L4 - Brain Functioning in Antisocial and Violent Behaviours

Question 1

Who was Randy Craft?

Answer 1

The freeway killer, raped, tortured, mutilated and murdered 67 young males. Met future victims at bars, buying them drinks, took 12 years to catch him

Question 2

Who was Antonio Bustamante?

Answer 2

Mexican/American drug addict, arrested 29 times for a variety of crimes; theft, breaking and entering, fighting etc. One-time murderer.

Question 3

What did a PET scan show about brain differences between Antonio Bustamante and controls?

Answer 3

Much less glucose metabolism in the OFC of Antonio Bustamante

Question 4

What did a PET scan show about brain differences between Randy Craft and controls? (And the comparison with the difference between Bustamante and controls)

Answer 4

Randy Craft’s PET scan was more similar to controls than the similarity of Bustamante’s scan with controls.

Question 5

What did Raine et al., (1994) show with PET scans on murderers?

Answer 5

Murderers on death row did a continuous performance task - engages PFC.

Murderers had reduced glucose metabolism in the medial and lateral PFC.

Question 6

What did Raine et al., (1997) find about cortical and sub-cortical differences between murderers and controls?

Answer 6

Murderers tested on a continuous performance task, but cortical and subcortical metabolism was measured.

Murderers had reduced glucose metabolism in PFC, superior parietal cortex, corpus callosum, and subcortical: reduced metabolism in left hemisphere of thalamus, and hippocampus.

Question 7

Using PET scans, what did Raine et al., (1998) find about differences in PFC activity between reactive and proactive murderers?

Answer 7

Reactive showed lowest level of lateral and medial prefrontal metabolism, compared to controls.

Proactive murderers did not differ from controls in PFC activity, but did differ from reactive murderers - showing they are more similar to the controls than to reactive murderers.

Question 8

Using PET scans, what did Raine et al., (1998) find about differences in sub-cortical activity between reactive and proactive murderers?

Answer 8

No differences in glucose metabolism on left hemisphere, but difference on right:

Both types of murderers showed higher levels of subcortical metabolism than controls.

Therefore, it could be that sub-cortical abnormalities induce a certain propensity to murder, but PFC deficiencies which determine the type of murders.

Question 9

What is intermittent explosive disorder?

Answer 9

Characterised by impulsive acts of aggression and rage that are completely disproportionate to any altercation. Outbursts typically occur several times per week.

Question 10

What are the typical characteristics of individuals with intermittent explosive disorder?

Answer 10

High level of hostility, trait anger.

Question 11

What is the prevalence of IED in the US?

Answer 11

5% of the population

Question 12

Using fMRI, what did Coccaro et al., (2007) find about brain activity in those with IED?

Answer 12

Looked at brain responses to emotionally salient faces and found no group differences in correctly identifying the emotions displayed.

Patients showed heightened amygdala response, and had lower OFC responses in comparison with controls.

Found a positive correlation between amygdala response to angry faces and the levels of reported lifetime aggression.

Patients failed to demonstrate amygdala-OFC coupling as seen in controls, in response to angry faces - this dysfunctional relationship was suggested as the mechanism for which the IED manifests.

Question 13

What did Lee et al., (2008) find about spouse abusers and fMRI activity?

Answer 13

Typically, explanations for spouse abuse are social. Colour/cognitive and emotional stroop

Abusers showed higher levels of reactive aggression compared to controls.

Abusers took longer to respond to emotional words on stroop, showing emotional words grabbed their attention more than neutral words.

Abusers showed reduced activity in medial frontal gyrus, anterior cingulate cortex |(frontal areas) but increased response in amygdala and parahippocampal gyrus, as well as in the midcingulate and posterior insular (subcortical areas)

–> Reduced engagement of PFC, but heightened subcortical response.

Question 14

What did Lee et al., (2002) find about lying?

Answer 14

Lying recruits a number of regions in the medial and lateral PFC.

Question 15

Describe Green et al’s (2001) personal moral dilemma?

Answer 15

Pushing one fat guy onto a train track, to stop the train and save 5 people tied down further along the track

Question 16

Describe Green et al’s (2001) impersonal moral dilemma?

Answer 16

Switching the track to divert the train onto a path which kills one individual tied to the track, instead of killing 5 tied to the original path.

Question 17

What did Green et al., (2001) find about the regions of activity when facing moral dilemmas (i.e. saving 5 or 1 person tied to train tack)

Answer 17

When facing personal moral dilammas, there is a heightened response in emotional regions ushc as the medial frontal gyrus, the posterior cingulate and the angular gyrus (core for social-cognitive processes, ToM, understanding intentions and emotions in others)

Question 18

What did Green et al., (2001) find about the regions of activity when facing immoral dilemmas (i.e. taxi or train to new street?)

Answer 18

When facing immoral dilemmas, regions associated with decision making, working memory, etc are activated.

Question 19

What did Green et al., (2001) find about the percentage of participants that would not be willing to push the person onto the tracks, for the personal moral dilemma?

Answer 19

85% of individuals would not be able to push the person to sacrifice 5 others.

Question 20

What did Green et al., (2001) find about the percentage of those with vmPFC damage that would agree to push the person in the personal moral dilemma?

Answer 20

45% of people with vmPFC damage would be able to push the person to save 5 others.

Question 21

What did Koenigs et al., (2007) find about damage to the PFC and moral personal vs impersonal judgements?

Answer 21

No group differences between moral vs non moral dilemmas.

50% of vmPFC patients say they would kill the child to save everyone - far higher than controls.

