PAINTINGS AND WORKS ON PAPER BY JUDITH ELLEN SANDERS at the UMass Medical Center Gallery, 55 Lake Avenue North, through September 29. Viewing Judith Sanders's paintings is like revisiting that Oscar- winning sci-fi picture "Fantastic Voyage," in which a medical team is reduced to microscopic size and injected into a human body. No, the walls are not covered with pictures of Stephen Boyd and Raquel Welch, but each painting does owe a strong allegiance to the microbes, erythrocytes, ganglia, and other biological formations that played a major role in the movie.

The natural marvels of biology are, in fact, the basis of Sanders's works. While a master's student in science at UMass Amherst, she enrolled in drawing and painting classes chiefly to amuse herself and keep academic pressure at bay. When she began to witness some of the biochemical changes that continuously occur within the body, Sanders says, she "was so overwhelmed by what goes on in a reaction, like when glucose changes to energy. It was so beautiful to see the transformation, one molecule at a time moving on. It just changed my art. I graduated from school, and the next day I started painting -- never looked for a job."

Prior to the revelation, Sanders's painting was hard-edge and geometric, similar in intent to works by Frank Stella or Richard Anuszkiewicz, relying on straight lines and color patterns for her formal structures. Sanders still retains a hard-edge approach to her work, but these lines now curve and whirl all over her canvas, and her rich color palette knows no bounds. She rarely uses preparatory sketches, preferring to lay thin strips of tape directly on a gessoed canvas. Much like nature itself, her work continually changes as a pattern begins to emerge; it sometimes takes several months to complete a single image.

An excellent example of this time-consuming technique is Early Journey. We are presented with a rush of brightly colored, wave-like elements that streak across the black canvas. Like a herring run or a startled flock of birds, these sharply defined components take off in individual, but internally ordered, flight. Although she imagined that this particular image depicted the act of conception inside the human body, she likes to leave the meaning of her work open to other possibilities.

It is the very concept of "possibilities" that drives Sanders's work, which depicts activities still underway, elements caught as they shift from one place to another. Nothing is presented as stationary. The goal or endpoint is not even in sight. In Sanders's six-and-a-half-foot horizontal canvas Flow, the gracefully undulating ribbons of color appear to be living roots that are just about to burst through the ground to start another stage of their continuing natural development. Or it could be an image of seaweed underwater. In either case, she is able to convey that the objects are in motion. Her adept combination of gyrating lines and vivid colors virtually force us to look at every part of the image repeatedly. In reality, the picture is not moving, you are.

Sanders further strengthens her portrayal of possibilities and continuation by wrapping her patterns around the curved edges of her canvas and leaving it all unframed, as if to imply that there is more -- that the painting itself is still evolving. In the five-foot-long painting Symphonia, small, well-ordered particles, similar in color and shape, appear to be making a covert escape from their repetitive squares, joining together to form a gigantic explosion of color that, in turn, pushes at the edge of its rectangular confinement in expectation of things to come.

Each of the dozen works on display effectively carries Sanders's underlying positive attitude, a sense of joy that hints at how much more there is to life than just mundane daily activities. "It's like the feeling you get when you're standing on top of a mountain with your arms stretched out," she says. And I can't think of a better venue to experience these uplifting paintings than in the lobby of a medical building.