President Barack Obama Wednesday honored luminaries of the arts, including Star Wars creator George Lucas, praising his special effects for freeing movies from "planes in space" with visible strings.

Obama presented National Medals of Arts and National Humanities Medals to a group also including musician Herb Alpert, rhythm and blues legend Allen Toussaint, author Joan Didion and sportswriter Frank DeFord.

"The arts and the humanities aren't just a source of entertainment, they challenge us to think and to question and to discover, to seek that inward significance -- and that helps us grow and to change and to reach new heights," Obama said at a White House ceremony.

The president went off script when he came to pay tribute to Lucas, praising him for making "it look like those planes in space are actually flying."

"I remember when I first saw Star Wars -- there's a whole generation that thinks special effects always look like they do today," Obama said, prompting chuckles among audience members.

"But it used to be, you'd see, like, the string on the little model spaceships. Anyway, I'm being led astray."

Those receiving the Medal of Arts included Alpert, philanthropist Lin Arison, dancer Joan Myers Brown, singer Renee Fleming, author Ernest Gaines, painter Ellsworth Kelly, scriptwriter Tony Kushner, Lucas, comedian Elaine May, architect Laurie Olin, Toussaint and the Washington Performing Arts Society.

National Humanities Medal recipients were author Edward Ayers, economist William Bowen, historians Jill Ker Conway and Natalie Zemon Davis, Deford, Didion, political scientist Robert Putnam, writer Marilynne Robinson, poet Kay Ryan, book critic Robert Silvers, actress Anna Deavere Smith and writer-photographer Camilo José Vergara.