In 1961 and 1962, a Medical School assistant professor and a Harvard researcher gave large doses of radioactive iodine to "mentally defective" children ages one to 11 in an attempt to determine the consequences of nuclear fallout.

The children in the experiment attended the Wrentham State School for the retarded, which is administered by the Massachusetts Department of Mental Retardation.

The experiment was brought to light by a Medical School professor who came across a published study of the experiment last week while preparing for a lecture, Vice President for Government, Community and Public Affairs Jane H. Corlette said last night. The study was mentioned in a footnote the professor saw, she said.

The experiment, made public yesterday by the state and by Harvard, links at least two more University scientists to government-sanctioned tests with radiation conducted on retarded children.

A late Harvard professor, Dr. Clemens E. Benda, performed tests with radiation at the Fernald State School in Waltham.

Benda's experiments involved using radioactive tracers in milk as a way of monitoring the calcium uptake of the retarded students. While ethicists have objected to the Benda tests because students were not notified of the radiation used, medical experts say the amount of radiation did not pose a health threat.

A Harvard task force is examining the University's involvement in Cold War era radiation experiments, including those at Fernald and at Wrentham. Harvard turned the Wrentham study over to the mental retardation department along with a series of other documents on Friday.

A department task force, which is also investigating the Fernald experiments, interrupted its ongoing probe yesterday to issue an angry press release condemning the experiment.

"For government researchers concerned about radioactive fallout to use institutionalized two-year-old children is an insult to the children, their families and to every individual concerned with individual rights and dignity," Frederick Misilo Jr., chair of the task force and the department's deputy commissioner, said in a prepared statement.

"I am deeply troubled by these revelations," Misilo said.

This most recent experiment was performed over a four-month period in 1961 and 1962 at the state school in Wrentham, a suburb located an hour's drive south of Boston.

The study, sponsored by the U.S. government's Public Health Service Division of Radiological Health, was published in Science magazine in October 1962, the same month as the Cuban missile crisis.

Harvard, in response to the state task force's condemnations, issued its own statement yesterday.

"There are serious and troubling questions about why children at an institution such as the Wrentham School werechosen to participate in this research," thestatement said.

"We are committed to exploring these questionsnot only through continued cooperation with the[Department of Mental Retardation] task force, butalso through a special Harvard faculty committeethat has been formed to review research involvinghuman subjects in decades past."

The state has set up an 800 telephone line forformer Wrentham School residents and theirfamilies to call if they have questions of believethey may have been involved in the experiments.The number is 1 800 377-9237.