Twenty-two Americans ranging from a radio journalist to a sports trainer received no-strings-attached genius grants worth $500,000 each, a charitable foundation announced on Tuesday.

Since the program was begun in 1981, the John D. and Catherine T. MacArthur Foundation has provided grants to 850 fellows, with the aim of providing scientists, scholars, artists, activists and others the means and freedom to pursue their creativity wherever it leads.

Anonymous nominators and selection committees decide who gets the grants, and recipients usually do not know they are even being considered, the foundation said. The grant is made over a five-year period.

This has been a year of great change and extraordinary challenge, and we are once again reminded of the potential individuals have to make a difference in the world and shape our future, said foundation president Robert Gallucci.

Among the 22 winners, who ranged in age from a 29-year-old Seattle computer scientist to a 67-year-old silversmith, were:

* Jad Abumrad, 38, a musically-trained producer of Radiolab on WNYC radio in New York, who takes on a big idea for each program, using interviews, music and storytelling to bring the subject to life for listeners. The program often has a scientific bent. One past episode examined What is Time?

* Kevin Guskiewicz, 45, a sports trainer at the University of North Carolina, Chapel Hill, who has advanced the diagnosis, treatment and prevention of sports-related concussions. He helped recognize the impact of multiple concussions on professional football players, created a widely used on-field exam for head injuries and works with players in contact sports to change their approach to tackling and hitting.

* Poets Kay Ryan, 65, of Fairfax, California, and A.E. Stallings, 43, who lives in Athens, Greece.

* Historians Jacob Soll, 42, of Rutgers University in Camden, New Jersey, and Tiya Miles, 41, of the University of Michigan, Ann Arbor. Soll studies the origins of the modern state, and Miles the relationship between African and Cherokee peoples in colonial America.

* 29-year-old cellist Alisa Weilerstein, and Dafnis Prieto, a 37-year-old jazz percussionist, both from New York. Choral conductor Francisco Nunez, 46, who works with disadvantaged students in New York.

* Civil rights lawyer Marie-Therese Connolly, 54, of Washington, D.C., who combats elder abuse with a blend of legal, policy and legislative techniques.

* Architect Jeanne Gang, 47, who heads her own Chicago shop, Studio Gang, and is among the few women architects to design skyscrapers.

* Journalist Peter Hessler, 42, who has written extensively about reforms in China.

* Shwetak Patel, 29, a computer scientist at the University of Washington, Seattle, who has invented low-cost sensor systems for households to monitor energy usage.

* Silversmith Ubaldo Vitali, 67, of Maplewood, New Jersey, who restores silver pieces as well as creating his own original works of art.

Descriptions of the winners' work, along with brief videotaped interviews, is available on the MacArthur Fellows tab on the foundation's web site (www.macfound.org)