Visual Arts/Aidan Dunne: Franz Ackermann's exhibition at IMMA deals with a number of pertinent issues: tourism, terrorism, globalisation, a sense of place.

Born in Germany in 1963 and currently based in Berlin, Ackermann spent a year in Hong Kong in the early 1990s.

The experience of living in such a heterogeneous, cosmopolitan nerve centre of a city, with its complex cultural and spatial geography, clearly made a deep impression on him.

It mapped the path his work was to take, and spurred him on to further travels to other major cities, including Bangkok, Rome, Tokyo, Manila, Hanoi, Sao Paolo and, in rather odd, fraught circumstances, Dublin.

In 2004, he was one of the passengers on a Lufthansa transatlantic flight that was diverted to Dublin because of a security alert. A threat was received by phone and the plane landed in Dublin for an exhaustive search. Ackermann took photographs throughout the experience and they form part of the exhibition, forming a linear narrative around the wall of one room. The circumstances were exceptional, but the officialdom, queuing, discomfort, anxiety, boredom and sense of suspension are routine and surely familiar to almost anyone who travels by air.

Ackermann's travels shape his work. He is interested in the experience of being a tourist. That is, he doesn't try to claim a higher cultural cause for his being somewhere. It is the phenomenon of mass travel that is his subject matter, though it is not a subject matter that he approaches in a superior or patronising way. He sees the cities that people are drawn to as organic centres of energy, an idea that recalls Kathy Prendergast's series of drawings of cities which views them as, literally, organisms, growing outwards.

Comparably, if less elegant conceptually and materially than Prendergast's drawings, Ackermann's initial responses to his experience of these urban centres of energy are small coloured drawings that he terms "mental maps". The description is a geographer's term for the process by which we orientate ourselves in our environment. That is, searching for somewhere for the first time, you look up a street directory. But we all carry our own unofficial street directories in our minds, maps of place devised according to personal importance and significance.

Ackermann's "mental maps" are personal, idiosyncratic documents, impromptu, schematic accounts of his experiences of place. They feature what may well be accurate records of specific places, but not in readily intelligible, representational form. His own pictorial preferences tend to come to the fore. He likes doodle-like, concentric patterns, bright colours, graphic motifs. In a way, his images are closer to the paintings of Howard Hodgkin than the drawings of Prendergast in the way they look for a abstract visual equivalent of specific places and times.

The drawings are but one strand of what he does. He also makes big, vibrant paintings and extends their grammar onto the walls of the gallery; he makes sculptural objects and installations. Various forms of self-portrait seem to reflect on the status and nature of the individual displaced or in transit.

Following the given pattern of the Royal Hospital, the exhibition takes the form of a series of rooms. We begin with the large, apparently packed plastic carry-all that the artist abandoned in St Mark's Square in Venice during a Biennale, essentially to see what would happen. In the event, nothing much happened, despite our generally heightened awareness of security. Tucked inside the door at the entrance to the show, it makes a suitably provocative, edgy beginning.

The final room isn't all that different, really. It incorporates an elaborate installation, a hotel room in artful disarray, strewn with objects both innocuous and ominous. The occupant could be a typical tourist (or indeed artist tourist), a typical terrorist or indeed a typical terrorist-tourist.

This space leads back around to a dead-end, caged-off area of the penultimate room. All of which articulates an anxiety about mobility and security in a globalized environment of mutable identities and information overload - albeit information of questionable status.

It also articulates a state of transience from the inside, so to speak. But besides articulating these things it doesn't do a great deal with it all. We can recognise something in Ackermann's evocation of atmosphere, something about the mundane facts of living in a contemporary urban culture characterised by unprecedented mobility, recalling Marx and Engel's famous anticipatory description of globalised late capitalism, when: "All that is solid melts into air." But evocation and recognition are not quite enough.

Notwithstanding the installations and sculptures, the drawings and paintings, augmented by wall paintings, are surely the heart of the show, and its centre of gravity resides in them.

Here the question is how Ackermann visualises his concerns, how he sets about devising a pictorial space that will equate to the issues he addresses. The images he makes are kaleidoscopic, multidimensional spaces, incorporating architectonic, geometric and organic forms, motifs resembling signs, as well as bundles of lines like cables and connectors.

Pattern, networks, interconnection, excess: all come across. His palette is heightened, so that the combination of jumbled spaces, concentric patterning and flat areas of garish colour amount to a form of psychedelia that is curiously retrospective in feeling.

Perhaps the strong association of recreational drugs with travel is part of the plan, but certainly the images have a quality of dizzying disorientation that suggests trips of more than one kind. If the paintings don't work, the show doesn't work and, in the end, they do.

They are not at all as ambitious as they think they are, quirky rather than audacious, but they engage the eye and hold our interest, tempting us to negotiate their tumbling, intricate levels.