LONDONFIELDWORKS

Everybody likes have-a-go art for the same reason we love interactive exhibits in museums - it brings out the child in us. So it's good that there's so much of it about. Recently we've had Mike Nelson's creepy installations at the ICA and Tate Britain, Keith Tyson's unfathomable and outsized game at the South London Gallery and now Polaria, a collaborative work at Wapping Pumping Station billed as "an interactive light installation for an audience of one". And it's wonderful. This is how it works: you arrive in a dark and freezing boiler house to be confronted by a glowing cube the size of a domestic room. Around it, four giant photographs of barren landscapes are displayed on light boxes. These pictures taken in Greenland by Anthony Oliver during the summer months of 24-hour daylight are a clue to what you will experience inside.

Dressed in a padded white jacket and cloth shoes you enter the box, sit in a clear acrylic chair and place your hands on the two bronze panels on the arms. This is where the fun starts as a gentle electric currrent pulses through your body. When you make this connection the light in the room changes. With your hands flat on the bronze you get a bright white light. But as you wriggle your fingers and lift your hands the shade changes to blue-ish white, yellow and orange. It's blinding at times, but also beautiful and strange. You might be happy not knowing what any of this is about. But if you're the inquisitive or scientific type, artist Bruce Gilchrist and lighting designer Jo Joelson are on hand to tell you the exact nature of their research.

What you experience inside the room is a virtual representation of the summer light levels in Greenland, as measured by Joelson. And you trigger these as your own electronic skin resistance levels shift to match those of Gilchrist which were also measured during the pairs stay. It sounds complicated, but you can take or leave the data. And in any case, the artists themselves admit "there is as much shamanism as science going on", which makes the experience of Polaria all the more delightful.

Four lightboxes show a barren landscape in Greenland photographed by Anthony Oliver at 6am, midday, 6pm and midnight. In three of the images the light is cold and bright - like a crisp, clear, English winter day. Only the midnight shot has a warm glow; it was summertime, when daylight lasts 24 hours. Bruce Gilchrist and Jo Joelson spent a month in Greenland measuring the light falling on to and reflected from objects such as flowers, rocks and their own skin. In the boiler house at Wapping, they offer the chance to experience a comparable range of warm and cold light. You sit on a translucent chair in a white cubicle and place your hands on two bronze electrodes so completing a circuit that activates light panels in the ceiling. Resting my hands lightly on the electrodes, I was bathed in a cold, brilliant light that occasionally flickered warm before returning to limpid coolness. During a second session, a powerful tingling travelled up my arms as I pressed my palms firmly on the plates. When I realised that changes in touch altered the light, the experience became less meditative and more like an interactive game. On the way to Wapping I had noticed how tired I felt. After my irradiation I was more alert and, that night took a long time to go to sleep yet, in the morning, I woke early and energised. Given that dragging myself out of bed had proved more difficult each day - as though I'd been over- taken by a desire to hibernate - this felt like a rebirth. SAD - seasonal affective disorder -is a recognised form of depression caused by winter gloom, which can be treated with light therapy. If the winter blues are sapping your vitality, absorb the dose of pure energy offered by Polaria.