New research has shown that graphic warning labels on cigarette packs improve recall of health warnings about smoking.

Some 200 people participated in the study. More than 80 percent were able to remember a graphic warning rather than a text based warning.

The researchers used eye-tracking technology to see how the participants see the graphic message. The longer the participant sees a message, the higher the impact of the message will be on information recall.

Also, the participants had to re-write the warning label text to show how much of it they actually remembered.

"An important first step in evaluating the true efficacy of the warning labels is to demonstrate if smokers can correctly recall its content or message. Based on this new research, we now have a better understanding of two important questions about how U.S. smokers view graphic warning labels: do smokers get the message and how do they get the message," said lead author of the new study Andrew A. Strasser, PhD, associate professor at Department of Psychiatry at Penn.

"In addition to showing the value of adding a graphic warning label, this research also provides valuable insight into how the warning labels may be effective, which may serve to create more effective warning labels in the future. We're hopeful that once the graphic warning labels are implemented, we will be able to make great strides in helping people to be better informed about their risks, and to convince them to quit smoking," said Strasser.

According to a related study, graphic warnings on cigarette packs may help lower smoking among teenagers.

An Australian study also said that graphic warnings are more effective than text based warnings on cigarette packs.

In the U.S., cigarette packs will be required to have a graphic based warning starting this September. The tobacco companies are challenging this rule in the court.