One winner felt instant relief, and another felt enough anxiety to go to a psychiatrist.

A third began receiving phone calls from Rolls-Royce salesmen and got a gold credit card in his morning mail.

It's been nearly 3 1/2 years since 21 people picked up the telephone and learned they had won up to $300,000 -- tax free.

The money came from a new, then-unknown foundation named after the Chicago insurance billionaire John D. MacArthur and his wife, Catherine. The idea was to seek out "exceptionally talented individuals" and give them a substantial chunk of money on which they could float their "intellectual freedom." The basic grant was $24,000 annually for five years, with older recipients receiving larger stipends.

Like the 120 MacArthur fellows named since in five additional announcements -- the most recent ones yesterday -- none of the original winners applied for the grant. All were chosen by 100 anonymous educators, scientists and artists and given one instruction: Do whatever you want with the money.

The prize winners have ranged in age from 21 to 78; in vocation from paleontologist to poet. A few referred to themselves as different from the rest, using terms such as "oddball," "loner" or "wanderer." Others feel a part of the crowd, like Princeton Islamic-history professor Roy Mottahedeh, who said that prize or no prize, "I am just an ordinary bread-and-butter professor."

To Pulitzer Prize-winning author and child psychiatrist Robert Coles, 54, the MacArthur came "like a good swift current to carry me along just when I was getting tired of swimming"; yet to Steven Wolfram, a physicist who won the prize when he was 21, "It just wasn't a tremendous event in my life." For the oldest and perhaps most famous original MacArthur Foundation fellow, novelist-poet Robert Penn Warren, now 79, "No amount of money can take the place of the discipline to make time."

Despite the differences, many share common ground.

They are mavericks, innovators bursting out of conventional single disciplines. And when many of the original MacArthur fellows spoke separately about the unprecedented prize -- one that has been called everything from the "American Nobel" to a real-life version of the old television series "The Millionaire" -- most agreed that it accomplished what it apparently set out to: free them from salaried positions. But they also speak of the less happy side of a "no-strings-attached" grant. A little reluctantly, they talk about the pressure of living up to a "genius award," of the jealousy of colleagues who wonder, "Why you and not me?"

And they ask, "What next?" The Gift of Time

"I no longer have to justify myself before fools," says Michael Ghiselin, 45, a research biologist and science historian who quit his tenured position at Berkeley after he won the MacArthur.

Ghiselin, now associated with the California Academy of Sciences, a museum in San Francisco, continues the research he is most noted for -- the evolution of animals -- while he writes a book on bioeconomics, an explanation of how scientists do their work, using economic terms.

"I am not going to have a real job for the rest of my life," says Ghiselin, who reinvested much of the $216,000 from the MacArthur Foundation in real estate so he would "no longer have to spend time coping with the cutthroat politics at the intolerably stifling university communities."

Ghiselin divides his financially worry-free life between his work space in the San Francisco museum (for which the MacArthur Foundation pays an additional $15,000 a year) and his new home overlooking the Russian River west of Santa Rosa. He rises at 5 a.m. and works till "the cocktail hour" on his two main projects but also dabbles in literary criticism, psychology and philosophy.

"I can do as I please now without having to answer to anyone," says Ghiselin.

Cornell professor and poet A.R. Ammons has kept his ties with the university, but says his $256,000 award lightens his class load:

"It gives me twice as much time to try to write. But that doesn't mean I write twice as much," Ammons says. "It's too humiliating to sit down and bang my head at the typewriter and say, 'Think of something! Think of something!' " Instead, he uses the extra time to take long walks. The 55-year-old poet has published 18 books of poetry, two since receiving the MacArthur.

"I don't believe in anything extravagant," says Ammons. "I like where I am, and besides, I have seen enough of the world to know it's all much the same."

For biochemist Robert Root-Bernstein, 30, $144,000 meant he could drop the postdoctoral project that he was working on. "It was too restricting, too boring," he recalls.

What he really wanted to do was study scientific creativity, an unorthodox analysis of how people invent theories. But because such research seemed to fall between disciplines, he thought he could never get institutional support.

Then the MacArthur call came.

"The funny thing is," he says, "when I was in graduate school at Princeton, I remember sitting in a lounge and saying, 'what's missing in life is a Renaissance patron.' One of my friends was reading an article on the MacArthur Foundation and said 'Hey look, they are forming a club for geniuses.' " The Pressure of Success

One day John Imbrie was sitting at his desk. He realized that he had been handed more than $264,000 and a "gift of time," and increasingly he felt a "moral obligation" to do something nobody else could.

He says, "You feel like you are an Olympian and you have got to do your damnedest to win the gold."

Imbrie, a Brown University oceanography professor studying long-term climate forecasting, hopes to raise the accuracy rate as high as 80 percent. Currently, he says, it is not much better than 50 percent.

He works 12 hours a day, and still, he says, even when he is lying in bed he thinks about the data he collects from century-old ship readings and experts from around the world. "You know," he adds, "my wife thinks I am getting absent-minded, but I hope to have made a major contribution at the end of this five years."

Pressure itself is not new to the winners. They all seem driven to write, to invent, to perform. But now, many say, they have to answer not only to themselves but also to the public, which may expect a return on the MacArthur "investment."

Mathematician and psychologist Charles Garfield is not surprised that MacArthur fellows speak of their awards as a grant of time rather than money. "The greatest single obstacle to excellence is poor time management," says Garfield, the author of "Peak Performance," the result of his 18-year study of extraordinary performers in a wide variety of fields.

Garfield says that along with the constant pressure of time constraints, peak achievers feel a "high-intensity" pressure to produce. "It takes quite an accomplishment to give them peace of mind," he says.

