The words come like Morse code from the consciousness; like notes on a conversation, terse messages from behind the eyes. Aphasia is the medical name for it, the lingering legacy of a stroke that actor/director Joseph Chaikin suffered in May 1984. What is noteworthy here is that Chaikin, 50, whose career in experimental theater has already been extraordinary, has in less than two years relearned language to the extent that he is going to perform in public.

This week Chaikin will open a two-week run in "Is This Real?," part of a double bill that inaugurates the American National Theater's fall season and christens its use of the New Playwrights' Theatre as a small, community-based outpost. The second piece on the double bill is "Solo Voyages," which Chaikin directed. It will be his first public appearance since his illness, aside from a reading at a benefit in New York for a rehabilitation center for stroke victims.

Chaikin has never performed in Washington; he was here once as a teen-age tourist, and once for a protest march in the '60s. While he is not well known to the general public, his reputation among theater cognoscenti is secure. As part of the experimental, avant-garde theater movement that began in the '50s, he came into full voice in the '60s, metamorphosed in the '70s and is heaven-knows-what in the '80s, Chaikin has earned a place as an innovative and creative voice.

"Through his investigations in the Open Theater and after, Chaikin has probably done more than anyone to shake American theater loose from its 19th-century roots in naturalism and psychology," writes Eileen Blumenthal in a new "work portrait" of him published by Cambridge University Press as part of its "Directors in Perspective" series. "He has found new ways to develop non-literary languages and non-narrative structures for the stage and, in the shadow of films and television, to affirm the special energy of its liveness. His example, moreover, has inspired the growth of experimental workshops and ensemble creations, and has nourished resistance to commercialism. Although he has kept out of the limelight, most theater in America and much abroad have been touched by his innovations in stage aesthetics, values and training."

If that all sounds a bit high-flown, if not obscure, some of Chaikin's work has, indeed, not been particularly accessible. His "pieces" are not traditional plays. They may be a series of images rather than a story, or may use words as sounds rather than as a literal expression. Experimental theater questioned all assumptions, from the location of the audience to the price of tickets, from the definition of a play to the role of the actor. Commercial theater was considered anathema; most plays deemed artificial, phony, irrelevant and unrepresentative of the human condition. Experimental theater has reflected and in some instances been a part of the political upheavals of the times.

The Open Theater, for example, in its early years did not always have public performances as a goal, and in its 10 years produced only two productions commercially: "Viet Rock" and "America Hurrah." Exploratory workshops (which today have been used to produce Broadway hits like "A Chorus Line") were the work of the company; there was more likely to be a "meeting" than a "rehearsal." Using improvisations, the actors created a "piece" rather than a play, sometimes refined and organized by a playwright.

Chaikin's interpretations of Samuel Beckett's work ("Endgame," "Stories and Texts for Nothing," "Waiting for Godot") are considered seminal, and his collaborations with playwright Sam Shepard have produced arresting work ("Savage/Love" and "Tongues," among others).

Some of Chaikin's pieces have been advertised solely by word of mouth, but the tom-toms of the New York theater community usually produced good houses. He was in one movie, "Me and My Brother," (1968) directed by Robert Frank, in which he played a schizophrenic who had withdrawn from "the coherent world."

Much of his work has been to explore, as Blumenthal put it, "ways to transmit conditions that have no adequate expression in life or art: feelings too extreme or elusive to have a vocabulary, too complex or subversive to have a forum."

Rather than a story expressed in dialogue, for example, a piece might present ideas through metaphors. In one early Open Theater piece, "Contest," actors developed a laughing contest, supervised by a policeman character who would arbitrarily change the rules. In Blumenthal's book, Chaikin is quoted describing the piece as being about brainwashing "and the giving over of the human to being a contestant in a world which prescribes the rules which go counter to the human, but are nonetheless irresistible to everyone." In 1982, in "The Other," a work developed in Israel with both Arab and Jewish actors, he devised a suffering contest between Palestinians and Jews, complete with a blackboard and scorekeeper.

So there is a special, elusive and strange irony in the current situation. The man who has probed the farthest reaches of communication is now struggling to say sentences; the artist who has used sound as a paintbrush could at one point make only sounds himself. "Pooh, pooh, boo," he said, illustrating the only things he could say immediately after his stroke. "I can't talking nothing." Sometimes he can tell you what he wants to say only by throwing out clues, a sort of word charade that can be quite effective with the people who know him well.

"Is This Real?," which was recorded as a 20-minute radio play earlier this year, is about aphasia, using excerpts from poems by Muriel Rukeyser, Pablo Neruda, Gertrude Stein and others, and from the Chaikin-directed pieces "Mutation Show" and "Trespassing." Two other actors, Ronnie Gilbert (who also directed) and Harvey Perr, add narrative material and comments.

"Lightning struck at me from behind my eyes," Chaikin says near the beginning. "Between the lips and the voice something goes dying," he says at another point. A refrain:

Let us see

Is this real?

This life I am living?

As a child, Chaikin had rheumatic heart disease. He was kept in bed for a year and a half. At the age of 12 he was sent to a Florida charity clinic for children with heart problems, far from his family in Brooklyn. As an adult he has had three open-heart operations, the third followed by the stroke. He has been plagued by bad health throughout his life; in some ways he has felt better since his last heart operation (in which an animal valve was replaced by an artificial one) than ever before.

He was hospitalized for several months and for a time wore a brace on his right side. A former student from Sarah Lawrence who became a brain surgeon instead of an actress helped explain what had happened to his brain. "The mood part of the brain very big. Speech, tiny," he said. And did he find that encouraging?

"No," he said, shaking his head. "So slow, so slow."

Chaikin has curly gray hair and a gentle manner, with a slightly mischievous smile. He liked his surgeon, he said in response to a question, because he shared Chaikin's passion for classical music and because "he's fun, too."

"One of the hardest things to get past is the willingness of most stroke patients to give up," said Chaikin's friend and business manager Jane Yockel. "The simplest things -- not being able to ask for a glass of water -- bring on a kind of despair. They have to be pushed. In this case, the main pusher was Joe. Speech therapy is a deadly and wearying and repetitious thing to go through, and he was willing to go through it seven days a week if he could."

Friends rallied to support him in a variety of ways. As an artist who has always lived on the financial brink, and who has a mighty unconcern for things monetary, Chaikin could have faced disaster. Years ago producer Joseph Papp, who sheltered various Chaikin projects, put him on his New York Shakespeare Festival Public Theatre payroll so that he would be eligible for health insurance, but even that could not pay for the extra speech therapy or support him while he was unable to work.

So Papp and others, including Beckett, Arthur Miller, Susan Sontag and Stella Adler, signed a letter appealing for donations that would support him for two years. Nearly 200 people, giving anything from $5 to much more, contributed to a fund that is keeping him afloat. He seems to find the spirit of this generosity as warming as the cash.

Other friends stayed with him during the months when he could not manage on his own, helping him cope with basic chores. The stroke left him confused about numbers, "especially the money," so getting correct change was daunting.

After he leaves Washington, he will go to San Francisco to create "a vaudeville about crime," and in February he will return to Israel to direct a second production of "Imagining the Other," a collaboration between Arab and Jewish theater artists, which he did once before in 1982.

His main love, however, is classical music. All popular music is terrible, he said. His future theater pieces will always include music, he said, "not only talk, talk, talk."

It is odd that a man who has spent so much of his life investigating the nether reaches of the mind is, in a way, now living there. It will be interesting to see what he reports.