There is nothing warm, fuzzy or even erotic about Steven Soderbergh’s The Girlfriend Experience, a movie bound to be remembered as much for its leading lady’s other on-screen exploits – she’s world-famous porn star Sasha Grey – as for its clinical depiction of a high-priced Manhattan escort as a passionless pro.

Is that a failure on Soderbergh’s part? Not at all. If anything, The Girlfriend Experience, which finds the Ocean’s Eleven director indulging his impulse to experiment (as he did in 2005’s Bubble), is all too effective in revealing the vast emotional chasm that separates Chelsea from her clients. They talk, she listens. Sex is a given, most of the time. Money is exchanged.

That, it seems, is the movie’s dominant theme. For Chelsea, her personal-trainer boyfriend (Chris Santos) and everyone else who steps into her cold, business-oriented world, life is a series of transactions. Sex and romance can be negotiated as easily as a three-piece suit. Chelsea chronicles her close encounters in her diaries, but rarely does she reflect on intimacy or feeling. She remembers her clients by the designer dresses she wears for them, and whether or not they scheduled another session.

It’s no coincidence that The Girlfriend Experience is set in October 2008, with America’s economy in shambles and the presidential race near its conclusion. The language of commerce is everywhere, in the bedroom and at the dinner table, whether it comes in the form of investment tips (one client helpfully advises Chelsea to invest in gold) or a debate over Obama’s recovery plan. Chelsea, ever the self-contained ice queen, takes it all in without apparent interest, but she’s polite, she smiles, and she plays her part well.

Does it bring her joy? There are moments, yes, but none so gratifying as the time-outs for calculating her earnings. Chelsea is withdrawn even from those she keeps close – her boyfriend, we learn, is just as disposable as the rest – making it all the more shocking when she lets down her guard, just for an instant, to reveal a well-hidden capacity for pain.

As she admits during one of her dryly recited confessionals, her clients don’t want the real Chelsea, whoever she may be – they want a girlfriend of their own imagining, submissive to their every whim. The real Chelsea is too fiercely guarded to be known, certainly to us and perhaps even to herself. Her life is a series of well-paid masquerades, and the disconnect is too profound to overcome.

Grey, a self-made entrepreneur in her own right, must have a few things in common with Chelsea, and though she’s hardly charismatic in her mainstream debut, she’s right for the role. Soderbergh keeps his camera fixed on her, capturing every fake laugh and hollow smile. The result isn’t always pretty – it’s uncomfortable at times, frustratingly inert at others – but it feels true to life and to the less glamorous side of human nature. For that, respect must be paid.