Aggression L1 Neural Mechanisms

Question 1

What are Neural Mechanisms?

Answer 1

• Structures such as neurons, neural circuits and regions of the brain
• These are also substances such as neurotransmitters and hormones

Question 2

What is the Limbic System and its relation to aggression?

Answer 2

• structures such as the amygdala, hypothalamus and hippocampus
• These are all implicated in reactive aggression, in response to a perceived threat, rather than proactive, which is planned in anticipation for a reward
• Limbic System also connects to the cingulate gyros which is responsible for focusing attention on emotionally significant events

Question 3

What does the Limbic System have connections to that is extremely significant?

Answer 3

• Connections to the prefrontal cortex which is involved in forward planning and anticipation of reward
• Limbic System therefore play a key role in our response to environmental threats and challenges, it is a key factor in determining whether we respond aggressively or not to an external stimulus

Question 4

How is the hypothalamus involved?

Answer 4

• Responsible for the regulation of the autonomic nervous system which regulates responses to emotional circumstances
• Damage to this area can result in inappropriate aggressive responses to a perceived threat

Question 5

How is the amygdala involved?

Answer 5

• Amygdala attaches emotional significance to sensory information
• Due to the limbic system being hierarchal with signals being passed from lower systems to higher symptoms in the prefrontal cortex
• This monitors and interprets feelings to trigger a physical response

Question 6

How is the prefrontal cortex involved ?

Answer 6

• Crucial for regulating social behaviour and aggressive responses
• Damage reduces the inhibition of the amygdala, resulting in higher levels of aggression

Question 7

What is the Neurotransmitter Serotonin and how does this work under normal circumstances?

Answer 7

• A Neurotransmitter that has widespread inhibitory effects in the brain, slowing down and calming neural activity
• Under normal circumstances it works in the frontal areas of the brain and inhibits the firing of the amygdala which is part of the limbic system, controlling emotional responses

Question 8

How can serotonin be linked to aggression?

Answer 8

a low level of serotonin where people cannot control their impulsive and aggressive behaviours

Question 9

How does serotonin in the prefrontal cortex link to aggression?

Answer 9

• Serotonin regulates the prefrontal cortex, meaning lower levels of serotonin affect our response to external stimuli
• The person therefore becomes aggressive easily and can’t control their responses in a ‘normal’ way
• They struggle to anticipate risk and act impulsively in aggressive behaviour

Question 10

What are Strengths of Neural Mechanisms in Aggression? (3)

Answer 10

• Monkey removal
• MRI scans
• Serotonin in rats

Question 11

Monkey removal (+)

Answer 11

• Removed key parts of the limbic system, e.g amygdala, hippocampus and cortical areas in Rhesus Monkeys
• Monkeys displayed an absence of emotional, motor and vocal reactions to stimuli which were meant to incite fear and danger
• They also tried to fight much larger members of the group, losing all sense of social hierarchy, showing the importance of the limbic system in aggression

Question 12

MRI scans (+)

Answer 12

• Undertook MRI scans of 19 violent male criminals in Broadmoor hospital and compared this to 20 control subjects who were not violent criminals
• The volume of the amygdala was found to be significantly smaller in the 19 violent criminals, showing the role of the amygdala and limbic system in aggression

Question 13

Seretonin in rats (+)

Answer 13

• Allowed adult male rats to fight with one another at a specific time for 10 days
• 11th day rat was not allowed to fight, dopamine levels had increased by 65% and serotonin levels had reduced by 35%
• Despite the rat not fighting, the brain chemistry had altered showing the implications of neurotransmitters in aggression

Question 14

What are Weaknesses of Neural Mechanisms in Aggression? (3)

Answer 14

• Heavy use of animal research
• Gender differences
• Biological Reductionism

Question 15

Heavy use of animal research (-)

Answer 15

• A lot of evidence for neural mechanisms is through the use of animal studies
• This poses problems as humans do not function in the same way, despite having similar systems, e.g limbic system in rhesus monkeys
• Cannot extrapolate the behaviours of animals to humans, we are far more complex

Question 16

Gender differences (-)

Answer 16

• Administered the drug dexfenfluramine to 35 healthy adults, this drug lowered serotonin in the brain
• Researchers used a questionnaire to assess hostility and aggression levels
• Aggression rose in males, but not in females, showing that there is a difference between genders neural mechanisms when talking about aggression
• This shows beta bias, and that males and females may not be subject to the same psychological factors when explaining aggression

Question 17

Biological Reductionism (-)

Answer 17

• Focuses on the sole biology, not other explanations and the use of other factors in aggression