Neural And Hormonal Mechanisms Flashcards
What are the 2 neural mechanisms
- Limbic system
- Serotonin
What is the limbic system
A network of brain structure involved in regulating emotional responses such as fear and aggression
What are the 4 components of the limbic system
- Hypothalamus
- Thalamus
- Amygdala
- Hippocampus
What is the role of the amygdala
Increase blood pressure and adrenaline which can result in aggressive behaviour
What happened when the amygdala was electrically stimulated in rats?
The rats responded with aggression, but when it was removed, the animal is tamed and does not show the expected ‘rage’ reactions when provoked
What does the amygdala show about excess activation
Excess activation can explain aggressive behaviour
In non - aggressive people it doesn’t become activated when a threat is insignificant.
What is the role of the hippocampus
- Involved in the memory and works alongside the amygdala
- learn what is considered dangerous from previous experiences ans store this in our LTM
What happens when the hippocampus is functioning normally?
Recognises a previously learned threat and signals to the amygdala to respond appropriately
What happens if the hippocampus is damaged
Can cause the amygdala to respond inappropriately to sensory stimuli, resulting in aggressive behaviour
What type of neurotransmitter is serotonin?
An inhibitory neurotransmitter - slows down neuronal activity
What is serotonin involved in?
The regulation of mood, sleep, arousal, appetite
What does normal levels of serotonin cause?
Normal levels in the orbifrontal cortex are linked with behavioural self-control and produces a calming affect on behaviour
What does low levels of serotonin cause
- Low levels in the orbitofrontal cortex are thought to increase aggressive behaviour
- affecting the individuals response to external stimuli
- the person becomes easily provoked and can’t control their responses in a ‘normal way’
- they act impulsively and engage in aggressive behaviour
What is an example of a hormonal mechanism
Testosterone
What is testosterone
- a male sex hormone (androgen) required for the development of secondary sexual characteristics in males such as:
Increase in muscle and bone mass
Growth of body hair
How much more testosterone do males have than women
Men have 20 times more than women
Statistically when are males more likely to commit violent crimes
During adolescence and early adulthood when testosterone levels are at their highest
What have animal studies shown regarding testosterone
- castration typically reduced levels of aggression
Injection of synthetic testosterone reinstates the aggressive behaviour
