It was her first day on a new job. Diane Kullen, 38, was standing in the office with the doctor who had hired her to sort out his mailing lists. The doctor was telling her about the gleaming new machine in the next room, the word processor Kullen would be using. He was saying what an efficient machine it was, how it could easily merge address lists with letters, alphabetize them and sort the whole bunch out by ZIP code.

Suddenly, she panicked.

Her heart was racing and sweat began forming on her palms. It was like the time a few years back when she had been riding the Dupont Circle Metro station escalator, looking down into the tunnel. The panic she felt that day had shaken her so badly that it was months before she could ride another escalator. Even then, she had to ride with friends for a while, rebuilding her confidence.

She had gotten over all that -- until she met the computer.

"I will not go near that thing," she is saying a few days later in the relative safety of her Bethesda living room. "I'm glad it's in a separate office. If it's going to be moved into mine, I may have to move out . . . Every day I walk in there I'm praying, 'I hope it's not today that I have to work this word processor.'

"I may look back someday and laugh at this. But right now I don't think it's funny."

Kullen assumes that her fear of computers is "very strange." But evidence gathered recently by a team of business professors at George Mason University suggests that, far from being alone, she may be part of a sizable new category of American phobics -- "cyberphobes."

Working with a psychologist who specializes in phobias, the professors surveyed 462 managers and professionals in the Washington area about their attitudes toward computers. Eleven percent of the managers surveyed were classified as "computer anxious" -- they avoid computers when possible, but probably would be cured of their anxiety after taking a computer training course.

Another 3 percent of the respondents, however, were found to be genuinely "cyberphobic." In the presence of a computer, these people suffer from feelings of panic and terror, heart palpitations, breathing difficulties, dizziness, trembling and feelings of going crazy or losing control.

"Most of us sit down at a computer and there is a risk that we'll make a fool of ourselves," says Jerilyn Ross, the psychologist who worked on the study. "But the phobic is afraid that they'll become so overwhelmed with anxiety that they'll pass out or they'll go crazy, or that they'll lose control and harm the machine."

So it was for Sue Kent, a secretary in Palo Alto, Calif. Kent felt she needed to learn about computers to advance her career but was so afraid of the machines that "if I just looked at them, I would be sick." Working with a psychiatrist in Silicon Valley, Kent set incremental goals for herself to overcome her fears. She began by looking at pictures of a computer, but "my anxiety was such that I couldn't see it. It was just a blur of anxiety."

Eventually, she pushed herself to walk by a store that had computers in the window, and later she went inside and sat down before a terminal. She felt so bad that she got up and rushed outside.

After months of therapy, Kent finally felt comfortable enough to buy a Commodore home computer. "Now," she says, "I'm at the point where if the computer makes a mistake, I say, 'You dumb machine.' I love it."

Arthur Hardy, Kent's psychiatrist, says that he has seen a number of cases of cyberphobia among the ambitious entrepreneurs who have made Silicon Valley into the American capital of high technology. "It's something that they're ashamed of, particularly men," he says.

Hardy recounts the case of one high-ranking computer executive who was so afraid of the product his company sold that his career was in jeopardy. Hardy encouraged the man to share his fear with his immediate superior, the president of the company.

"He got his nerve up and told his boss," Hardy says. "And his boss said, 'You too?' "

Phobia specialists say that it is not unusual for a pervasive new technology to provoke phobic reactions in a large number of people. Part of the reason, they say, is that excitement and fear are closely related emotions: The same stimulating qualities that make some people go gaga over computers send others into a state of paralyzing fear.

"That's true of all technology," says Robert DuPont, director of the Washington Center for Behavioral Medicine. "If you look at the introduction of railroads, automobiles, air travel, escalators, elevators -- all the ways in which technology touches people's lives have been associated both with transient anxiety-fear reactions, and with real phobic reactions. What happens in the population is that as the technology becomes more widely experienced, the fears tend to go away and one is left with a residual phobic category."

In the cases of cyberphobia and aerophobia (fear of flying), these "residual phobias" not only disrupt the lives of people like Diane Kullen and Sue Kent, they also have a profound impact on business and the economy. DuPont estimates that 25 million Americans are afraid to fly, and he says many of those will avoid air travel even if it means turning down a job or a promotion.

Similarly, says Stephen R. Ruth, one of the George Mason University business professors who worked on the Washington-area computer survey, the implications of cyberphobia "can definitely be expressed in dollars . . . Unless more organizations become aware of the costs associated with possible phobic responses to massive introduction of computer systems, the potential loss of productivity may increase dramatically."

But the actual experience of cyberphobia, at least as it is described by its victims, has little to do with the economic and sociological aspects of computer use, or with Orwellian paranoia about the threat of new technology. The George Mason study, for example, reported that cyberphobics are actually less afraid than others that computers may someday replace them on the job.

Instead, the phobia is an intensely personal experience, a waking confrontation with nightmarish demons. Trying to describe what she feels in the presence of a glowing computer screen, Diane Kullen says, "I mean, I look at this thing, and it's like . . ."

She stops and shudders violently. After a pause, she says, "Right now, even talking about it, I'm feeling a little fearful."