This study by Irwin and Gross (1995) came up in one of my classes. They had the kids play games and then put them in a frustrating situation. Is this the kind of thing you're looking for? Anyway, here's the abstract:
"Examined the impact of violent video games on the behavior of impulsive and reflective children. 60 7-8 yr old boys were categorized as reflective or impulsive according to their responses on the Matching Familiar Figures Test. In a factorial design, Ss then played video games with aggressive or nonaggressive themes. Interpersonal aggression and aggression toward inanimate objects were assessed in a free-play setting, and interpersonal aggression was assessed during a frustrating situation. Results indicate that Ss who played the video game with aggressive content exhibited significantly more object aggression during free-play and more interpersonal aggression during the frustrating situation than youngsters who played nonaggressive video games. Aggressive behavior was unaffected by cognitive tempo. "
The title is "Cognitive tempo, violent video games and aggressive behavior in young boys" and it was in the Journal of Family Violence.