning and regulation, and may contribute to problems like higher rates of unemployment due to impaired learning and social functioning.
What is the overall conclusion drawn from this study?
The study concludes that abnormal brain activity in specific regions increases the risk of committing serious crimes, suggesting a neurobiological basis for violent behavior.
