Behind a well-kept lawn and plantings lies the enigmatic blank white face of the Transcendental Meditation Center.

Inside 33 Garden St., the atmosphere could not be less mysterious. There are no robed gurus here, but meditation teachers who wear jackets and ties. A full line of Maharshi Ayur-Ved products, from health-promoting teas to shampoo and massage oil, are for sale.

Transcendental meditation (TM) was founded in the United States in 1957 by Maharshi Mahesh Yogi. His foundation, the Maharshi Institute of Vedic Science, trains all TM instructors and governs the content and structure of TM centers. Local TM centers exist as franchises of the international corporation.

The introductory lecture for prospective students seems designed to put meditation in the context of normal life.

"It's not about 'lifestyle," says lecturer and teacher Patrick Pomfrey. "It's not a religion or a philosophy or a cult. What it is simply a mental technique."

The introductory film, which emphasizes the medical benefits of stress reduction through meditation, reinforces the success-oriented, mainstream atmosphere of the center. Three CEO's, a U.S. Navy lieutenant commander, Joe Namath and a Harvard doctor endorse TM in the film.

"We should look at TM like a procedure," says a white-coated doctor in the film, "a mental procedure like any other procedure we perform."

A grey-suited CEO proclaims, "TM is for dynamic individuals. It's for people who want to be successful, who get things done."

The benefits of TM, according to Pomfrey and to Beth F. Kupferman, the center's director, are stress reduction, better health, improved concentration, learning, attention and relationships.

And while the center was forthcoming about the benefits of TM, no one there would talk about what actually happens in their method of meditation. In an interview, all the director of the center would reveal is that the TM student receives a special mantra the first time he or she meets the teacher. The mantra remains the meditator's secret, as does the meditation process.

The course of instruction costs $1,000 for adults, $600 for students--perhaps one reason the TM corporation wishes to guard the secrecy of the process.

Still, one former TM practitioner was willing to talk about the process.

"I think it's a heavy component of hype," says Bruce C. Atwood, who began TM with his wife in the early 1960s.

According to Atwood, the mantra is not specifically tailored to the individual. There are only six mantras, which he hypothesizes correspond to three age groups and the two sexes. In other words, if Atwood is right, every young woman would get the same mantra.

The process of meditation, as Atwood related it, is simple. A person sits quietly and lets his or her mind wander. The person says the mantra whenever it enters the mind, and then lets the mind wander again, repeating the mantra whenever it naturally enters.