Classic Evidence

• What type of experiment was Raine et al's study?

  Quasi-experiment.
• What was the independent variable in Raine et al's study?

  Murderers vs. non-murderers.
• What is a limitation of quasi-experiments like Raine et al's study?

  Lack of control over extraneous variables.
• What was the dependent variable in Raine et al's study?

  Differences in brain activity.
• What does a lack of control in Raine et al's study affect?

  Establishing cause and effect relationships.
• What does the unclear direction of effect in Raine et al's study imply?

  Crime may cause brain activity differences.
• What was the experimental design used in Raine et al's study?

  Matched pairs design.
• How did Raine match participants in his study?

  Based on age and sex.
• What is a strength of using a matched pairs design in Raine et al's study?

  It controls for participant variables.
• How many murderers were in Raine et al's experimental group?

  41 murderers.
• What was a limitation of Raine et al's sample?

  It was unrepresentative and biased.
• Why does Raine et al's sample lack population validity?

  It cannot be generalized to all offenders.
• What sampling technique did Raine use?

  Opportunity sampling.
• What is a strength of using PET scans in Raine et al's study?

  They provide objective and replicable results.
• What is a limitation of PET scans mentioned in Raine et al's study?

  Potential error in interpretation of findings.
• What tracer was used in the PET scans of Raine et al's study?

  Fluorodeoxyglucose (FDG).
• What was the purpose of the Continuous Performance Task in Raine et al's study?

  To activate target areas of the brain.
• Why is the standardization of the Continuous Performance Task a strength?

  It ensures consistent brain activity measurement.
• What was the time frame for the PET scan after the FDG injection?

  32 minutes.
• What did the findings reveal about the frontal lobe in NGRI participants?

  They had less activity than the control group.
• What does reduced activity in the frontal lobe indicate?

  Linked to impulse control and immaturity.
• What was observed in the parietal lobe of NGRI participants?

  Less activity in the left angular gyrus.
• What does reduced activity in the parietal lobe suggest?

  Linked to poor verbal skills.
• What was the activity level in the temporal lobe between NGRI and control groups?

  No difference in activity.
• What was found in the occipital lobe of NGRI participants?

  Higher activity than the control group.
• What did the metabolic activity show regarding asymmetries in NGRI participants?

  Reduced activity on the left hemisphere.
• What brain structures showed no differences in activity?

  No differences in structures associated with mental illness.
• What was observed in the cerebellum of NGRI participants?

  Increased activity compared to the control group.
• What was the activity level in the corpus callosum of NGRI participants?

  Less activity than the control group.
• What is the function of the frontal lobe?

  Linked to impulse control and immaturity
• How did the activity of the frontal lobe in NGRI compare to the control group?

  NGRI had less activity than the control group
• Which area of the brain is linked to poor verbal skills?

  Left angular gyrus in the parietal lobe
• What was observed in the parietal lobe activity of NGRI individuals?

  NGRI had less activity, especially in the left angular gyrus
• How did the temporal lobe activity of NGRI compare to the control group?

  No difference in activity
• What was the activity level of the occipital lobe in NGRI individuals?

  NGRI had higher activity than the control group
• What did metabolic activity show about brain asymmetries in NGRI individuals?

  Reduced activity on the left hemisphere
• Which brain structures showed abnormal asymmetries linked to violence?

  Hippocampus, amygdala, and thalamus
• What was the cerebellum activity level in NGRI individuals compared to the control group?

  NGRI had increased activity
• How did the corpus callosum activity of NGRI individuals compare to the control group?

  NGRI had less activity than the control group
• What was the relationship between observed brain differences and task performance on the CPT?

  No relationship; both groups performed similarly