`I DON'T REALLY NEED TO BE FLAMBOYANT'; LEIGH LETS HER QUIRKY WORK DO THE TALKING.

Byline: Bob Strauss Daily News Film Writer

What is reality?

The ultimate psychedelic era question is back in vogue again, what with mind-bending, is-it-real-or-is-it-virtual movies like ``The Matrix,'' ``Open Your Eyes'' and David Cronenberg's latest, ``eXistenZ,'' filling theaters.

The same question applies to ``eXistenZ's'' star, the professionally provocative, personally subdued Jennifer Jason Leigh. In her work, she's been as bold as an actress can be, even in an age when outrageous risks have been a badge of artistic seriousness. But off screen, the 37-year-old actress is a shy, bookish homebody whose idea of a good time is playing with her dog, immersing herself in research and nerding around on the computer.

``I don't really need to be flamboyant,'' she explains. ``Plus, I don't have the energy for it, let alone the inclination.''

There are more contradictions. Though she's a child of Hollywood - Dad was the late actor Vic Morrow, Mom is screenwriter Barbara Turner, and she took the middle name as a tribute to family friend Jason Robards - the actress has always leaned creatively toward the independent film movement, especially its most extremely independent faction. And even on the rare occasions when she's made studio pictures, Leigh has opted for dramatically interesting over star-making roles.

From her earliest work as one of TV's first anorexics in ``The Best Little Girl in the World,'' Leigh has created an indelible gallery of troubled women. There was one of the movies' most memorable pregnant teen-agers in ``Fast Times at Ridgemont High.'' There have been enough dysfunctional relations to fill a Corleone family reunion (``Sister, Sister,'' ``Georgia,'' ``Dolores Claiborne,'' ``Bastard Out of Carolina''), and she's played enough numbed-out sex workers to stock an escort service (``Miami Blues,'' ``Last Exit to Brooklyn,'' ``The Men's Club,'' ``Short Cuts''). The list of self-destructives ranges from ``Single White Female's'' psycho roommate to the brilliant Dorothy Parker (``Mrs. Parker and the Vicious Circle'') to ``Cabaret's'' Sally Bowles in the hit Broadway revival.

Having just come off that demanding, audience-interactive musical - her first major live theater job - Leigh looks particularly waiflike, having chopped off most of the hair she dyed black for the role. Anything that dark can't be bleached back to her natural light blond, she explains, so the hair was just one more sacrifice made for her art.

It was that kind of dedication, coupled with her willingness to push the behavioral envelope, that convinced Cronenberg that Leigh could bring his ``eXistenZ'' to life.

``Jennifer playing the lead in this movie was not just about acting, but the kind of tone and ambience she can create,'' says Cronenberg, whose films - ``Dead Ringers,'' ``Videodrome,'' ``Naked Lunch,'' ``Crash'' - mix astute philosophical speculation with alarming, grotesque imagery. ``She can be beautiful and sexy and glamorous, which she is in this movie, but also nerdy and shy and withdrawn. She can do all of that stuff totally convincingly and then morph from one of those moods into the next.''

Leigh agrees that the collaboration with the biotech-obsessed Cronenberg was a match made in cyberpunk heaven.

``David's just got such an original vision, full of extraordinary details,'' she says. ``I love working with people who really stick by their vision - and it's something that they want to do, not something they're hoping to please a bunch of people with. And sometimes there were three levels of reality going on, which made it challenging but also lots of fun.''

In the strange, near-future world of ``eXistenZ,'' which opens Friday, Leigh plays Allegra Geller, an introvert who blossoms in the elaborate, make-believe worlds of the best-selling virtual-reality games she creates. By this time, games have evolved beyond computer and video screens into semi-organic entities that plug into players' bioports (insertion jacks mechanically installed at the base of their spines), so the hallucinatory program can interact with the players' central nervous systems.

This lucrative, addictive technology has entranced millions and inspired a Realist underground of radicals opposed to people spending their consciousness in this virtual dream world. They've put a price on Allegra's head, and with an inexperienced bodyguard (Jude Law) she tries to escape their assassins both inside and out of the dimension of her new game, eXistenZ.

Got that? If not, rest assured that there are more twists involved. Some pretty gross specifics, too, ranging from fleshlike game pods to a weapon called a gristle gun to the sweet-and-sour mutant amphibians served in a cyberspace Chinese restaurant.

``The restaurant was pretty disgusting, yeah,'' Leigh admits. ``The stuff on that plate was edible, but it smelled ba-a-ad. Lucky for me, Jude had to eat most of it - and he's a vegetarian.''

Gross or not, Leigh committed to Cronenberg's project fully; so fully, in fact, she had to sacrifice her part in the last film by the ultimate independent filmmaker, Stanley Kubrick.

Leigh had filmed a few scenes with Tom Cruise for the maestro's two-years-in-the-making erotic thriller ``Eyes Wide Shut.'' But when the perfectionist director wanted to reshoot them months later, she was in the middle of ``eXistenZ's'' Canadian production and could not leave for Kubrick's London set. Her scenes were reshot with Cruise and another actress.

``It was a huge disappointment, but what can you do?'' she says stoically. ``The thing for me to hold up is that I had the experience of working with him, and I loved it. That was not disappointing; he was such a mensch, sweet and nothing like the stories everyone hears about how he was so hard to work for. He was quite open, let us improvise; it was so luxurious. He cared so much and was so smart and funny.''

Kubrick died in March, hours after completing his final cut of ``Eyes Wide Shut.'' In honor of the secretive genius's wishes, Leigh refuses to divulge any story information about the movie.

She is thrilled to mention her next project, though, a film scripted and about to be directed by her mother, in which Leigh plays a hotel chambermaid who takes way too much interest in the guests' personal business.

Leigh admits that after creating a wide array of bizarre characters, finding roles that suit her tastes is getting harder.

``I hate generic anything because I don't feel anything from it,'' she says. ``And I don't want to repeat, so I really look for things that I have an immediate response to and I think are really interesting. Sure, it's not easy, because I have done a lot. But choosing roles is not really a cerebral process for me. I just read something and think, `Oh, I've got to do this character.' ''

Leigh has stuck to her guns throughout a distinctive career and maintained her personal equilibrium along the way. A lot to be proud of - or at least enough to make her feel comfortable about herself. But Leigh admits that she's still painfully self-conscious around people, especially when she doesn't have scripted dialogue to fall back on.

``I'm less nervous about it, but I'm still very shy outside of work,'' she confesses. ``I am proud of my work and happy about my life. But I guess I just don't feel that articulate, so I always feel like I'm not expressing myself in the best, most evocative manner. All the things I feel proud about in my acting, I don't think I do justice when I try to describe them.''

Leigh sells herself short, and you wish she wouldn't. But at the same time, you don't want her to change anything that keeps her more interesting than she even realizes.

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2 Photos

Photo: (1--Cover--Color) An unusual `eXistenZ'

Risky roles accent the life of an otherwise tranquil Jennifer Jason Leigh

(2) Freshly shorn after darkening her blond hair for ``Cabaret,'' Jennifer Jason Leigh stars as a designer of virtual-reality games in ``eXistenZ.''

John Lazar/Daily News