Olwen Fouere had not read James Joyce's epic novel, Finnegans Wake, before she adapted it for riverrun, her Dublin Theatre Festival hit which arrives at the Traverse Theatre for an Edinburgh Festival Fringe run next week.

But being from Ireland, the maverick actress and director had, of course, dipped into what is often regarded as an impenetrable text over the years. Only when she read the last page of the book out loud to celebrate the Joyce-based Bloomsday Festival while on holiday with friends, however, did she have any notion to transform it into a piece of theatre.

"It was really one of those moments," she says now, "that the tongues of fire descended, and I felt this vibration around the room, and it had this extraordinary communicative effect. I knew then that this would be my next piece, the voice of the river. I started from the idea that she from dissolved into the ocean, and worked backwards from there."

At one point Fouere planned to only perform the last ten pages of the book, but then she became fascinated by the journey of the river itself.

"It's said now that water can hold memory, which I think is a wonderful idea," she says. "It's all a little bit on the borders of science, but they've done these experiments where they play these sounds in water, and there's this idea that water can contain history, which I think is very beautiful."

Born on Ireland's west coast to Breton parents, Fouere has developed a fascinating body of work since she first moved into acting in 1976.

"The 1970s in Ireland were a very low period," she reflects, "and art was the one thing that was like a doorway that opened up all sorts of possibilities. I was drawn to art and medicine, and studied visual art for a while, though not formally. When I started going to the theatre, I thought I might go into it as a designer, but then ended up becoming a performer.

"One of the most beautiful things about theatre is its ephemerality. As a visual artist I don't think I would ever have been happy with what I was creating. It would never be finished, whereas with theatre you have to have the humility to accept that you've got as far as you can before you let the audience in, and then you can continue it together, but it's never complete."

While she has acted with all of Ireland's major theatre companies, including the Abbey and the Gate, as well as the Royal National Theatre in the UK, Fouere has carved out a canon of her own work that fuses image, text and sound. Having been exposed early on to work by the likes of Robert Wilson, The Living Theatre, visiting avant-garde Polish companies and the young Laurie Anderson, Fouere developed a cross-disciplinary approach that began with Operating Theatre, the company she co-founded with composer Roger Doyle in 1980. Over the 28 years of the company's existence, Fouere created and performed in stage and installation-based work drawn from sources such as Antonin Artaud and Sebastian Barry.

Running parallel to this, Fouere took the title role in Steven Berkoff's take on Oscar Wilde's Salome in 1988, and worked extensively with directors Michael Bogdanov and Patrick Mason. For Mason she appeared in Tom Murphy's The Wake at Edinburgh International Festival, where she also worked for Calixto Bieito in Jo Clifford's version of Calderon de la Barca's Life Is A Dream. Fouere toured the world in Mark O'Rowe's play, Terminus, and has just finished a science-fiction film set for release next year. "I've always had two streams to my work," she says, "and that's because I started in the theatre without really knowing at the start of the journey I was on which way to go. Then I started to be offered a lot of mainstream work, and thought I would have to decide, but I've been really lucky being able to straddle both streams, because they inform each other and nourish each other. It's about learning to balance things, but I feel now that those two worlds are coming together a lot more."

Fouere's latest platform is TheEmergencyRoom, which, as well as being the logical step on from Operating Theatre, also implies a sense of urgency about creating a space for what she defines as "work needing immediate attention. It's work that I felt needs to be done, even if it doesn't necessarily have any form of support system other than what I can give it."

This is certainly the case with riverrun, in which life and art come together as one.

"I've always had an exploratory nature," says Fouere, "which is tied up with nature itself and spirituality, so I suppose what I do is kind of a search, but it's also a no choice kind of search. Art is kind of like love, a love you believe in, and which kind of pulls you towards it, and it's up to you whether you follow it or not. It's more than just a want. It's like with riverrun. It's saying for us to wake up, and in that way I hope audiences leave the theatre with a sensation that they can't put aside."

riverrun, Traverse Theatre, July 29-Aug 24, various times.

www.traverse.co.uk