I worked at the CDC in Web development for about 8 years when I lived in Atlanta. The Centers for Disease Control and Prevention (CDC) deals with public health, not health care.
Public health concerns disease and chronic condition prevalence by region. It also concerns prevalence of behaviors that lead to potential health problems (like riding a motorcycle without a helmet). This is how the Senate uses CDC's services to investigate the potential ties between video game violence and real world violence.
I'm in total agreement with MTV (Molly, Tom & Veronica), $90 million is a lot of taxpayer money to spend on such a frivilous cause. And I doubt video game violence brings about any violence that is not already in place and that would emerge anyway.
Governments should not market nor legislate morality.
<Mike steps down from soapbox>

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic