Film makers on film: Lynne Ramsay

Today marks a watershed in the Film-makers on Film series. Eight months and 32 interviews after its inception, 33-year-old Glaswegian Lynne Ramsay is the first female director to take part - a pretty fair, if alarming, reflection of film industry ratios.

When I tell Ramsay she's our first woman, she sweetly suppresses a groan. "In the beginning, I used to hate the whole categorisation thing," she says. "Those 'How does it feel to be a working-class female director with a wooden leg?' questions, which ask you to justify yourself for being in a minority.

"But recently, a documentary-maker told me that only two per cent of the world's professional directors are female. Shocking. But I do think that many of our new interesting directors are women, so maybe things are changing."

For now, as one of Britain's most exciting young directors, Ramsay is doing an admirable job of chipping away at the imbalance. Her latest film, Morvern Callar (released yesterday), lives up to the promise she showed in 1999 with Ratcatcher, her poetic debut about a boy's coming of age on a Glasgow tenement.

Starring Samantha Morton, Morvern Callar - an adaptation of Alan Warner's book about an unfathomable young woman from a nothingish Scottish town who covers up her boyfriend's suicide in order to publish his novel as her own - is a triumph of artistic vision. With its lyrical, dreamlike aesthetic and cryptic anti-heroine, it feels hip and hypnotic - a rare experimental gem nestling in this month's heap of releases.

Given Ramsay's tranquil, impressionistic signature style, her favourite film is not an obvious choice. A Woman Under the Influence, made by John Cassavetes in 1974, is an exercise in unflinching domestic realism.

It explores the relationship between construction worker Nick Longhetti (Peter Falk) and his unstable wife, Mabel (Cassavetes's wife Gena Rowlands) as their marriage buckles under the strain of Mabel's spiralling nervous breakdown. Rowlands won an Oscar nomination for her portrayal of a woman constantly veering between endearing theatrics and screeching hysterics.

For such a small-scale movie - most of the action takes place in the Longhettis' house, among their family and close friends - it is remarkably noisy. Mabel, fuelled by drink or prescription pills, shrieks; Nick hollers; their three kids yell at them to shut up; and Mabel constantly entreats Nick's friends to sing her favourite opera arias.

I put it to Ramsay that the film feels like living next door to a family from hell. "Watching it is an intimate and uncomfortable experience," she says. "But when I first saw it on video about seven years ago, I just couldn't believe that you could get such an emotionally intense experience from a film. I was completely numbed and just sat there for about two hours afterwards thinking about it.

"The performances are so real, especially Gena Rowlands's. I believed every moment of it, and I felt intensely sad for her because her spirit gets broken when she gets committed to the mental institution. At the start, she is verging on madness, but it's part of her quirky personality, part of what makes her great. She's like a kid getting over-excited and Nick, although he really loves her, just can't deal with it."

As with many of Cassavetes's films, A Woman Under the Influence was released to general critical disdain for its elevation of character above plot and its rough, erratic look. Retrospectively, Cassavetes (who died in 1989) shines as a trailblazer for America's take on cinema verite - or the "patron saint of American independent cinema", according to the critic Ray Carney.

"His style was very pure, completely centred around the performances," says Ramsay. "It was a precursor to a lot of directors, like Woody Allen. Some people would say that it was a non-style, but I love it. Cassavetes concentrates his camera so closely on the actors, using handheld in a way that was really ahead of its time.

"It's a bit like documentary, but it has an intense energy, so you feel very intimately involved with the characters. It feels like you've spent real time with them, gone through this complete emotional experience with them."

Cassavetes's "non-style", says Ramsay, could be defined as an aesthetic in itself: "There are some lovely shots in the film, especially when Peter Falk's character is on the construction site. Cassavetes just uses 'available light' - natural light - and the minimalism has a real beauty.

"You never feel that there's been this huge faffing around trying to get a set up, which is something I always try and avoid, too. I think he knew that pared-down style suited what he was trying to do. He wasn't coming from a technical point of view, but he really understood film-making."

For Ramsay, his overwhelming strength lies in the complexities he teases out of his characters. "He gets inside their heads," she says. "All his films show a real understanding of the human condition. I think because he was an actor [he appeared in films such as Rosemary's Baby and The Dirty Dozen], he understood what the demands are on his cast - how vulnerable actors can feel.

"Gena's performance is so raw that you can tell how much she trusted him. Even without knowing they were married, you can sense that the relationship between them must have been more than professional.

"It's difficult to talk about influences, but when I saw the film I definitely thought the way he explored character was something I was interested in, too. There was a real risk that Mabel would just seem plain insane. But I never felt that; she was so three-dimensional.

"In modern cinema, everything's often so plot-driven around stereotypes like the cute kid and the good guy, everything's so bland and homogeneous. But this film was completely inspiring. These two people are flawed and miscommunicating, but there's still love there.

"How often do you see a film that dissects emotions from every point of view rather than inviting you to identify with just one character? That's just fantastic."