Visual Arts/Aidan Dunne Reviewed:  Phil Collins: They Shoot Horses, Kerlin Gallery, Dublin, Guy Bar Amotz: The Dance Machine, Project, Dublin, Cora Cummins, Kevin Kavanagh Gallery, Dublin, Brian Henderson: Sangoma, Taylor Galleries, Dublin, until May 31st (01-6766055)

Phil Collins's They Shoot Horses takes its title, and its rationale, from the Sydney Pollack film based on Horace McCoy's novel about dance marathons during the Depression. Desperate people submit to a gruelling physical ordeal with a faint hope of material reward. Driven to suicidal despair, one puts a gun to his head and offers, by way of explanation: "Well, they shoot horses, don't they?"

At this stage of his burgeoning international career it is fair to say that Collins's great skill, perhaps his greatest, is negotiation, in the sense that he gets himself in to difficult situations and has to negotiate his way through them. The works emerge from this process. Earlier this year, with some difficulty, he negotiated his way in to Ramallah, in Palestine, to stage his own disco marathon. The seven-hour, two-screen video installation is the result.

On one screen are enthusiastic amateurs, on the other seasoned professionals, all dancing to a non-stop soundtrack. As the hours go by they drop out one by one. The pros are canny. They pace themselves and co-ordinate with each other to conserve energy.

A recurrent feature of Collins's work is the intimation that, once you get beyond the way their identities are represented or caricatured or travestied, people are all pretty much alike. And that holds true in this piece, which offers quite an alternative view of young Palestinians.

Yet despite the real empathy, the humane core of the project, there is also a toughness about it: it never degenerates into a feel-good fest. It's as if Collins is mindful of Jerry Seinfeld's two golden rules of sit-com writing: no hugging, no learning.

In fact there is a cool, almost anthropological aspect to it in the way Collins generates layers of ambiguous meanings. On the one hand we can interpret the exploitative marathon as an allegory of the plight of the Palestinians. But, in relation to the way individuals are nudged and prodded towards suicidal despair, the question of who is exploiting whom is left open. Apparently, the piece is about an hour shorter than originally intended. At some stage in the exhaustive process of getting the original tapes out of Ramallah one of them went missing.

Dance features in a different way at Project. The centre's visual-arts curator, Grant Watson, has from the first put an emphasis on the performative in his programming, so it's logical that he should go for Guy Bar Amotz's The Dance Machine, which, while physically imposing as a sculptural installation, is about as performative as you can get. Part of a collaboration with International Dance Festival Ireland, which involved a choreographed performance by Jasmin Vardimon, Bar Amotz's piece transforms the gallery in to a primed, interactive space.

It's primed with a video camera and electronic sensors that pick up on your movements once you enter the gallery. Huge, eccentric-looking speakers are liberally distributed around the floor. Some are improvised and incorporate workaday objects, others are elaborately shaped, smoothly finished objects designed to be worn. A battery of electronic apparatus translates your movements in to sounds, big sounds that issue from the various speakers, so you create, although don't quite control, both images and sounds through your movements. The technology works, and the whole experience is challenging and involving, interactive to a degree beyond the usual anodyne sense of the term.

Cora Cummins's etchings are part of an ongoing landscape project. She has long displayed an ability to make subtle, beautifully judged evocations of space in her print works. While the images are always atmospheric and come across as being directly linked to the reality of specific places in terms of textures, colour and tone, there is also an analytical element to them. In her recent works she has been considering specific kinds of landscape spaces - typically, contained urban spaces.

They are all constructed environments, even Wildflower Meadow, with its expanses of blooms, an example of calculated randomness, a representation of nature rather than nature itself. Other subjects are more obviously designed: the stand of flowering cherry trees, a perennial favourite in municipal and architectural planting schemes, the unreachable oases of roundabouts like luxuriant deserted islands in seas of motorways.

These fragments of natural elements evoke a nature that is always somewhere else, if anywhere at all, given that the wider landscape has been co-opted in to the narrative of heritage, as one work, Heritage Bump, implies. But they do provide breathing spaces, even when, in the form of traffic islands and roundabouts and golf courses, they remain largely inaccessible. Although they are relatively spare and understated, Cummins's prints have great individual presence.

Brian Henderson's Sangoma is a series of collage paintings. Layered and sculptural, it is as if in each case a picture plane has been opened out, deconstructed and reassembled. If that sounds a lot like cubism, it should. The exuberance of later Frank Stella is one obvious point of reference; the quick-witted brilliance of Picasso's sculptural collages during the height of cubism is certainly another.

Henderson aims to build up a momentum in each piece, using bold, gestural patterns, tears, folds and hard edges. He is sparing with colour, surprisingly so in a way, because when he uses it he does so to great effect. His aim is at least partly to keep the eye moving and the mind guessing, to get us to try to make visual sense of the compositions. In their buoyancy and inventiveness they could correspond to the energy and atmosphere of a buzzing city.

Phil Collins: They Shoot Horses, Kerlin Gallery, Dublin, until June 5th (01-6709093)

Guy Bar Amotz: The Dance Machine, Project, Dublin, until May 29th (01-8819613)

Cora Cummins, Kevin Kavanagh Gallery, Dublin (01-8740064)

Brian Henderson: Sangoma, Taylor Galleries, Dublin, until May 31st (01-6766055)