As the complexity and severity of the judgements increase, the vmPFC patients endorse the yes much more than the controls.

Question 22

What is the vmPFC responsible for?

Answer 22

Important for galvanic skin conductance response when feeling anxious - seems to be functional linkage with the amygdala.

Question 23

What did Koenigs & Newman (2012) find when using moral dilemmas in psychopathic prisoners?

Answer 23

Compared psychopathic prisoners with non-psychopathic prisoners

Found a group difference only for the non-personal scenarios.

Split psychopaths according to primary and secondary psychopathy

–> then they found that primary psychopaths said yes more to personal moral dilemmas than secondary psychopaths and non-psychopaths.

Question 24

What is thought to be the difference between primary and secondary psychopathy?

Answer 24

Primary psychopathy is thought to be caused more by genetic factors, and individuals tend to be lower in anxiety.

Secondary is thought to be due to environmental factors, and individuals tend to be much more anxious.

Question 25

What did Glenn (2009) show about the relationship between psychopathy ratings and brain responses? Which facet of psychopathy is important, and how?

Answer 25

Higher on psychopathy, less response in a number of regions for personal moral judgements - less response in amygdala. It is the interpersonal-affective facet which correlates with decreased activity in the posterior cingulate cortex, medial PFC, angular gyrus and the amygdala.

Question 26

What did Contreras-Rodriguez et al., (2014) find about differences in neural processing of emotional faces between psychopaths and healthy controls?

Answer 26

Psychopathic prisoners vs healthy controls. Results are based on the difference in processing between emotional faces and an identical arrangement of shapes. No difference in reaction time or accuracy. Psychopaths had relatively equal activation between the emotional faces and the control shapes, whereas the control subjects had more activation for the faces. Psychopaths had greater activation than controls in occipital areas/visual processing, and cold cognitive processes than controls when processing emotional faces. Shows psychopaths recruit more cold cognitive processes than controls in order to perform similarly, suggesting they are deficient or reluctant to use the areas that healthy controls do.

Question 27

What did Seara-Cardoso and Viding (2015) find about

Answer 27

Psychopaths showed less connectivity between the amygdala and the visual cortex. Higher they were on the interpersonal-affective factor of psychopathy, the greater the activation of the PFC in response to emotional faces.

Question 28

What did Poeppl et al., (2019) find in their meta-analysis of functional brain activity in psychopaths?

Answer 28

Psychopathy is associated with reduced activity in the left lateral PFC, right lateral PFC, dorsolateral PFC and the amygdala. Reduction in emotional responses, e.g. amygdala, language areas and cognition. But increased activity in areas of cognitive, cold processes.

Question 29

What did Passamonti et al., (2010) find about neural abnormalities in early onset and adolescent onset conduct disorder?

Answer 29

Implicit emotion processing. Difference in processing between angry and neutral faces: Both CD types show decreased amygdala and vmPFC response to angry faces (which disagrees with Moffitt's theory that neural causes of CD are only expected for life-course persistent/early onset) Only early onset showed reduced amygdala onset bilaterally AND vmPFC activity in response to sad faces.

Question 30

What did Fairchild et al., (2014) show about females with CD?

Answer 30

Females with CD do not show differences based on emotion, they show reduced OFC activity in response to angry, sad and neutral faces. Increased insular activity across all emotions too.

Question 31

What did Adolphs et al., (2005) find about

Answer 31

The amygdala is essential for drawing attention to the eyes, in order to process fearful facial expressions. Attention is on the mouth for happy faces - performance did not differ between patient SM and controls for facial expressions other than fear If you ask patient SM to look at the eyes, performance for recognising fearful faces is the same as controls.

Question 32

What did Dadds et al., (2010) find about the relation between CU traits and processing of emotional faces?

Answer 32

Those with high CU traits focus more on the mouth, and not so much on the eyes. Those with low CU traits spent time focusing on the eyes that was similar to controls. Suggests amygdala deficiencies/abnormalities could underlie mechanisms for conduct disorder in those with high CU traits.

Question 33

What did Jones et al., (2009) show about amygdala activity in response to fearful faces in boys with conduct problems and callous-unemotional traits?

Answer 33

Young people with conduct disorder and high levels of CU traits show reduced amygdala response to fearful facial expressions compared to controls.

Question 34

What did Lozier et al., (2014) find about the relationship between CU traits, amygdala activity and proactive aggression in children with conduct problems?

Answer 34

In response to fearful facial expressions, When CU traits are controlled for, the higher you are on conduct problems the higher the amygdala response to fearful facial expressions. When conduct problems are controlled for, the higher on CU traits, the lower the amygdala response to fearful faces. Relationship between CU traits and proactive aggression is mediated by the amygdala activity in response to fearful faces.

Question 35

What did Viding et al., (2012) find about subliminal facial processing for fearful and calm facial expressions between youths with conduct problems with high and low CU traits?

Answer 35

Showed fearful and calm/neutral facial expressions for 17 milliseconds. In fear conditions, they were then shown a neutral face. In calm conditions, they were also shown a neutral face. Low level of CU showed heightened amygdala response, and a hypo-response, decreased activity in those with high CU traits and conduct problems. This pattern could underpin proactive, instrumental aggression for those with high CU traits, and could be the core of heightened, threat-based, reactive aggression seen in youth with CP and low CU traits.

Question 36

What did Viding et al., (2012) show about the relationship between amygdala response and CU traits in youths with conduct problems?

Answer 36

Among youth with CP, there was a linear negative relationship between amygdala response and level of CU traits. The higher on CU traits, the lower the amygdala response to facial expressions.