Structure of brain and aggression

Question 1

Limbic system

Answer 1

• Which involves the amygdala which plays a role in threat perception if things are deemed as threats, makes you more aggressive overall

Question 2

Amygdala

Answer 2

• Processes emotions regulation and motivation, responds to threats and challengers
• This is seen in the Coccaro et al study where it was found people who have extreme reactive aggression show higher levels of amygdala activity when viewing images of angry faces

Question 3

Prefrontal cortex

Answer 3

• Governs social interactions and regulates behaviour and control impulses
• This was seen in Raine et al study where it found murders had much high levels of activation in their amygdala but lower activation in the prefrontal cortex when compared to their matched control

Question 4

Hypothalamus

Answer 4

• To produce the fight or flight response, and it activates two systems, the sympathetic nervous system and the adrenal cortical system
• The sympathetic nervous system makes the body to speed up, tense up and become more alert
• The adrenal cortical system leads to adrenaline to be released which increases heart rate and heavier breathing

Question 5

Serotonin

Answer 5

• A common neurotransmitter with inhibitory effects, normal levels of serotonin are associated with reasonable levels of self-control
• Lower levels of serotonin can lead to lesser levels of self-control and more impulsive behaviours, more aggression
• This is seen in the Virkkunen et al study where it was found that level of serotonin was significantly lower in the spinal fluid of violent and impulsive offenders compared to non-impulsive offenders

Question 6

Dopamine

Answer 6

• A common neurotransmitter that has a lot of effects, one of its effects is regulating behaviour and giving experiences of rewards
• An increased level of dopamine overall increased impulsivity and aggression
• We see that lower levels of serotonin leads to a person being less able to control their impulses and control themselves, this issue can be made worse with an excess of dopamine which makes the person less able to control themselves

Question 7

Strength of brain areas as an explanation for aggression

Answer 7

• Research by Raine et al found that there are structural difference between the brain of impulsive violent murders and controls
• The activity of the prefrontal cortex, limbic system and various other areas are very different when comparing brain scans
• Murders have low activity in the prefrontal cortex and more activity in their amygdala
• This suggests there may be a physical brain based reason that some individuals are more aggressive than others

Question 8

Weakness of brain areas as an explanation for aggression

Answer 8

• An issue with these types of research on brain areas and neurotransmitters is that they are mostly correlation
• It is ethically impossible to intentionally damage brain areas of a healthy person’s brain to measure their changes in aggression
• We cannot establish a cause effect relationship as we can only use animal studies to cause brain changes, with also cause some ethical issues as well
• It is difficult to be sure that other variable aren’t also involved in aggression such as the individual’s upbringing