The Brain + Theory To Plain Aggression Flashcards
(54 cards)
Aim of Raine’s study
- to investigate whether there were brain differences between violent murderer who had pleaded not guilty by reasons of insanity compared to a matched control group of non murderers using PET scans.
- specifically on seeing any dysfunction in pre frontal cortex which was thought to involve in violent behaviours
Procedure of Raine’s study
- 41 murderers (39 men, 2 women) who had pleaded not guilty by reasons of insanity, charged with manslaughter, 6 are schizophrenic
- matched pair with control groups based on age, gender and mental capacity
- did a practice task then inject radioactive glucose tracer then did 32 minutes continuous performance visual task that suppose to increase brain activity
- PET scan after the task
AO1 Findings of Raine’s study
- murderers had less activity in PFC for self control compared to control group
- less activity in left amygdala and more activity in right amygdala for fear
- more activity in right thalamus for hormones
AO1 conclusion of Raine’s study
- violent behaviours are controlled by areas of brain
- areas with abnormal activity are associated with lacks of fear, lowered self control, increased aggression and impulsive behaviour and problems with controlling and expressing emotions
- indicates a link of abnormal brain activity and predisposition of violence
Function of frontal lobe
- decision making
- self control
- personality
Function of Parietal lobe
- language
Function of temporal lobe
- sensory and auditory
Function of occipital lobe
- visual and sensory
Structure of mid brain
- contains periaqueductal grey matter, links with amygdala and hypothalamus with prefrontal cortex
Role of mid brain
- coordinating and integrating behavioural response to internal and external stimuli e.g. pain or threat
One study supports explanation of mid brain
- Lonstein and stern
= found wen after rats gave birth, had lesions on PAG showed increase in aggression when they faced potential threat, when unfamiliar male rats went near them
Structure of limbic system
- consists of hippocampus, amygdala, hypothalamus
Function of limbic system
- control temperature and flight or fight response
- link with autonomic systems responds automatically without planned
Role of hypothalamus
- maintain homeostasis via the regulation of hormones
E.g. sexual functioning hormones = testosterone can increase aggression
Role of amygdala
- centre of emotions, emotional behaviour and motivation
- in and external stimuli inputs combined with emotions to give us instinctive feelings or reaction to environment e.g. aggression
- PFC link with amygdala that control expression of aggression
One study that supports explanation of amygdala
- Downer
- study on monkeys with one side of amygdala removed
- if monkeys have visual input connecting to intact amygdala = show aggression
- if their visual input cannot reach amygdala = shows calmer
Role of prefrontal cortex
- control social interaction, regulation of behaviour and regulation of emotions
Role of left and right PFC
L- regulates positive emotions
R- regulates negative emotions
Effect of damaging PFC
- problems with anger management
- irritability and impulse control
What study supports explanation of PFC
- Bachara and va der Linden
= PFC seems to regulate behaviour and defer rewards
= damage can means someone only focus on present but unable to plan for future and pursue immediate rewards and less control on aggressive reactions
Pros of using the brain as explanation for aggression
- supported by case study of Phineas Gage
- supported by Raine et al study
Cons of using brain to explain aggression
- criticism of case study supportiveness
- criticism of support from animal research = anthropomorphic
- reductionists
- biological determination
How is using brain explain aggression reductionist ?
- reduces production of aggression behaviour down to working of specific neural circuits
- ignores other explanation e.g. learning
= insufficient
How is biological determination a drawback of brain explanation of aggression ?
- behaviour is predetermined by bio makeup
- no free will to how you behave, small amygdala and low activity PFC are destined to be aggressive
= people are aggressive have no control, as born that way and are not to blame