"Dare 2 Re-flect," exhorts one of Susan Firestone's flashing neon and plexiglas sign/sculptures at Gallery K. "Power. No power. Empower," mulls another of her electronically timed sequences that toy with loaded word variations.

Firestone has been toying with words since her childhood in rural South Carolina, when she began filling diaries with ideas and images that eventually began to merge and evolve into a personal, pictographic alphabet. A painter and collagist, she has explored several other media over the past few years, always in search of better ways to convey complex thoughts through pared-down, pictorial means. None has been so successful as the neon work in this show.

Along with several better-known women artists -- Jenny Holzer and Barbara Kruger chief among them -- Firestone has found a way to be heard over the din of contemporary society by appropriating media better known to Times Square than to the art world, including moving signs and billboard-size posters. But instead of selling cameras and blowing smoke, these "signs" are aimed at prodding thought about the realities of our life and times, and -- in the end -- the plight of contemporary civilization.

Passive acceptance of the status quo seems to be what currently concerns Firestone most, and the need to think and to challenge is most explicit in "Dare 2 Re-flect," a striking piece at the top of the stairs that flashes out a succession of energy-giving messages, underscored by images of a light bulb.

There are several other signs, like the emblematic "Rebel" and "Power," which seem somewhat awkward and trite. Most compelling, however, is "Compromise," a narrow sign that delivers a message of real power: "Don't compromise. Promise. Promise. Promise!" The impact is reinforced subliminally by the use of red neon to signify urgency in the word "promise," and yellow to suggest cowardliness in the word "compromise."

While these fabricated neon pieces are distinctly public in intent, there are also some quieter, more personal graphite rubbings that should not be missed. Combining objects (like saw blades and glove forms) with letters of the alphabet, they best convey the intensity of the artist's hand at work, and the automatic, instinctive and highly poetic way in which she proceeds. This varied, ambitious show also includes well-crafted, experimental silkscreen prints and an elaborate, 3-D construction based on the nude figure of Venus in the Corcoran.

The increasingly effective use of media-as-medium in art has been growing of late, and was first seriously examined by Hirshhorn curator Ned Rifkin in "Signs," a show he organized for the New Museum in New York in 1985. Firestone's challenge will be to continue to carve from this medium a distinctive statement of her own. She is well on her way in this show, which continues at Gallery K, 2010 R St. NW, through January.

Jonathan Shahn at Addison/Ripley

While some artists seek out new media, others prefer to explore new possibilities within the old. Figurative bronze sculptor Jonathan Shahn, now at Addison/Ripley Gallery, is one of the best and most inventive artists now breathing new life into a traditional mode.

He is also an artist in love with process, and that passion is what transforms his art. His "Portrait of A," for example -- the only bronze in the show -- typically incorporates into the casting the wooden armature upon which the head was fashioned, setting up a dynamic duality between person and portrait, between flesh and bronze. He carries this further in plasters for two portraits in which his sitters lean forward, resting their arms on the very slabs that also serve as their pedestals, again blurring the line between reality and his fabrication.

There is a wonderful clay wall relief here, the rough edges of which obviously gave the artist great sensuous pleasure -- a feeling he somehow transmits. But the centerpiece of this show (at least for those already familiar with Shahn's bronzes and plasters) is a new suite of roughly carved and joined wooden figures, among them some oversize heads lying sideways on pedestals and a full-scale female nude with outstretched arm.

Created out of his head (rather than from a specific sitter), they look somewhat tragic and bloodied at first, touched as they are here and there with areas of red chalk. The chalk, however, turns out to be residue from surface markings made by the artist to guide him in the process of cutting away certain areas. In the end, they inspired him to enhance the surfaces with more markings in black and white paint -- something he had no intention of doing until this accident of process began to propel him along. Though these works are impressive, and effectively underscore the pervasiveness of his approach, they resound with too many echoes from other contemporaries to be seen as much more than Shahn himself in the process of moving on.

His show, which also includes charcoal drawings, will continue through Feb. 12 at 9 Hillyer Ct., behind the Phillips.

Elizabeth Falk at Gallery K

Washington bronze sculptor Elizabeth Falk is best known for her table-top narratives dealing with themes of urban isolation, and that continues to be her strong suit. There are, among her new bronzes at Gallery K, several works that attempt to introduce figures in motion -- the best of them a man dashing down a spiral staircase. But they are, overall, unaffecting and sometimes awkward. Elsewhere, several shrouded figures titled "Shamen" hang around like film extras waiting for instructions. Most end up playing harbingers of death in unlikely places like school playgrounds. If they have a point, it is not made.

It is on the subject of communication -- and the obstacles to communication -- that Falk continues to excel, especially in "The Room," in which a young man and woman face and touch each other. "The Visitor" is an even more powerful expression of obstacles overcome, as a man and woman manage to touch and communicate fully despite the steel door that stands between them.

Falk's show continues at Gallery K, 2010 R St. NW, through January.