The pressure is felt by those at the height of their profession as well as by those with promising beginnings. New York research psychologist and consultant Marilyn Machlowitz, who once asked the MacArthur Foundation if she could study the original award winners but was turned down, compares the prize to the Nobel and a lottery. "The Nobel is a well-established prize clearly given out for past achievement, and you know who picked you . . . The lottery has the advantage of randomness." But the MacArthur awards have no history and are undefined and mysterious, says Machlowitz, leaving the winners "with an uneasy sense of being watched."

Michael Ghiselin found after winning the award that he couldn't sleep because he was constantly thinking of new ways his work on evolution might be applied. "Nobody tells you anything," he says. "At first I got so upset with the novelty that I needed psychiatric help."

To literary critic and Yale professor Henry Louis Gates, Jr., the award came as "instant responsibility." Gates, an associate professor of English and Afro-American studies, says, "I still don't know much about the program but when I discovered the earliest known novel published by a black person in the U.S. ("Our Nig" by Harriet Wilson, 1859), I thought, 'Ah, this is the sort of thing MacArthurs are supposed to do.' "

Gates, 33, says when he was awarded the prize "implicit pressure" passed into his hands.

"But I've been lucky. I got a boost of energy from winning that has helped me ride out the pressure."

One of the three women among the first group of MacArthurs, Leslie Silko, 36, all of a sudden feels time running out.

"I haven't saved a dime," says Silko, a novelist, filmmaker and poet who won $33,600 for each of five years. "I quit teaching immediately to write my novel and if it's not finished when the checks stop coming . . . well, it has to be."

Silko, a Pueblo Indian raised on a New Mexico reservation, lives with the older of her two children in what she calls a "broken-down ranch" in the hills outside Tucson, Ariz. There she continues her sole pursuit for the past three years: a 1,200-page novel about the American Indian set in the contemporary Southwest.

After Silko's call from the MacArthur Foundation came, she said she was "besieged with hassles." She was going through a divorce, in which "the judge held against me everything the MacArthur awarded me for." The custody of her 12-year-old went to her ex-husband because, according to Silko, "I was making films and writing and wasn't busy being a traditional mother." The Jealousy Factor

The awardees must also confront the jealousy of others. Ralph Hupka, a California State University at Long Beach psychologist who specializes in research on jealousy, says that envy over another's success is "inevitable in our competitive society. We always hold number one up high and if he happens to be your colleague, you might feel like you have failed or they have received unfair recognition and rewards."

Hupka says that jealousy is powerful enough to harm careers, but many successful people learn to deflect it. For instance, he says, "They might say they were just lucky, so that others might feel they have a chance too."

Leslie Silko describes the jealousy this way: "Some people just say, 'At least I am glad that a writer got it,' but others come right out and say, 'So, I heard you got some big, fancy award.' " Adds Silko, "You can just imagine the tone."

University of California anthropology professor Shelley Errington, 39, recalls a Buddhist adage that a friend told her after she'd won the MacArthur: "The dangers of great, good fortunes are exactly proportional to the goodness and greatness of the fortune." She says it as though she believes it.

Just having finished a novel set in an ancient Indonesian kingdom, Errington, who is a specialist in Southeast Asian culture, plans to begin teaching her "latest thing" -- cultural perspectives on the body. For instance, she says, "Western medicine won't practice acupuncture and our magazines present different images of the ideal body."

"For one year, all the fireworks were going off," says historian Carl Schorske, 69, who finished a book, retired from teaching and won a Pulitzer and $300,000 from the MacArthur Foundation seemingly all at once. "It was crazy, uncontrollable; everything was coming out of the sky." After the sky cleared, however, Schorske noticed a "definite cool reaction" from those in his field as well as the public.

"Nobody said, 'What the hell did they pick a jerk like that for?' but I felt the coolness."

Schorske noted that the reaction to his Pulitzer for his nonfiction book, "Fin-de-Siecle Vienna," was "100 percent uniformly generous." The MacArthur, however, caused problems. "There is always envy in close fields," says Schorske, "and the MacArthur just opened it up."

Steven Wolfram wasn't excited about the prize in the first place. "Let's just say the MacArthur did not help me make friends," says Wolfram, 24, the youngest of the original MacArthur fellows.

He says he now works increasingly on his own, since his colleagues at the California Institute of Technology in Pasadena, where he was a research physicist, "especially those who were not terribly successful," caused "a lot of nonsense for him" after he won the award.

Harvard professor Sheldon Glashow, a 1979 Nobel prize winner in physics, says that when he won his award his colleagues "were all smiles." But he does not think you can compare the two awards.

"It the MacArthur comes too early to be a goal that you've spent your life working toward," the 51-year-old physicist says. "It's more of a push along the way." What's Next?

All the MacArthur awardees feel the push, but many also ask, "What do you do after a MacArthur?"

"I could have put the money in the bank and taken a job," says Root-Bernstein, the father of two children under 2, "but I took the higher risk because I think the MacArthur wants people to delve into the unorthodox."

He thinks that when the award checks stop coming he will have trouble finding employment. "It surprised me at first that I got no offers, but then I realized that the publicity I was getting was outside academics." He says that the mainstream academics who do the hiring look on the MacArthur winners as a "bunch of crazy people."

There is little reward, he says, for innovation; two Renaissance patrons in one lifetime seem unlikely. Yet he plans to continue his research. "I still wonder if I am doing the right thing, but I keep thinking I would never have gotten this in the first place if I played it safe."

"You know," Root-Bernstein adds, laughing, "I think they ought to do a study on what happens to people who win the awards after the money stops coming. They are more addictive than heroin. I guess I'll have to go cold turkey and sit and shiver it out."