Physical and psychological torture for political purposes has reached "epidemic proportions," an American medical representative for the human rights organization Amnesty International reports.

Dr. Michael Nelson said concerned physicians and their colleagues around the world are documenting an increased frequency of "savage barbarity" in more than 30 countries.

Although information is difficult to obtain, more than 60 torture victims who have survived and reached the United States have been examined and helped by Amnesty International medical groups within the past two years, Nelson said.

Their findings and the experience of a torture victim were presented at the American Association for the Advancement of Science meeting here, which sought to update the scientific community on the problem.

Viki Zunzunegui, a research statistician and graduate student at the University of California at Berkeley, has begun to computerize data gathered from 46 of the Spanish-speaking victims, many of whom came from Chile, Argentina, Uruguay, Brazil, and most recently, El Salvador, Guatemala and Colombia.

In her paper, she said that patterns of beatings following arrests were similiar with all of the victims--36 men and six women in their late 20s and early 30s--she studied. Torture by electricity was found in 75 percent of the cases, stretching in 40 percent, submersion in 14 percent and burning in 13 percent.

She said that 7 percent were sexually abused; only a small number were subjected to drugs.

Psychological torture included threats of deaths and denial of privacy, blindfolding, and isolation after torture.

Years after their releases, many torture victims suffered from headaches, back pain, hearing loss, anxiety, difficulties in memory and sleep disturbances.

Zunzunegui said the group she is studying is not representative, since they are survivors who tended to be in better physical condition than other victims.

Torture, she said, is something that "nobody wants to talk about it. It's horrible to think about. The result is that little is being done to solve the problem and there is little information on the best way to help victims."

Carlos Sanabria, an Argentinian who participated in the study, told of his experiences after being arrested in 1977, during what he called the "worst, bloodiest period of the whole history of my country."

During three months in a concentration camp, he said he was "tied, blindfolded, and not allowed to talk with other prisoners," while always "waiting for another session of torture." He said he was subjected to electroshock and other forms of physical and mental abuse.

Sanabria described himself as a political activist advocating democracy who "never used violence to further my political beliefs." He came to Seattle in 1979 and, after a period of adjustment, has been working to alert others to problems in his country.

In addition to some South American countries, Nelson said that torture is alleged to have occurred on a "significant scale" in Africa, Asia, Western Europe, Eastern Europe, the Soviet Union, Middle East and North America.