Search Here

Parents, caregivers and other authoritative figures have often worried that violent media, such as movies or video games can negatively impact young people's brains. In a new study, researchers set out to examine how violence affects people. The team reported that the effects of violent images depend greatly on people's unique brain circuitry and their levels of aggressiveness.

"Our aim was to investigate what is going on in the brains of people when they watch violent movies," said lead investigator Nelly Alia-Klein, PhD, Associate Professor of Neuroscience and Psychiatry at the Friedman Brain Institute and Icahn School of Medicine at Mount Sinai reported in the press release. "We hypothesized that if people have aggressive traits to begin with, they will process violent media in a very different way as compared to non-aggressive people, a theory supported by these findings."

For this study, the researchers recruited 54 men who were divided into two groups. The first group included men with aggressive traits based off of their history of physical assault. The second group involved men who did not have these tendencies. The men had their brains scanned on three different days. During day one, they watched violent scenes, such as shootings and street fights. On day two, they watch a non-violent, emotional scene and on the last day, they watched nothing.

Along with the brain scans, which measured the brain's metabolic activity, the team recorded the men's blood pressure every five minutes. The researchers also asked the participants how they felt during 15-minute intervals.

The researchers found that on day three, the participants' brains tended to wander since there were not scenes to watch. In the participants with more aggressive tendencies, their brain scans revealed more activity in comparison to the brain scans of the participants that did not have aggressive tendencies. This difference suggested that men with aggressive traits have different brain circuitry from men without these traits.

When the participants were watching the violent scenes, the aggressive men had less brain activity in the orbitofrontal cortex than the men from the control group. This region of the brain has been linked to emotion-related decision-making and self-control. Furthermore, the aggressive group reported feeling more inspired and less nervous in comparison to the non-aggressive group when watching the violent scenes as opposed to the non-violent, emotional scene.

The team added that blood pressure fell gradually for the aggressive men when they watched the violent scenes. Blood pressure readings for the non-aggressive men on day one, however, spiked.

"Aggression is a trait that develops together with the nervous system over time starting from childhood; patterns of behavior become solidified and the nervous system prepares to continue the behavior patterns into adulthood when they become increasingly coached in personality. This could be at the root of the differences in people who are aggressive and not aggressive, and how media motivates them to do certain things," Dr. Alia-Klein said. "Hopefully these results will give educators an opportunity to identify children with aggressive traits and teach them to be more aware of how aggressive material activates them specifically."

The study was published in PLOS ONE.