Gordon is kept in the dark

The Scots video artist Douglas Gordon has a penchant for opposites - light and dark, good and evil, Jekyll and Hyde.

For this show, he's veered heavily towards the last of these pairings, with a series of Polaroids called Black Spot: after the nautical sign for a sailor's imminent death by walking the plank.

In fact, these are overblown mega-Polaroids, pompously framed with funereal black glass and portentously hung against pitch-black walls. Each one shows an out-of-focus image of the artist's left hand, black spot in centre.

It's typical Douglas Gordon fodder in that sensuous rewards for the viewer are few and far between: he doesn't go out of his way to sustain your attention beyond the three seconds needed to grasp what's going on.

Next door, things are more appealing - but only just. A black room with a video monitor shows Gordon's hand (now minus spot) thwacking the camera.

His digits suffocate the light, prod the lens and generally taunt the viewer into feeling giddy. Dark, light, dark, light! It's a sadistic manual strobe - but to what end? Gordon's fellow Glaswegians Smith/Stewart do this brand of psycho-physical video assault more effectively, manipulating each other as well as the viewer.

The rest of the gallery space is given over to Mexico-based conceptualist Francis AlØs. His audio-collage of jazz, circus music and canned laughter permeates the gallery with a nostalgic air of old-fashioned entertainment and accompanies an animation of a chap walking briskly through a park. He forges on, head down, not unlike Woody Allen in gait and demeanour.

Finally, he's met by a yellow pooch, who curls his tail around the man's leg and makes him tumble to the ground. Cue laughter, applause and the man's humiliated struggle back onto his feet.

Studying AlØs's plentiful documentation (sketches, paintings, anecdotes and paperwork) you realise that the man's fall is a metaphor for the ambiguous, clowning role of the artist in society. This is fair enough, and very charming, but I couldn't help thinking how other artists (such as Beuys and McCarthy) have mined this area in bolder, more performative ways.

Conclusion: both shows ooze good intentions but are too slight for lasting impact.

? Douglas Gordon/Francis AlØs, Lisson Gallery, NW1 (020 7724 2739), until 30 June.