Do you feel inspired while watching an action movie or do you feel nervous and fidgety? Your reaction to violent images depends on how aggressive you are and how your individual brain is wired, or so say researchers from Icahn School of Medicine at Mount Sinai. Their new study, based on brain scans, shows how watching violent images inspired different patterns of brain activity in men of varying levels of aggression.

The Singular Orbitofrontal Cortex

Classical studies of the orbitofrontal cortex, which lies in the bottom forward section of your brain’s frontal lobe, proposed this distinct region of the brain to be responsible for social adjustment, self-control, and the regulation of mood, drive, and responsibility. However, later studies indicated memory, reward, and decision-making mechanisms also occur in this brain space, while the most recent research suggests the area may be crucial to information processing. One function of the orbitofrontal cortex may be to inhibit unwanted, distracting, or uncomfortable information or sensations while we form a decision, some scientists believe.

For the current study, the researchers recruited 54 men as participants and then divided them into two groups after all had answered a questionnaire. One group included the men with aggressive traits (as verified by a history of physical assault), the second group included men lacking these tendencies. Then, all the participants' brains were scanned as they watched a succession of clips from violent movies (shootings and street fights). The scans measured the metabolic activity in each man’s brain. Participants also had their blood pressure taken every five minutes, and were asked how they were feeling at 15-minute intervals. The following day, the researchers scanned their brains again as the men watched clips from emotional movies (non-violent scenes of people interacting during a natural disaster). Finally, on a third day, the researchers scanned while the men watched nothing at all.

What did the researchers observe? The scans of the aggressive men when idle showed unusually high brain activity in a network of regions known to light up whenever people are not doing anything in particular. Based on this finding, the researchers believe participants with aggressive tendencies have already developed a different brain function map compared to that of their non-aggressive counterparts. While watching scenes from violent movies, the aggressive men also showed less activity in their orbitofrontal cortexes compared to the non-aggressive men. They also described feeling more inspired and determined and less upset or nervous than the non-aggressive men while watching either the violent or emotional movie clips. And, while watching the violent scenes, the aggressive men’s blood pressure went down while the non-aggressive men experienced a rise in blood pressure.

While many people believe violent movies can cause real world savagery, the study’s results imply such films may indeed exert some influence — but only on those men who have demonstrated aggressive tendencies in the past. "How an individual responds to their environment depends on the brain of the beholder," lead study author Nelly Alia-Klein said.

Source: Alia-Klein N, Wang G-J, Preston-Campbell RN, et al. Reactions to Media Violence: It’s in the Brain of the Beholder. PLOS ONE. 2014.