IOWA CITY, Aug. 5 (AP) - For six months, Mary Nixon and 10 other orphans were relentlessly belittled for every little imperfection in their speech

IOWA CITY, Aug. 5 (AP) - For six months, Mary Nixon and 10 other orphans were relentlessly belittled for every little imperfection in their speech to test the theory that children become stutterers because of psychological pressure. Sixty-four years later, the experience still stings. Ms. Nixon, now 76, and other test subjects sued the University of Iowa earlier this year over lifelong psychological problems they say stem in part from the 1939 experiment. The case has not only thrown a spotlight on an experiment some participants bitterly call the Monster Study, it has also illustrated the way research ethics have evolved over the years. "I don't think anybody today likes the idea of seeing orphans, children, used that way," said Jane Fraser, president of the Stuttering Foundation in Memphis. "But it's really important to keep things in historical perspective." The experiment was overseen by Wendell Johnson, a University of Iowa speech expert who set out to unravel the mystery of stuttering by trying to induce the disorder in orphans. At the time, he believed stuttering was learned behavior attributable to external forces, like criticism from parents for the slightest speech imperfections. None of the test subjects became stutterers. The suit, brought on behalf of three test subjects and the estates of three others, seeks unspecified damages. The university issued an apology after the study was made public in news reports three years ago. But the state also asked a judge last month to dismiss the case, claiming that the state is immune from such lawsuits under 1939 law. In recent years, other studies have come to light that used unwitting subjects to test such things as radiation exposure or the progression of disease. From 1932 to 1972, the federal government used poor blacks in Tuskegee, Ala., to see what would happen to men when their syphilis was left untreated. Congress passed rules in 1974 requiring informed consent for subjects of government-financed medical studies. Professor Johnson, who grew up a stutterer, was an expert in speech disorders when the field was in its infancy. He held a doctorate in psychology and speech pathology and was director of the university's speech clinic from 1943 to 1955. He died in 1965. Stuttering afflicts one in 100 people, and modern theories say it is has a mix of neurological and genetic causes. It typically appears in children between the ages of 2 and 5. The Iowa study, led in part by a graduate student, Mary Tudor Jacobs, involved 22 children, all of them considered normal speakers, from the Iowa Soldiers' Orphans' Home. One group received positive speech therapy; those in the other group were subjected to rapid-fire badgering and were repeatedly told that they were stutterers. Researchers concluded that those in the negative therapy group showed a loss of self-esteem and other detrimental effects. In court papers, lawyers say that Ms. Nixon, widowed and living as a recluse in a retirement home, spent her life believing that she had a speech problem and struggled with insecurities. The Iowa lawsuit accuses researchers and the university of hiding their findings, lying to the orphanage about the experiment and doing nothing to reverse the damage. Ms. Jacobs, who lives in California, has expressed deep regret about the experiment and said she returned to the orphanage three times in the 1940's to try to reverse any problems with the children.