Ríonach Ní Néill's new dance piece is written in the knowledge that watching it could transform some people's lives, writes Michael Seaver.

It's all been done before, according to choreographer Ríonach Ní Néill. There isn't a theatrical convention that hasn't been dismantled, ignored or set up for ridicule. And audiences have played their part. They've traipsed around galleries following dancers, answered obediently when spoken to by the cast, had lights shone in their face and, for one unfortunate member during Nigel Charnock's Frank last May in Project, had their handbag swiped, emptied onstage and contents carefully examined. Yet the advance publicity for How did we get Here?, Ní Néill's latest dance, claims that "the relationship between performer and audience will be turned upside down and inside out".

Isn't the old rule of engagement being challenged again? Not quite. What takes place on the Mermaid's stage tomorrow night is not a confrontation with convention or audience. Whereas other artists have sought to shake the audience (passive consumers) out of their stupor and bully them into being more involved in the performance (a worthy event), Ní Néill sees no need to patronise or face down the audience. Instead there is a more fundamental question that needs answering, namely, how did we get here? "I'm curious what brings the audience and the artist into the same space, this small black box", she says. "What do we want from each other? What is this contract that we have approved by being here together?" The question may have been asked in the past, but hardly as conciliatory or considerately. Ní Néill is constantly respectful of whatever led people to choose to spend time looking at her choreography.

"I decided to do short vox pops with random people in coming up with material for the piece. The question was simply, "Why do you go to the theatre?" and I asked a huge cross-section of people, from family and friends to complete strangers. To my surprise, not one of them came out with the usual 'I love to watch dance because it is so graceful and ethereal' or 'It's so calming to watch dancers and they work so hard'.

'TO MY SURPRISE, everybody said, and this includes the non-dancers, that they come to the theatre to change how they think. And for some, to help transform their life." This changed everything. Out went any grand ideas to either confront or entertain the audience. Ní Néill realised that if people were this sincere, she was obliged to say what she needed to say, rather than what she thought the viewer expected her to say. "It liberated me. These interviews gave me the go-ahead to ditch anything that was veering towards crowd-pleasing. Instead I'm now communicating to the audience with complete honesty."

Dance is good at both. It can seduce the eye with relaxing fluidly changing shapes but also speak with an unerring visceral directness. Freeing up the mind cropped up in the interviews, something else dance is good at.

"People kept saying that they watched dance because it gave them space to dream, and this mental relationship between artist and audience is far more interesting than the physical one. We're supposed to be clever so much these days, understanding everything and able to 'get it' when in the theatre. Dance allows the audience's voice to be heard - in their own head."

In our overly prescribed lives, ruled by endless to-do lists or Sat-Nav, the multiple meanings in movement allow the mind to wander productively, rather than have it become enslaved to a plodding narrative.

Ní Néill is anxious not to be too touchy-feely about all this and, on the evidence of an incomplete run-through, How did we get Here? credits the audience with visual and physical sophistication. In some ways, the work is also a reaction to her years at Tanztheater Bremen, performing in what she jokes was an assembly line. "Not in making the work - we had a wonderfully creative process - but certainly as a performer.

"I did a premiere five months pregnant, and another with torn ligaments, so my foot was literally falling off my leg, but you push through it and keep going. It could so easily become just a job." German audiences were certainly institutionalised, and attendance at various events was an indication of your class, standing and how much money you had. That's something she noticed in Ireland on moving back.

"In some ways, it's not surprising that people are coming to the theatre for a mind-changing experience. It's really not acknowledged how much of a crisis we are in with materialism. That can't feed you completely, it's not enough of a reason to get out of bed in the morning. Then there is that engagement in community that happens in the theatre, an interaction that is becoming rarer."

ALTHOUGH DISMAYED WITH materialist Ireland, reckoning it is still a difficult place to create work, she rejoices in the improvements in the dance infrastructure.

Unlike the grubby studios of the past How did we get Here? was the first complete work created in the new Dancehouse in Dublin city centre. Not only were the floors clean, the choreography could be created to scale in the large studios.

"There was this beautiful neutrality or sterility in those bright, airy, white-walled studios. Coming into the black box you lose some of that. It's not a neutral space because you have to contend with the ghosts of the past and some of them have big stage egos that you can't get rid of."

But it is only in this place - the site where she will engage with the audience - that her choreography and ideas fully coalesce. The final shape will form when the audience choose to go along and sit in their seats.

• How did we get Here? will be performed by Ciotóg at Mermaid Arts Centre, Bray, Co Wicklow tomorrow at 8pm, followed by performances at Project Arts Centre and a nationwide tour later in the year.