WHEN Leonardo di Caprio began his acting career as a child, he quickly became known as a sensitive performer with a unique combination of innocent, ?angelic? looks and a penchant for playing psychologically troubled youths.

This unusual mix of potentially ?contradictory? impulses did a lot to make him stand out, and he was eventually heralded as the leading teen dramatic actor of his generation.

When DiCaprio moved into his young-adult years, his screen image was gradually tweaked to transform him into a more ?mainstream? lead player.

Big transition

The big transition vehicle for him was James Cameron?s super-blockbuster, ?Titanic,? and the fact that it ended up becoming the biggest grossing film of all time was in part positive proof of the success of his career-boosting gambit.

Later, DiCaprio made a series of movies with the esteemed filmmaker, Martin Scorsese, who effected another major change in the actor?s screen persona by transforming him into a tough action-drama star.

That was a difficult change to pull off, because the actor was better known for his sensitivity than for his macho toughness.

Survivors

Luckily for DiCaprio, Scorsese is a past master at textured action-dramas about survivors faced with daunting choices in life. His expertise effected a successful transformation for DiCaprio, positioning him to star for many more films to come in the ?maturing? phase of his career.

DiCaprio?s current starrer, ?Shutter Island,? is very much along these lines ? but, it?s particularly significant, in our view, because it is able to combine the actor?s new, tougher image with the sensitivity and troubled vulnerability with which he first made his mark as an actor.

Scorsese?s action-drama films have always had a dark psychological component, but ?Shutter Island? is particularly dense, complex, convoluted and inward-looking.

Very definitely, things are not what they initially seem to be in this psychological ?whydunnit,? and DiCaprio benefits from its especially charged dramatic environment, because he?s given a lot to work on and explore in the movie?s many thespic conundrums.

At its simplest, ?Shutter Island? is about an officer of the law who?s sent to a facility for the criminally deranged to investigate the baffling disappearance of one of its female inmates.

Complex fiction

Slowly but surely, however, this basic matrix of ?facts? turns out to be a complex fiction created by a demented mass murderer.

Why the huge fictive cover-up? So that the insane criminal can live with himself despite the horror of his crimes ? well, just barely.

DiCaprio takes full advantage of the major thespic challenge he?s given in this psycho-drama ? and he looks like he?s having the time of his life as he revisits the troubled psychological roots of his youth.

This time around, however, he?s a maturing actor in full control of his dramatic skills and faculties, so the results are richer and deeper than ever before.