What makes anti-smoking TV ads effective? Is it flashing images and great editing? A University of Pennsylvania study put public health ads to the test.

Researchers tested two things in participating smokers -- activation in areas of the brain responsible for behavior change and nicotine levels in their urine over time.

They showed participants ads with strong anti-smoking arguments, and ads with weaker arguments. In both categories, some had high production values, others didn't.

What's important?

"Content comes first," summarized psychiatrist Daniel Langleben who conducted the research with An-Li Wang of the Annenberg Public Policy Center at the University of Pennsylvania.

He says strong arguments won out, regardless of production value.

This level of scientific rigor is new in testing the strength of ads.

Langleben says the study has a strong take-away message for public health messaging.

"If you have a limited budget, you have $1,000 to make an ad, your first priority should be coming up with a strong argument, rather than spending a lot of money on special effects," he said.

He says previous advertising research usually tested for how much participants recalled -- but that doesn't really matter with anti-smoking ads. "If you remember an ad or frame from an ad, it doesn't mean anything or much about you changing your behavior," he concluded.

He says testing both brain activation and nicotine levels with smokers gives a clearer picture of what actually prompts behavior change.