L6 - Neuropsychological and Structural Neuroimaging Correlates of Antisocial and Violent Behaviour Flashcards
Remember to read your lecture summaries - exam questions are very broad.
Who was the individual who sustained an injury with a pole in his head?
Phineas Gage - pole through his ventromedial PFC. Huge changes in behaviour.
Who was Michael, the 40-year-old schoolteacher (Glenn and Raine, 2014)?
Normal guy with a wife and stepdaughter, no history of crime or ASB. Developed a tumour which pressurised the vmPFC, resulting in ASB and inappropriate behaviour, soliciting sexual favours from prison staff, child molestation, bringing pornography into school etc.
Each time the tumour was treated for, the behaviour returned to normal.
What are the symptoms of ASPD?
Impulsivity Consistent irresponsibility Repeated criminal acts Repeated fights or assaults Recklessness Deceitfulness and lack of remorse Poor decision making - excessive risk taking
What do lesions to the vmPFC lead to?
Changes in:
- behaviour
- affect
- personality
Which look similar in presentation to ASPD or psychopathy.
Leads to theories that individuals with ASPD/psychopathy may have abnormalities within the PFC
What did Raine et al., (2000) find about white and gray matter differences between those with ASPD and controls?
Those with ASPD had 11% gray matter reduction in PFC compared to controls, and almost 14% reduction compared to substance dependent group.
What did Yang and Raine (2009) show about PFC differences in antisocial individuals?
Differences in 3 key subdivisions of the PFC in antisocial, violent or psychotic individuals compared to controls.
What did Aoki et al’s (2014) meta-analysis find about neural differences in those showing antisocial behaviour?
Antisocial individuals had reductions in gray matter in the superior frontal gyrus, insular (decision making and empathy) and part of the basal ganglia.
Increased gray matter in a number of regions.
What is affective decision making?
When you have to evaluate multiple different responses with differing probabilities of reward and punishment, followed by the selection of the optimal response.
What are the two types of affective decision making?
Under ambiguity - outcome probabilities are unknown
Under risk - outcome probabilities are known
What is the Iowa gambling task?
4 decks of cards, ABCD. 2 decks are good, leading to high levels of reward, and a 50% chance of punishment (i.e. $50 guaranteed reward, and 50% chance of a $50 deduction in addition). 2 decks are bad, leading to high levels of reward ($100), but 50% chance of a greater punishment too ($250).
PPS have 100 trials, each of which a card is drawn from a deck of their choice. They must work out themselves which decks are the most profitable in order to end with the highest amount possible.
What did Bechara et al., (1994) show about the performance on the Iowa gambling task by men with vmPFC lesions?
Controls would begin to shift their card selection from the bad decks to the good decks, once punishment ($-1,250) was introduced.
Patients with vmPFC lesions however, continued in their selection of cards from bad decks.
Only 50% of patients could conceptualise that two of the decks were worse and 2 were better, whereas 70% of controls got to that stage.
What did Bechara et al., (1999) find about the performance of patients with amygdala and vmPFC damage in the Iowa gambling task?
Controls shift from selection of bad cards to good cards as task progresses.
Patients with amygdala and vmPFC regions persist with drawing from the bad decks.
Both types of patients reach this outcome, but for different reasons: controls have increase in SCR after reward and punishment. vmPFC patients show an increase to both, but the amygdala patients do not show any SCR to reward or punishment.
–> therefore amygdala could be implicated in inducing physiological differences in situations where reward and punishment are at play.
What did Blair (2002) find about the performance of psychopaths on the Iowa gambling task?
Those with Psychopathy perform similarly to patients with vmPFC lesions, and persist in their selection of cards from the back deck(s).
What was found about the performance on the Iowa Gambling Task by those with early vmPFC damage (Anderson, 1999)?
Those with early vmPFC lesions are associated with the same impairments as those sustaining vmPFC damage later in life.
Both patients were impaired on the moral reasoning task. Early onset PFC damage results in a syndrome that resembles psychopathy.
Suggests the PFC, and specifically the vmPFC is required for moral reasoning and affective decision making under ambiguity
Does PFC damage necessarily lead to antisocial and aggressive behaviour (Mataro et al., 2001)?
Some form of cognitive impairments, but nowhere near as dysfunctional as Phineas gage. Had a supportive family - social support acted as a protective factor against ASVB.
So PFC damage may not necessarily lead to ASB.
