LONDON, NOV. 8 -- U.S. researchers say studies of 58 people who were near death or who thought they were dying support theories that a feeling of well-being and clarity of mind precedes death.

The researchers from the University of Virginia, writing in The Lancet, a British medical journal, said they drew their data from the medical records of 28 patients judged to have been so close to death they would have died without medical help.

They also looked at the records of 30 patients who were not in danger of dying but thought they were.

"Patients of both groups reported closely similar experiences but patients who were really close to death were more likely than those who were not to report an enhanced perception of light and enhanced cognitive powers," they said.

The researchers said the three major theories associated with near-death experiences since the time of Plato -- the transcendental, the physiological and the psychological -- were based on the premise that patients were near death at the time.

The fact that the two groups monitored in the new study shared similar experiences such as perceiving a strong light, sometimes seen at the end of a tunnel, and the belief of having left the body and floating above it, strengthened a case that psychological factors play a part, they said.

"The results we obtained, far from refuting any of the three principal interpretations of {near-death experiences}, offer in different ways some support for each of them," the group said.

"The psychological interpretation receives support from the evidence that persons who are not near death. . . may have experiences that in all respects resemble those of persons who are near death," they added.

The report concluded that the data showed that patients near death could experience a clarity of mind even as brain function diminished.