Aggression - neural mechanisms! AO1 & AO3 Flashcards
What is the Limbic System made up of?
-neural mechanisms in aggression
H- hypothalamus
A- amygdala
T- thalamus
Hippo- hippocampus
Which part of the Limbic System is most associated with Aggression? Why?
-neural mechanisms in aggression
amygdala
- plays key role in how we assess & respond to environmental threats
- evaluates the emotional importance of sensory info & prompt an appropriate response
- Gospic et al. carried out brain scans (fMRI) on ppts in lab-based game that provoked aggression; scans showed aggressive reactions were associated with a fast & heightened response by the amygdala
What effect did Benzodiazepine drug have in Gospic et al. aggression lab-based game?
-neural mechanisms in aggression
it reduces arousal of the atomic nervous system
so taken before the game halved number of aggressive reactions as it decreased amygdala activity
How is the Limbic System an important predictor of Aggression?
-neural mechanisms in aggression
speed & sensitivity of Limbic System responses to stimuli helps predict aggressive behaviour
What is ‘Proactive Aggression’?
‘cold-blooded’
a planned method of getting what you want
less emotional
e.g. bullying, domination, teasing, name-calling
What is ‘Reactive Aggression”?
‘hoy-blooded’
angry, impulsive reaction accompanied by physiological arousal e.g. temper tantrums, vengeance
-probably responsible for greater no. of society’s problems
Define ‘Neural Mechanisms’
areas of the brain & how they communicate
e. g. neurotransmitters that may be responsible for aggression
e. g. limbic system & serotonin
Define ‘Hormonal Mechanisms’
chemical substances that circulate in the bloodstream & may be in this case responsible for aggression
e.g. testosterone
What is the Limbic System?
-neural mechanisms in aggression
a set of subcortical structures in the brain thought to be closely involved in coordinating & regulating emotional behaviour, including aggression
Role of the Hippocampus?
-neural mechanisms in aggression
role in forming new memories, e.g. converting STM to LTM
memories can evoke emotions
e.g. an animal can compare the conditions of a current threat to similar past experiences (can make them more likely to respond w/ aggression/fear)
Role of Hypothalamus?
-neural mechanisms in aggression
regulates functions in the body, e.g. regulates the autonomic nervous system (ANS)
this system is responsible for fight/flight response
Role of Amygdala?
-neural mechanisms in aggression
when stimulated, can produce feelings of anger, violence, fear & anxiety
if destroyed, it has a mellowing effects on emotions & behaviour
evaluates the emotional importance of sensory info & prompt an appropriate response
greater reactivity/stimulation of it is an important predictor of aggression in humans
Role of Thalamus?
-neural mechanisms in aggression
sensory relay station (so info from senses is coordinated here)
this area then directs info to appropriate areas of the cortex & other parts of brain
senses play important role in emotions (important for regulating emotions)
What is the problem with having Impaired Hippocampal Functioning?
-neural mechanisms in aggression
it prevents the nervous system from putting things into relevant & meaningful context
so the amygdala may respond inappropriately to sensory stimuli, resulting in aggressive behaviour
What is Serotonin?
-neural mechanisms in aggression
an inhibitory neurotransmitter - it slows down neuronal activity
What are normal levels of Serotonin linked with?
-neural mechanisms in aggression
linked with reduced firing of neurones, & so inhibits responses to emotional stimuli (that may others have lead to an aggressive response) in the amygdala
leads to a greater degree of behavioural self-control
What are normal levels of Serotonin associated with?
-neural mechanisms in aggression
associated with a greater degree of behavioural self-control as the orbitofrontal cortex is greatly inhibited
What does low levels of Serotonin mean?
-neural mechanisms in aggression
as Serotonin inhibits the firing of the amygdala, low levels of it removes this inhibitory effect
so therefore people are less able to control impulsive & aggressive behaviour (as the amygdala is highly stimulated)
What are the basics to know about Serotonin?
-neural mechanisms in aggression
serotonin slows down neurone activity
slower neurone activity means inhibited responses to emotional stimuli
Normal Serotonin responses Vs Low Serotonin Responses?
