In Little Rock, Ark., a 39-year-old American convert to a far eastern religion allows the underside of her forearm to be injected with chicken pox virus. Her cooperation is part of an unusual nine-week experiment designed to test whether thought and emotions can alter the immune response.

The woman has been chosen for study by a team of psychiatrists and immunologists at the University of Arkansas for Medical Sciences. She is a dedicated meditator with nine years of daily experience, and they believe she is especially attuned to her body's responses.

Within 48 hours of the first injection, a bump about the size of a nickel appears on the woman's arm, then slowly disappears during the next four to five days. This is a normal, positive immune reaction and indicates that she has been exposed previously to the virus. Blood samples confirm the skin test: When the woman's white blood cells confront the virus, they become larger and gear up to fight the invader by producing greater amounts of protein.

She receives two more injections, and the reaction each week is the same.

Then the researchers ask her to try to change her body's response: Can she stop her white blood cells from reacting to the virus? During part of her daily meditation, the woman visualizes the injection site and sees it growing smaller. For three consecutive weeks, the weekly injection produces a significantly smaller bump. Blood tests also show an altered response. Far fewer white blood cells prepare to fight the infection.

Finally, the researchers ask the woman to stop trying to control her immune response and let it return to normal. For the last three weeks of the experiment, the nickel-size bump reappears after each injection and the blood test again reflects a positive immune reaction.

"We were so startled by the results that we decided to repeat the experiment nine months later," reported Dr. G. Richard Smith at the recent International Conference on Neuroimmunomodulation. "We found the same results."