Aspiring doctors can now spend a semester and summer at the Yale School of Medicine during their undergraduate years.

Next semester the School of Medicine’s Child Study Center will launch the revamped Yale Directed Research Program — a semester of study and a summer internship at the Child Study Center that allows undergraduate students to gain laboratory research experience prior to applying to medical school. The program, which until this year had been restricted to summer research, was expanded to increase the depth of study that interns could achieve during their time in New Haven. Although the program will only admit two or three students this year, administrators said they have plans to expand in the future.

The original program — introduced 15 years ago by child psychiatry professor Linda Mayes — was an eight-to-ten week summer internship researching child psychology at the Child Study Center on South Frontage Road. Mayes said the program was targeted at undergraduates from small liberal arts colleges, like her alma mater Sewanee, who are not offered laboratory research experience at their schools.

The program initially included only Sewanee students because of Mayes’ early ties to the university. But over the last 15 years, the number of summer interns has expanded from one to 15, and the intern population has expanded to include students from Yale, DePauw University, Kenyon College, Temple University and Bard College — though Sewanee students still constituted the majority of the group, filling eight of the 15 spots, Sholtz said.

“I knew from experience how much summer internships can help,” Mayes said. “If you’re from a small liberal arts college and you’re thinking about medical school, you need some experience to know what it is like.”

But structural changes were made to the program this year to extend the research experience into the academic year.

Though the summer internship allows students to acquaint themselves with virtually any field of research the Child Study Center offers, two previous participants of the summer program said a semester to train and research with professors and research assistants would have further enriched their learning.

“Over the summer Dr. Mayes was trying to get us to experience all that the lab offers,” Eliza Sholtz, a 2010 intern and Sewanee graduate, said. “More time in here would add to the experience.”

The relaunched program allows the select two or three students accepted into the program each year to choose the semester and the research area that will work in during their time in New Haven. Students who want to research at the Child Study Center but are unsuccessful in their applications to the semester program, can still apply to the original summer internship — without the semester of study.

“We want to start small,” Mayes said. “If it works well we can expand, but the first year we hope to get two or three students closely supervised research experience.”

Those students, Mayes said, could come from anywhere.

During the summer Sholtz said she researched adolescent traffic safety with Professor of Emergency Medicine Federico Vaca. She now works as a postgraduate research assistant at the Child Study Center and will continue her research with Vaca until she begins medical school next year.

Sholtz said four previous Child Study Center interns now work at the Study Center as research assistants to gain more “hands-on” research experience before medical school.

Research assistant Ann Thomasson said her “invaluable” experience at the Child Study Center during the past two summers provided an easy transition to working at the center fulltime.

Applications for the 2011 spring and summer research program are due Nov. 1.