Biological Explanations Flashcards
Affective Empathy
The ability to faithfully recreate the emotional context of an event that you witness
Cognitive Empathy
The ability to understand or describe other people’s feelings
Personality Change via Brain Damage
- Phineas Gage 1848
- Railway worker - catastrophic damage to prefrontal lobes caused by metal pole going through cheek into breain
- Recovered physically - went from being sober family man to violent drunk
- Prefrontal lobes keep behaviour in check, moderate impulses
Adrian Raine (2009) - Neural Study
- Compared 27 non-criminal psychopaths to 32 non-psychopaths
- Psychopaths = 18% vol reduction in amygdala, 11% reduction in gray matter of PFC & ACC
Mirror Neurons
- Brain cells that fire when you do an action or watch someone else do the same action
- Important for vicarious reinforcement and infant IWM development
- Require use to work normally
- Show deficits in conditions like ASD & APD
Geysers et al (2011) - Mirror Neurons
- When asked to empathise, APDs did
- Mirror neurons activated
- APDs empathy = sporadic v ‘normal’ brain - empathy always on
CDH13 (gene) & Cadherin (protein) in non-criminals
- Slows down axon growth when neurons change structure/type - negative regulation helps conserve energy and speed up change
- Slows down natural death of vascular cells around neurons during periods of stress
- Natural defence against atherosclerosis and harmful stress
- In very low activity state in some types of cancer development
CDH13 & Cadherin in Criminals
- Believed that high activity of CDH13 interrupts building and strengthening of some neural networks during their development
- Childhood stress/trauma may acetylate this gene
- Some networks may end up less well-developed or connected
- Produces Bowlby’s Affectionless Psychopathy
Monoamine Hypothesis
- Monoamines = Group of NTs (eg. dopamine, serotonin)
- After they are received, enzyme MAO-A is used to break them down (catabolysis)
- Production of MAO-A controlled by MAOA gene
- Lacking MAO-A - unable to reduce monoamine levels at normal rate
- MAOA also on X chromosome - men at increased risk as they can inherit it from the mother
Brunner (1993): Aim
To explain the behaviour of a large family in the Netherlands where the males are affected by a syndrome of borderline mental retardation and abnormal violent behaviour
Brunner (1993): Method and Behavioural Examination
Clinical examination of male family members and comparison with normal family members
Behavioural Examination
* Repeated episodes of aggressive and sometimes violent behaviour
* Sleep disturbances and night terrors
* Arson
* Inappropriate sexual behaviours towards sisters and female relatives
Brunner (1993): Findings
- All 9 affected males intellectually retarded (delayed or interrupted intellectual development, avg IQ 85, only 7 finished primary)
- All unaffected males attended school and were employed
- All females, including carriers, appeared normal
- All affected males showed genetic mutations in MAOA gene
Brunner (1993): Explanation
- MAO-A breaks down and removes noradrenaline (arousal), dopamine (emotional arousal), serotonin (sleep)
- Lower activity levels of MAO-A = increased levels of these NTs
- Males in this family likely to have suffered from increased serotonin, which may have caused their criminal behaviours - impacts control
- Known as Brunner Syndrome
Virkunnen et al (1994)
Violent criminals whose violence was compulsive had lower levels of serotonin than violent criminals whose crime was planned
Beggard et al (2003)
Serotonergic Dysfunction linked to criminal behaviour
