An important brain area involved in making moral decisions lights up in scans when killing a person is not justified, a study where participants played violent video games has found.
The findings show that the neural mechanisms that are typically implicated with harming others become less active when the violence against a particular group is seen as justified.
Participants in the new study played video games in which they imagined themselves to be shooting innocent civilians (unjustified violence) or enemy soldiers (justified violence).
Their brain activity was recorded via functional magnetic resonance imaging (fMRI) while they played.
Dr Pascal Molenberghs from the Monash University said the results provided important insights into how people in certain situations, such as war, are able to commit extreme violence against others.
"When participants imagined themselves shooting civilians compared to soldiers, greater activation was found in the lateral orbitofrontal cortex (OFC), an important brain area involved in making moral decisions," Molenberghs said.
"The more guilt participants felt about shooting civilians, the greater the response in the lateral OFC. When shooting enemy soldiers, no activation was seen in lateral OFC," said Molenberghs.
"The findings show that when a person is responsible for what they see as justified or unjustified violence, they will have different feelings of guilt associated with that - for the first time we can see how this guilt relates to specific brain activation," Molenberghs added.
The researchers hope to further investigate how people become desensitised to violence and how personality and group membership of both perpetrator and victim influence these processes.
The study is published in the journal Social Cognitive and Affective Neuroscience.
