Brain injury Flashcards
What are the 3 types of brain injuries and how are they caused?
TBI (Traumatic Brain Injury)
Caused by a traumatic fall or car/sports accident
ABI (Acquired Brain Injury) acquired by stroke
Caused by genetic disposition, diet, exercise
ABI (Acquired Brain Injury) acquired through tumour
Caused by genetic disposition, diet, carcinogen exposure
What are the 6 features of the pre-frontal cortex?
Responsible for:
- Decision making
- Forward planning
- Controlling impulses
- Risk-taking behaviour
- Changing behaviour - keeping emotions balanced
Still developing till age 25
How does pre-frontal cortex damage link to crime and anti-social behaviour? (2 points)
Causes personality change - makes people antisocial and aggressive
Impairs people’s decision-making - makes them more likely to commit crimes
What is the orbitofrontal cortex? (2 points)
Prefrontal cortex region involved in cognitive processes
Including decision making, controlling emotions and imagining consequences
Which 4 studies support the link between pre-frontal cortex damage and criminality?
Damasio et al (1994)
Brower and Price (2001)
Volkow & Tancredi (1987)
Fazel et al (2011)
How does Damasio et al (1994) support the link between pre-frontal cortex damage and criminality? (3 points)
They built a 3D computer model of Phineas Gage’s skull, showing that the 4ft rod blasted through and destroyed his left orbitofrontal cortex - TBI
According to his friends, Phineas was dependable and kind before the injury - became irritable, impulsive and anti-social after
Low population validity - not representative of how every individual responds to brain injury
How do Brower and Price (2001) support the link between pre-frontal cortex damage and criminality? (2 points)
They undertook a literature review of documented brain injuries
Found that many case studies show anti-social personalities can arise after frontal lobe injury
How do Volkow & Tancredi (1987) support the link between pre-frontal cortex damage and criminality?
Used PET scans to find out two out of four violent psychiatric patients showed frontal damage
How does Fazel et al (2011) support the link between pre-frontal cortex damage and criminality?
Found that 8.8% of people who experienced an ABI committed a violent crime compared to 3% of the control group
What is the amygdala and what does it do? (3 points)
Small region located in temporal lobes - part of limbic system
Involved in detecting, processing and responding to environmental threats
Processes information from our senses and determines the emotional response to that information (fight-or-flight response)
How does the amygdala relate to criminal psychology? (2 points)
When activated, it overrides the rational part of our brain so that we are less likely to think rationally
Damage to it can cause people to respond to threatening situations in extreme ways - causes people to spontaneously act aggressive
What are the 3 studies supporting the amygdala linking to criminal behaviour?
Yang et al - small amygdala volume
Glenn et al - psychopaths in moral decision making
Pardini et al - amygdala volume and violence
How does Yang et al support the amygdala linking to criminal behaviour? (3 points)
They found using structural MRI scans that psychopaths had smaller-volume amygdalas when compared to a control group
17.1% smaller in the left and 18.9% on the right
Significant correlations between the lowered volume of amygdala and higher psychopathy scores
How does Glenn et al support the amygdala linking to criminal behaviour? (2 points)
They used fMRI scanning to find out that ‘psychopathic’ individuals had reduced amygdala activity during moral decision-making compared to a control group
Suggests that psychopaths show deficits in brain regions related to moral reasoning, causing them to worry less about causing harm to others
How does Pardini et al support the amygdala linking to criminal behaviour? (2 points)
They conducted neuroimaging scans and grouped 26-year-old men into either a group of ‘normal-volume’ or ‘reduced-volume’ amygdalas.
3 years later, the reduced-volume group were 3 times more likely than the others to be aggressive, violent and show psychopathic traits
How does Raine et al support pre-frontal cortex and amygdala damage linking to criminal behaviour? (3 points)
They found from using PET scans that NGRI people had less glucose activity in the prefrontal area - 1.09 - compared to controls - 1.12
NGRIs had imbalances in amygdala activity - the left side had lower activity than control and the right side had higher activity than control
Therefore there are abnormalities in how NGRIs detect, process and respond to environmental threats (fight or flight response)
How is brain injury as an explanation for criminality reductionist? (3 points)
Neurologist James Fallon used his own MRI brain scan as a control
Identified his amygdala as one of a psychopath - he is a successful scientist and family man
Suggests that the explanation is reductionist - there are other factors contributing to criminal behaviour
What is the alternative explanation other than brain injury for crime and anti-social behaviour? (2 points)
Social Learning Theory - suggests criminality is learnt through aggressive role models being observed and imitated due to vicarious reinforcement
Bandura (1961) found boys observing an aggressive role model increased the number of imitated aggressive behaviours (25.8) compared to observing a non-aggressive one (1.5)
