Keith Tyson: Studio Wall Drawings 1997-2007, Haunch of Venison, London

Feverish unfinished symphonies

Process, that's the word. Artists and writers are very fond of it. The New York poet Charles Bernstein is a big practitioner. It means that the work that you see, on the page or on the wall, is still in momentum, still in the process of being made, and perhaps even that the work itself is mainly a testament to that fact.

The consequence of this is that it's often rough-edged and raw-edged, quite hot and squirmy. Yes, never dry and cold and polished and slickly finished such as, say, Poussin, because what we are witnessing is as much the hand of the ever-restless creator as the thing that they have created.

Furthermore, when it's work-as-process, we feel that what we are seeing could easily be a part of something else that's still to come, or the tail end of something that is just drawing to a close, if indeed it ever draws to a close before death puts paid to the mind that's fashioned it. It's never crisp and over. Never THE END. In fact, process means that we are peering directly into the whirring mechanism of the human brain on heat.

Keith Tyson's work is like that. It was exactly that when he won the Turner Prize in 2002, and it still is today. This is a show of wall drawings from the studio from the past 10 years, huge panels in a multiplicity of wild styles that, on the uppermost floor of this three-floor gallery, are hung cheek by jowl together, great, louring walls of them. One wall consists of 24 such panels, each one the same size, each one framed fairly modestly and penned behind glass.

Tyson's a feverish fellow who seems to spend all his time thinking, and showing us that he's thinking. He thinks about geometry. He thinks about scientific problems. He thinks about cosmology. There's nothing he doesn't think about. His works spill out of him on to the wall (in this case) rather like the mathematical formulae that used to spin out of the chalk end of the maths master on a Thursday afternoon and you were wishing you were somewhere else. You peer, somewhat bewildered and awestruck, at a blizzard of signs, formulae, inventions that look a bit like brilliant wheezes, and would surely be if only you could be even 90 per cent sure that you'd got the hang of them.

Ideas seem to be coming at Tyson from all angles, night and day, and the only thing to do is to get them down as quickly as possible. It's an act of exorcism. There are always yet more demonic ideas lined up behind the last one, heaving their way out of the hot, seething darkness of his brain, and into the light of day.

Like a Chinese army, it just seems to go on and on, noisy, unstoppable, brashly impressive in its way, but also pretty exhausting to decipher. Tyson doesn't draw in any particular style because he draws or scribbles or doodles in all styles at all times, perpetually shifting from one manner to another, and almost everything is almost always overlaid with words, words, words fragments or snippets or scraps of things overheard or over-read. Nothing that ever adds up to much, though. Just a snatch of his teeming world. In short, he's a kind of authorless machine of fantastic visual notions, some cartoonishly grotesque, others eggheadish.

Take a look for yourself. It feels a bit like being bashed about by a pro boxer over umpteen rounds. You are not quite sure whether to laugh or cry at the end of it. Nor are you quite sure whether you like it or not, nor indeed whether it's much good or not. It has a kind of browbeatingly impressive presence all the same.

To 5 January (020-7495 5050)