BLOOMINGTON - Sex on college campuses is nothing new, but an Illinois Wesleyan University professor wants to use the latest technology to find out why students make risky sexual decisions.

The federal government is so interested that it gave IWU researcher Natalie Smoak and a colleague at the University of Connecticut a $1.2 million grant. They will use virtual-reality technology to study how and why people make decisions that could lead to sexually transmitted diseases, including the human immunodeficiency virus.

The grant, from the National Institutes of Health, is the largest grant in the history of IWU, the university an-nounced Tuesday.

"I think the grant is a real indication of how much importance the National Institutes of Health places on STD, HIV and AIDS prevention," said Smoak, an assistant professor of psychology. "This is an important issue."

The U.S. Centers for Disease Control and Prevention estimates that one in four teenagers in the United States have a sexually transmitted disease.

Some IWU students have said in focus groups that they believe STDs are less of a problem on campus because many students are from middle- to upper-middle-class families and they are busy studying. Many students believe that they can look at another student and tell whether he or she has an STD, Smoak said.

"But it's the attractive, popular students who often have the STDs because they are the students that everyone wants to sleep with," Smoak said.

Smoak and Kerry Marsh, associate professor of psychology at the University of Connecticut, have found that surveying students regarding sexual practices is not fruitful because the students may not recall details of their sexual encounter or may not answer honestly.

Following people to parties and observing their behavior is not realistic.

But virtual reality technology may give Smoak, Marsh and the federal government the information they seek.

The grant will be used to set up a virtual reality lab in IWU's Center for Natural Sciences, to develop a computer program to build a virtual reality world, and for computer software, special head-mounted devices or goggles and data gloves, and to hire researchers and pay participants.

Smoak said the grant marks the first time that the federal government will be using virtual reality research to determine whether risky sexual decisions are based on environmental cues or personality. Study results will help the government to decide where to focus its STD prevention efforts.

With the research, which should begin next winter and will involve about 1,000 people, pre-screened participants will go to the lab and put on the special goggles, which will put them in a virtual reality world of a party. They will interact with virtual reality people - who are controlled by researchers - including one who will express an interest in them.

The participant will be put through a variety of scenarios with the virtual reality partner - from deciding whether to leave the loud party for a quiet room to deciding whether to have sex with or without a condom.

Smoak said research in other areas found that people who participate in virtual reality respond as they would in real life.