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Unit 2- Aggression and the structure of the brain :star: - Coggle Diagram
Unit 2- Aggression and the structure of the brain
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Evaluation
:red_cross: A weakness is correlational research.a study will find links between high levels of aggression and a brain function, dysfunction or structure, perhaps by using FMRI scans. One alternative is using animal studies however it raises practical and ethical issues. Therefore ti is impossible to establish whether a particular structure of function is a cause or effect of aggressive behavior, or whether a third variable is involved.
:check: A strength is that it has application to understand aggression. A category of serotonin agonist drugs has been found to have significant anti-aggressive effects in animals and humans. This may be invaluable given that human aggression is at the root of so many personal, social and economic costs,
:check: A strength is it has support from longitudinal research. dustin identified 56 males who had been part of a study 20 years earlier. Over the 20 years these men has consistently behaved aggressively, including being involved in serious criminal violence. Using FMRI brain scans, the researchers found a strong negative correlation between levels of aggression and amygdala volumes. This is a strength because it supports the influence of the amygdala, especially as it shows the explanation has predictive validity.
:check: A strength is that some researchers have attempted to overcome this problem by using drugs known to increase serotonin activity. Participants given paroxetine gave fewer and less intense electric shocks to others. This is evidence of a link between serotonin and aggression that goes beyond the usual correlational findings.
Role of the limbic system
A researched studied people with intermittent explosive disorder. The participants brains were scanned by FMRI while they viewed image of faces.
IED participants showed high level of amygdala activity when viewing imaged of angry faces, a response not found in non-IED controls. This evidence of an association between amgdala reactivity and aggression is especially meaningful because an angry facial expression is an ecologically valid sign of threat.
The key structure involved in aggression is the amygdala. This has a central in how an organism assesses and responds to environmental threats and challenges
Role of serotonin
A researcher compared levels of a serotonin breakdown product in the cerebrospinal fluid of violent impulsive and non-impulsive offenders, The levels were significantly lower in the impulse offenders, who also suffered from more sleep irregularities. This is a particularly interesting finding because serotonin helps to regulate more sleep irregularities,
Serotonin is a neurotramitter with widespread inhibitory effects on transmission between neurons in the brain. Normal levels of serotonin in the OFC re associated with a reasonable degree of behavioral self-control.
Role of the prefrontal cortex
The OFC plays an important ride in higher cognitive functions such as rational thinking and decision-making involved in self-control, impulse regulation and inhibition of aggressive behaviors
Adrian used PET scans to study murderers whose crimes included element reactive aggression. They found greater glucose metabolism in the amygdala, but abnormally low metabolism in the prefrontal cortex, compared with a group of matched controls
Recent research indicates that the amygdala does not operate in isolation in determining aggression. It appears to function in tandem with the orbitofrontol cortex.
Role of dopamine
It is involved in regulating motivated behavior and our experience of reward. According to dong ju see et al, serotonin underactivity stimulates dopamine overactivity and both are linked with impulsivity and aggression
So serotonin hypo function is the primary cause of impulsive aggression
Dopamine is a neurotransmitter that has inhibitory effects in some areas of the brain