Washington, Oct 19 (ANI): A new research has shown that watching violent films, TV programmes or video games desensitises teenagers, blunts their emotional responses to aggression and potentially promotes aggressive attitudes and behaviour.
Lead author Dr Jordan Grafman, senior investigator at the National Institute of Neurological Disorders and Stroke, National Institutes of Health (Bethesda, USA), and colleagues recruited 22 boys between the ages of 14-17 to the study. The boys each watched short, four-second clips of violent scenes from 60 videos, arranged randomly in three lots of 20 clips. The degree of violence and aggression in each scene was low, mild or moderate, and there were no extreme scenes. They were asked to rate the aggression of each scene by pressing one of two response buttons at the end of each clip to say whether they thought it was more or less aggressive than the previous video.
The boys were positioned in a magnetic resonance imaging scanner that collected data on their brain function while they watched the videos. They also had electrodes attached to the fingers of their non-dominant hand to test for skin conductance responses (SCR). This is a method of measuring the electrical conductance of the skin, which varies with moisture (sweat) levels and is a sensitive way of measuring people's emotions and responses to internal or external stimuli.
Dr Grafman said: "We found that as the boys were exposed to more violent videos over time, their activation in brain regions concerned with emotional reactivity decreased and that was reflected in the data from the functional MRI and in the skin conductance responses."
Data from the SCR showed that the boys became more desensitised towards the videos the longer they watched them and also that they were more desensitised by the mildly and moderately violent videos, but not the ones that contained a low degree of violence. Data on brain activation patterns showed a similar effect.
In particular, the area known as the lateral orbitofrontal cortex (lOFC), which is thought to be involved in emotions and emotional responses to events, showed increasing desensitisation over time, and this was most marked for the most aggressive videos (showing moderate violence) in the study.
The researchers also found that boys who had the most exposure to violent media in their daily lives, as measured by screening tests and questions in their initial meeting with the researchers, showed the greatest desensitisation.
The study has been published online in the Oxford Journal Social Cognitive and Affective Neuroscience. (ANI)