Only recently have investigations of the relationship between media violence exposure (MVE) and aggressive behavior focused on brain functioning. In this study, we examined the relationship between brain activation and history of media violence exposure in adolescents, using functional magnetic resonance imaging (fMRI). Samples of adolescents with no psychiatric diagnosis or with disruptive behavior disorder (DBD) with aggression were compared to investigate whether the association of MVE history and brain activation is moderated by aggressive behavior/personality. Twenty-two adolescents with a history of aggressive behavior and diagnosis of either conduct disorder or oppositional-defiant disorder (DBD sample) and 22 controls completed an emotional Stroop task during fMRI. Primary imaging results indicated that controls with a history of low MVE demonstrated greater activity in the right inferior frontal gyrus and rostral anterior cingulate during the violent word condition. In contrast, in adolescents with DBD, those with high MVE exhibited decreased activation in the right amygdala, compared with those with low MVE. These findings are consistent with research demonstrating the importance of fronto-limbic structures for processing emotional stimuli, and with research suggesting that media violence may affect individuals in different ways depending on the presence of aggressive traits.
The extent to which exposure to media violence increases aggressive and violent behaviors across age and gender has been the subject of decades of research and debate (Bandura et al., 1963, Anderson and Bushman, 2001, Huesmann et al., 2003 and Bushman and Huesmann, 2006). Increases in the popularity, availability, and variety of violent media (e.g., television and video games) necessitate an understanding of how such exposure may affect both behavior and cognitive functioning (Kronenberger et al., 2005a). The General Aggression Model (GAM) posits that long-term exposure to violent media content alters internal states (arousal, cognition, and affect), leading to consolidation of aggressive mental schemas (Anderson and Bushman, 2001 and Carnagey et al., 2007). Empirical support for the GAM emerged from research showing that viewing violence on television increases aggressive thoughts, feelings, and behaviors (Anderson and Bushman, 2001). In addition, individuals who play violent computer/console games also exhibit an increase in short-term aggressive behaviors (Uhlmann and Swanson, 2004, Bartholow et al., 2005 and Carnagey and Anderson, 2005), long-term aggressive traits (Lemmens et al., 2006), and desensitization as measured by a reduced P300 event-related brain potential to violent images (Bartholow et al., 2006).
