A World War II veteran and tabloid journalist who converted a slambang shot-from-the-hip prose style into an equally punchy and aggressive film technique, Fuller's films aren't exactly what you might call subtle, but they're hugely inventive (especially considering their usually rock-bottom budgets), performed with commendable gusto, and throw out more genuinely thought-provoking ideas and weird poetry than many films with far more lofty artistic ambitions.

It's easy to criticise them - Shock Corridor walks a perilous tightrope between being a serious study of mental illness and pure trashy exploitation (the magnificently OTT "nympho ward" scene alone shows just how far Fuller was only too happy to go in the latter direction!) - but it's hard to ignore them, and impossible to dismiss them: even at their most gratuitously loopy (and both Shock Corridor and its companion, Naked Kiss, contain moments of quite jaw-dropping dementia over and above their settings), they have a formidable visceral and intellectual impact. You certainly know you've seen something when you come out of a Fuller film, even if you end up fleeing for the exit.

Shock Corridor is about Johnny Barrett (Peter Breck), a fearsomely ambitious journalist who gets himself locked up in a mental hospital in order both to investigate a murder and to win a Pulitzer Prize - significantly, he seems more attracted by the prospect of the latter than the former. With the reluctant help of his stripper girlfriend Cathy (Constance Towers, who'd go on to play the lead in Naked Kiss), he concocts a story about an obsessively incestuous infatuation with his sister's braided hair (Cathy pretending to be the concerned sister), which is enough to get him sectioned and left to roam among the people who he thinks holds the secret of the mystery.

But the more he delves into the lives of his fellow inmates, the film becomes less of a detective thriller and more of an allegorical portrait of America as a giant mental hospital (this predates even the novel of One Flew Over the Cuckoo's Nest by several years), obsessed with past glories (the Civil War), racism, communism, the Bomb, you name it, a world where men claim to be pregnant, black people don KKK hoods and nuclear physicists regress back to early childhood. As the film progresses, it becomes increasingly clear that Johnny's quest isn't so much to find out the killer's identity but an attempt to make sense of American society, though the more he finds out about it, the more his own sanity is placed at risk.

What gives Shock Corridor and Naked Kiss their visual distinction is cinematography by the great Stanley Cortez, whose CV also includes Orson Welles' The Magnificent Ambersons and Charles Laughton's Night of the Hunter, two of the most extraordinarily atmospheric black-and-white films ever made. His work for Fuller isn't quite as memorable, but there's no doubt of the talent behind the camera, with the high-contrast lighting and almost Expressionist shadows perfectly suiting the material - there are also some very effective dream sequences, notably an indoor thunderstorm that perfectly encapsulates Johnny's disintegrating mental state.

But it's Fuller's film first and foremost - "written, produced and directed by Samuel Fuller" almost leaps out of the screen at the start - and probably the definitive example of his peculiar genius. You might not quite believe what you're seeing at times (aside from the nympho ward scene, there's a sublimely tasteless piece of electro-convulsive therapy intercut with and superimposed over a striptease routine), but there's no denying the overall conviction - or the force with which the America-as-asylum message is rammed home.

Despite the Criterion logo, this isn't as impressive a DVD as it could have been. Unfortunately, it was made at a time when the company was pursuing a bizarre policy of not releasing anamorphic DVDs, and although the transfer (framed at the correct 1.85:1 ratio) is sourced from an excellent print (there are only a tiny number of age-related spots and scratches that are easy to ignore), there's an inevitable lack of fine detail and the high-contrast lighting produces more than a few tell-tale jagged edges that betray the lack of resolution. It's certainly a competent transfer, but there's definite room for improvement.

One point that should be borne in mind is that there are two brief colour sequences based on footage shot by Fuller in Cinemascope some years earlier. Every cinema print I've seen of the film showed the footage without anamorphic processing, which helped intensify its hallucinatory quality - and while it's certainly possible to adjust a widescreen TV so that the shots can be seen in their original 2.35:1 aspect ratio, the fact that they appear distorted in is not Criterion's fault.

The sound is the original mono and based a decidedly low-budget original. It's probably as good as you're ever likely to get… but that's not saying very much: dialogue comes across loud and clear, but the mix isn't particularly subtle (then again, with this film, that's hardly surprising!). There are 25 chapter stops, which is more than enough.

This is one of Criterion's less elaborate releases, and only comes with two extras, just one of which is on the DVD itself. I thoroughly recommend the spectacularly lurid trailer, which gives you a perfect taster of Fuller's in-your-face style (it gives very little of the plot away so it's worth watching in advance), while the DVD case contains a pull-out essay by River's Edge director Tim Hunter. And that's it - but in compensation the price is lower than normal for a Criterion disc, and apart from the lack of an anamorphic transfer it otherwise does a very good job of presenting Fuller's demented masterpiece for a new generation. He's one of the cinema's great originals, and Shock Corridor is as good a place to start exploring his work as any.

Michael Brooke