Neural Explanations

Question 1

Neural Mechanisms

The limbic system

Answer 1

• Papez (1937) linked the limbic system to emotional behaviours such as aggression.
• Includes the hypothalamus, amygdala and parts of the hippocampus.
• The reactivity of the amygdala is a predictor of aggressive behaviour, illustrated by Gospoic (2011)
• Participants were mildly provoked and where they reacted aggressively fMRI scans shows a fast and heightened response.
• A drug that reduces arousal of ANS decreased activity of amygdala and halved the number of rejections.

Question 2

Neural Mechanisms

Orbitofrontal cortex and serotonin

Answer 2

• Serotonin has inhibitory effects on the brain.
• Normal levels are linked with reduced firing of neurons and greater behavioural self-control.
• Decreased serotonin reduces self control and leads to an increase in impulsive behaviour.
• Virkkunen (1994) compared levels of serotonin breakdown product in the cerebrospinal fluid of violent impulsive and violent non-impulsive offenders.
• Levels were significantly lower in impulsive.

Question 3

Neural Mechanisms: Evaluation

Non-limbic structures

Limitation

Answer 3

• Recent research has shown non-limic structures are involved in aggression.
• Limbic systems work alongside the orbitofrontal cortex (not part of the system)
• OFC works on impulsive regulation and activity is reduced in psychiatric disorders that featuer aggression.
• This reduced activity disrupts the impulse-control function of the OFC and increases aggression

This shows neural regulation of aggression is more complex than amygdala theories suggest.

Question 4

Neural Mechanisms: Evaluation

Paroxetine and Serotonin

Strength

Answer 4

• Serotonin prodives research into the effects of drugs on aggression.
• Drugs that increase serotonin reduce levels of aggressive behaviour.
• Bomen (2009) had participants take a drug or placebo then take part in a game involving electric shocks for provocation.
• The parotoxetine group gave consistently fewer shocks and the placebo control group.

This evidence suggests a causal link between serotonin and aggression.