VISUAL ARTS: Tino Sehgal ICA London ooo99

AS I WALKED up the staircase towards the upper gallery at the ICA, I encountered a man at the top standing with his back to me. When I entered the gallery, it was empty except for four people standing facing the walls. They seemed to be mumbling. Slowly, the mumbles became louder, and I could decipher phrases such as: "The object of this work is to become the object of a discussion, to create some sort of reaction." Questions were posed and reactions bounced backwards and forwards between the two women and two men. At all times, they stood with their backs to the centre of the room, so I couldn't see their faces.

Another man entered the gallery. He seemed to be a punter. I wondered if he was wondering if I was part of the work. He went up to one of the mumbling men and stood in front of him. The man turned away to face the wall. The proposals and counterproposals between the four continued. Then it was suddenly over.

In the lower gallery, a man rolled very slowly across the floor. His eyes were closed. As he rolled, he pulled his knees up into a foetal position or put his arm over his face as if hiding some inner torment. I crouched beside him. He continued his movements, ignoring me.

This is the first of three solo exhibitions at the ICA over a three- year period by the London-born artist Tino Sehgal. Sehgal, who lives in Berlin, has a background in choreography and economics, both of which inform his work. Born in 1976, he has shown throughout Europe and been selected to participate in the German pavilion at this year's Venice Biennale.

His belief that art and society are inextricably related, that both are reliant on the production and exchange of goods and commodities, imbues his work. The scenarios he orchestrates concern the transformation of acts and the production and exchange of ideas and meaning. Without producing anything tangible or creating objects of any sort, these transitory situations investigate fundamental philosophical issues.

Yet all that exists is a series of gestures and words that have been worked around a skeletal theme. Sehgal's only materials are the human body and the voice. The results are deeply affecting, disrupting and thought- provoking. The roles of viewer and performer become blurred, as do questions about where meaning resides, and who creates and who interprets it.

In such a materialistic age, this is a revisitation of the political interventions of the Sixties, then known as "happenings". There is something refreshing about this work that is both modest and yet far-reaching. Without glitz and spurious clutter, Sehgal stakes out a radical position within the tradition of sculpture and installation. In so doing, he returns art from the arena of the marketplace to one of aesthetic debate and humanistic questioning, where it most readily belongs.

To 3 March (020-7930 3647)