A colourful return for man who inspired the Young British Artists

He is one of the defining conceptual artists who taught and influenced Damien Hirst and his fellow YBAs (Young British Artists). Now Michael Craig-Martin is returning to London with his first major exhibition in the city for seven years.

The show at the Gagosian Gallery, entitled "A is for Umbrella", reveals how computers have become central to Craig-Martin's work and also marks the first time he has used letters and text in his art.

One of the highlights of the exhibition, which opens today, is a series of computer-generated self portraits in the artist's trademark bright palette, in which the different features hair, eyes, brows continuously flash, fade and change colour.

Craig-Martin, who works with the help of a software adviser, uses high-definition, 52-inch monitors with a computer custom built into the back. Each one is programmed to perform different operations at random.

"I'm always at the edge of what's technically possible. I use very high definition monitors. It's only in the last year or two that it's been possible to get monitors at that definition," he said.

He added: "If I didn't have the computer, I couldn't have done anything I've done for the last 10 years. When I first started using computers, there were very few artists using them and even fewer who would admit to using them."

Now, Craig-Martin believes, the use of computers in art is more accepted. "I don't think anybody thinks less of you if you use a computer," he said.

Born in Dublin in 1941, Craig-Martin was raised in the US, where he studied fine art at Yale University. He came to Britain in 1966 having been offered a teaching job at the Bath Academy of Art. In 1973, he began teaching at Goldsmith's College, London, where he influenced a generation of students in the 1980s and 1990s, including Hirst, Tracey Emin, Julian Opie, Sarah Lucas and Gary Hume.

His first solo exhibition was in London in 1969. Three years later, he participated in the definitive exhibition of British conceptual art, "The New Art" at the Hayward Gallery.

One of his best known works was An Oak Tree (1973), a three-quarters-full glass of water sitting on a high shelf. It was accompanied by a text which explained the physical substance of the glass of water had been turned into that of an oak tree.

The art magazine Apollo recently said that like Hirst, Craig-Martin's work was clearly marked by his Catholic upbringing and described An Oak Tree as "almost a commentary on the doctrine [of transubstantiation which holds that the holy wafer and wine are literally transformed into the body and blood of Christ]".

Craig-Martin is also known for his large-scale public works, sculpture and for his brightly coloured paintings of everyday objects, which he draws in outline. It was the latter which have inspired new works in the exhibition containing letters, spelling out the words "Art", "Sex" and "God".

He said: "The paintings all use letter forms and words and I've never done that before. I've always drawn objects as outlines. I've often thought about using text and words, but I wasn't sure how to integrate the two, so I had the idea to draw the letters the same way as I draw objects.

"All the words I've used are very ordinary, but they're big abstract considerations for which there's no picture, so I've decided to use the word."

Louisa Buck, the contemporary art correspondent for The Art Newspaper, said: "Michael Craig-Martin is one of our most senior and influential figures who combines acute conceptual and aesthetic rigour with a refreshing lack of stuffiness in allowing his work to be let loose on the exteriors of buildings and interiors of restaurants as well as the walls of galleries."

The 1980s generation

In the late 1980s, a generation of artists who came to be known collectively as the Young British Artists (YBAs) arose. Goldsmith's College in London was a focal point and Michael Craig-Martin, who worked there, was one of the most influential teachers.

While there was a huge range of diversity among individual artists, Tate Online says: "Formally, the era is marked by a complete openness towards the materials and processes with which art can be made and the form that it can take."

Although Craig-Martin said he didn't see his individual pupils as part of a wider phenomenon "I never thought of them as a movement" he taught and nurtured some of the main YBA protagonists. One was Tracey Emin, who turned her slept-in bed into a work of art and constructed a tent into which she had sewn the names of everyone she had ever slept with. Another disciple was Damien Hirst, who became famous for preserving dead animals and is now one of the most powerful figures in the art world, the creator of a 50m diamond encrusted skull entitled For The Love of God.

Sarah Lucas, who used a table, melons and smoked fish to make a crude visual pun in her 1995 work Bitch, and is also known for her uncompromising self-portraits, was also a pupil. Julian Opie, who worked briefly as Craig-Martin's assistant, became known for his metal sculptures.