The kid who stole everybody's lunch money may have a different brain structure than the hungry victims. Using functional MRI, researchers giving a report at the RSNA meeting also found that adolescents with disruptive behavior disorder (DBD) respond differently to violent video games than do normal adolescents.
"We have preliminary evidence demonstrating that adolescents with DBD have different brain structure and brain activation patterns than nonaggressive adolescents," said principal investigator Dr. Vincent P. Mathews, chief of neuroradiology at Indiana University School of Medicine.
The study used fMRI outfitted with high-speed gradients to look for rapid changes in blood flow in the brain. It found that the subjects with DBD had less brain activation when they watched violent video games in the frontal lobes, which are involved in emotional control and response inhibition.
Researchers also used diffusion tensor images to show microstructural differences in the brains of aggressive and nonaggressive adolescents. The process forces water to move in different directions in the brain, allowing researchers to get a clear picture of the integrity of white matter. This technology is rapidly becoming available in clinical instruments, Mathews said.
The study exposed two groups of 19 adolescents with and without DBD to a car-chase game that is exciting without being violent and a James Bond game that contains a lot of violence. Researchers saw a difference in brain function in the control group depending on how much violent media they had been exposed to. They did not, however, observe a difference in brain structure with short-term exposure to violent media.
Mathews suggested that fMRI may eventually play a role in gauging the effects of psychiatric or psychological treatment of aggressive adolescents.
"The next step is evaluating treatment. We will look at the interventional effects to determine if they have changed the way the brain functions. It may be that the brain will normalize after treatment," he said.