-neural mechanisms in aggression
normal serotonin = behavioural self-control
low serotonin = less behavioural self-control (more aggression)
What is a limitation of the Limbic System explanation?
-EVALUATION of neural mechanisms in aggression
- limitation is that it excludes other possibilities
- the amygdala functions in tandem w/ the orbitofrontal cortex (OFC) to maintain self-control & inhibit aggression
- Coccaro et al. (2007) showed OFC activity is reduced in patients w/ psychiatric disorders that feature aggression
- this shows the regulation of aggression cannot be explained by the limbic system alone - it is highly complex
What is the supporting evidence for the role of Serotonin?
-EVALUATION of neural mechanisms in aggression
- research shows drugs that increase serotonin activity also reduce levels of aggressive behaviour
- Berman et al. (2009) found that ppts given a serotonin-enhancing drug called paroxetine gave fewer & less electric shocks to a confederate than people in a placebo group
- this was only true of ppts who had a prior history of aggressive behaviour, but is evidence of a link between serotonin function & aggression that goes beyond correlation findings
Why is a limitation of the neural explanation for aggression the fact that research is correlational?
-EVALUATION of neural mechanisms in aggression
- because the alternatives are limited - studies w/ humans are impossible for ethical reasons & animal studies raise issues of generalisability to human aggression
- research showing a correlation between serotonin & aggression risks oversimplifying the true mechanisms involved as other factors which influence or even cause aggression are overlooked
- this means that the neural regulation of aggression is almost certainly more complex than our current understanding suggests
What is the limitation of Determinism for the neural explanation of aggression?
-EVALUATION of neural mechanisms in aggression
- determinist as sees aggressive behaviour as governed by internal, biological causes that we have no control over
- has implication for our legal system & wider society, as offenders are seen as legally & morally responsible for their actions
- the links between serotonin & the amygdala in aggression could complicate this principle; may lead to screening of the population to identify this susceptibility & discrimination against those people
- has ethical implications for people w/ such a biological predisposition
- though other psychologists argue that people who discover their predisposition for aggression gives them the opportunity to avoid environmental triggers & help them develop coping mechanisms
How does the case of Charles Whitman support the neural explanation for aggression?
-EVALUATION of neural mechanisms in aggression
- he killed 13 people; left behind note asking doctors to examine his brain as he was convinced something was making him aggressive
- found to have a tumour pressing against his amygdala; supports that amygdala plays an important role in aggression, supporting the validity of the theory
- though is a case study so may not be reliable explanation for all people!
What is the limitation of Reductionism for the neural explanation of aggression?
-EVALUATION of neural mechanisms in aggression
- links between biological mechanisms e.g. serotonin & the amygdala are well established in animals; though not so clear for humans
- thus the complexity of human social behaviour means that a biological/neural explanation for aggression is insufficient on its own & so is reductionist
What is the limitation of ‘Cause & Effect’ for the neural explanation of aggression?
-EVALUATION of neural mechanisms in aggression
- most of the research into neural mechanisms for aggression is correlational
- good ethical implications for this as opportunities to experimentally manipulate brain structures are limited
- however, when 2 variables are correlated, it is impossible to establish which one is the cause of the other, or if extraneous variables are involved
What is the strength of Gospic et al. (2011)’s Research Evidence on the Limbic System for the neural explanation of aggression?
-EVALUATION of neural mechanisms in aggression
- used a well-established lab method of assessing aggressive behaviour called the ‘Ultimatum Game’
- 2 playeres; proposer offers to split money in certain way w/ the Responder, if they accept the money is split as proposed; if reject then both receive nothing
- ppts played as the Responder while having their brains scanned by fMRI; found that when responders rejected unfair offers (an aggressive reaction called social provocation) scans revealed a fast & heightened response by the amygdala
- also found a benzodiazepine drug (reduced arousal of Automatic Nervous System) taken before the game had 2 effects on Responders to unfair offers; it halved the number of rejections (reduced aggression) & decreased the activity of the amygdala
