New Study Examines Impact of Violent Media on the Brain
Exposure to violence has a different effect on people with aggressive traits
With the longstanding debate over whether violent movies cause real world violence as a backstop, a study published today in PLOS One found that each person’s reaction to violent images depends on that individual’s brain circuitry, and on how aggressive they were to begin with.
The study, which was led by researchers at the Icahn School of Medicine at Mount Sinai and the NIH Intramural Program, featured brain scans which revealed that both watching and not watching violent images caused different brain activity in people with different aggression levels. The findings may have implications for intervention programs that seek to reduce aggressive behavior starting in childhood.
“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. “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.”
After answering a questionnaire, a group of 54 men were split by the research team into two groups—one with individuals possessing aggressive traits, including a history of physical assault, and a second group without these tendencies. The participants’ brains were then scanned as they watched a succession of violent scenes (shootings and street fights) on day one, emotional, but non-violent scenes (people interacting during a natural disaster) on day two, and nothing on day three.
The scans measured the subjects’ brain metabolic activity, a marker of brain function. Participants also had their blood pressure taken every five minutes, and were asked how they were feeling at 15 minute intervals.
Investigators discovered that during mind wandering, when no movies were presented, the participants with aggressive traits had unusually high brain activity in a network of regions that are known to be active when not doing anything in particular. This suggests that participants with aggressive traits have a different brain function map than non-aggressive participants, researchers said.
Interestingly, while watching scenes from violent movies, the aggressive group had less brain activity than the non-aggressive group in the orbitofrontal cortex, a brain region associated by past studies with emotion-related decision making and self-control. The aggressive subjects described feeling more inspired and determined and less upset or nervous than non-aggressive participants when watching violent (day 1) versus just emotional (day 2) media. In line with these responses, while watching the violent media, aggressive participants’ blood pressure went down progressively with time while the non-aggressive participants experienced a rise in blood pressure.
“How an individual responds to their environment depends on the brain of the beholder,” said Dr. Alia-Klein. “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. 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.”
This study was conducted with the additional partnership from researchers at the Department of Applied Mathematics and Statistics, SUNY, in Stony Brook, New York, and the Medical and Chemistry Departments at Brookhaven National Laboratory in Upton, New York.
About the Mount Sinai Health System
The Mount Sinai Health System is New York City's largest integrated delivery system, encompassing eight hospitals, a leading medical school, and a vast network of ambulatory practices throughout the greater New York region. Mount Sinai's vision is to produce the safest care, the highest quality, the highest satisfaction, the best access and the best value of any health system in the nation. The Health System includes approximately 7,480 primary and specialty care physicians; 11 joint-venture ambulatory surgery centers; more than 410 ambulatory practices throughout the five boroughs of New York City, Westchester, Long Island, and Florida; and 31 affiliated community health centers. The Icahn School of Medicine is one of three medical schools that have earned distinction by multiple indicators: ranked in the top 20 by U.S. News & World Report's "Best Medical Schools", aligned with a U.S. News & World Report's "Honor Roll" Hospital, No. 12 in the nation for National Institutes of Health funding, and among the top 10 most innovative research institutions as ranked by the journal Nature in its Nature Innovation Index. This reflects a special level of excellence in education, clinical practice, and research. The Mount Sinai Hospital is ranked No. 14 on U.S. News & World Report's "Honor Roll" of top U.S. hospitals; it is one of the nation's top 20 hospitals in Cardiology/Heart Surgery, Diabetes/Endocrinology, Gastroenterology/GI Surgery, Geriatrics, Gynecology, Nephrology, Neurology/Neurosurgery, and Orthopedics in the 2019-2020 "Best Hospitals" issue. Mount Sinai's Kravis Children's Hospital also is ranked nationally in five out of ten pediatric specialties by U.S. News & World Report. The New York Eye and Ear Infirmary of Mount Sinai is ranked 12th nationally for Ophthalmology and the South Nassau Communities Hospital is ranked 35th nationally for Urology. Mount Sinai Beth Israel, Mount Sinai St. Luke's, Mount Sinai West, and South Nassau Communities Hospital are ranked regionally.