This year marks the centenary of Akira Kurosawa. He remains the best-known Japanese film-maker with Western audiences, even though the critical pendulum has recently swung in the direction of Kenji Mizoguchi and Yasujiro Ozu. However, their genius would have gone unnoticed outside Asia for much longer had Kurosawa not won the Golden Lion at the Venice Film Festival with Rashomon (1950), which broke the rules of screen storytelling by confounding the maxim that the camera never lies.

During a downpour in 12th-century Kyoto, commoner Kichijiro Ueda rushes for shelter beneath an ancient gate and overhears woodcutter Takashi Shimura and priest Minoru Chiaki discussing the murder of a samurai. Bandit Toshiro Mifune is suspected of the deed and he testifies that he encountered Masayuki Mori and his wife, Machiko Kyo, and lured the warrior into a forest duel in order to seduce his widow. However, Chiaki contradicts Shimura's version of events by explaining that he met Kyo in a temple and that she claimed to have been mistreated by her loathing spouse and attempted to drown herself after she woke from a faint to find a dagger in his chest.

Medium Fumiko Honma further muddies the waters, however, by insisting he is in touch with Mori's spirit and it reveals that that the samurai committed suicide after Kyo begged Mifune to kill him and run away with her. But Shimura ridicules this variation and avers that he witnessed everything. Repudiating Mifune's boastful heroism, Mori's cuckolded melancholy and Kyo's wronged virtue, Shimura divulges that Mifune begged Kyo's forgiveness after assaulting her, only for her to mock both men as weaklings. Taunted by her scorn, they drew their swords in fear rather than fury and fought inexpertly before Mifune finally prevailed. But Kyo ran away before he could snatch her.

The commoner is convinced that the woodcutter has lied and the priest despairs that nobody can be trusted anymore. However, Shimura demonstrates his good faith by offering to rear a baby that the trio discovers abandoned by its mother, even though he already has six children of his own. Thus, while truth may still be at a premium, there is a shred of decency left in this godforsaken society.

Contemporary critics marvelled at the complexity of the narrative concocted by Kurosawa and Shinobu Hashimoto from two stories by Ryunosuke Akutagawa. But, for all the intricacy of the structure and the audacity of the refusal to tie up the loose ends, the meticulous compositions achieved by Kazuo Miyagawa prowling camera, the tonal shifts created by Fumio Hayasaka's score and the measured pacing of Kurosawa's editing now seem more significant. Even the exceptional performances of Mifune and Kyo pale beside the mastery of Kurosawa's control, as every flourish of macho braggadocio and flicker of scheming contempt seem to have been calculated to fit his grand design to blur the line between myth and memory and prove his contention that `human beings are unable to be honest with themselves about themselves'.

A decade later, another landmark picture with Japanese connections demonstrated Kurosawa's influence on the depiction of time, space, reminiscence and feeling. Hiroshima mon amour (1959) marked Alain Resnais's transition from evocative shorts and he returns this week with his 17th feature, Wild Grass, an adaptation of Christian Gailly's novel L'Incident, which furthers the 87 year-old's fascination with causality and subjective truth.

As dentist Sabine Azéma leaves a Paris boutique after purchasing a pair of expensive shoes, her handbag is snatched by a thief and her discarded purse is discovered in an underground car park by bypasser André Dussollier. Intrigued by the fact that Azéma has a pilot's licence, he decides to contact her about her lost property and daydreams about the ways in which she might express her gratitude. But Azéma restricts herself to curt thanks over the telephone and the disillusioned Dussollier decides to hand the purse to the police.

With Resnais hinting that Dussollier is hiding a guilty secret from his past, the interview with detective Mathieu Amalric goes anything but smoothly. Indeed, he pays him a visit soon afterwards with partner Michel Vuillermoz to caution him after Azéma complains about being stalked. With wife Anne Consigny and children Sara Forestier and Vladimir Consigny unaware of Dussollier's increasingly erratic behaviour, he takes to prowling around Azéma's neighbourhood in the hope of bumping into her (much to the amusement of her colleague, Emmanuelle Devos). Eventually, they agree to meet. But Dussollier's hopes of taking a flight in Azéma's reconditioned combat plane are cruelly thwarted.

Narrated by the unseen Edouard Baer, this compelling picture manages to be both delightful and disconcerting. Born out of both childhood nostalgia and late-life curiosity, Dussollier's fixation feels both melancholic and morbid. Yet, even though it threatens to turn nasty after he vandalises Azéma's car, it remains rooted in courteous curiosity rather than immorality or malice. Ultimately, however, the storyline risks erring too much towards the kind of Hollywood melodrama to which Resnais alludes by having Azéma spy on Dussollier as he leaves a screening of Mark Robson's The Bridges of Toko-Ri (1954) and the denouement that follow will frustrate some as much as it fascinates.

As they seemingly always do, Dussollier and Azéma excel under Resnais's direction. But his choreography of Eric Gautier's roving camera is equally impressive, as is Jacques Saulnier's production design (which drolly contrasts the ditzy spinster's gaudy flat with the family man's stolidly comfortable home) and Mark Snow's score, which teasingly flits between genres with the same finesse with which Resnais references a range of Franco-American screen classics. Very much the work of a master and one who has mellowed without losing his ability to challenge the viewer, this has an elegance and a simplicity that match the deceptive depth suggested in the opening shot of a tuft of grass growing through a crack in the pavement.

The tensions simmering in the tinderbox city of Jaffa are delineated with equally admirable equanimity by Palestinian Scandar Copti and Israeli Yaron Shani in the Oscar-nominated Ajami. The product of several months workshopping with a non-professional cast and shot in a rigorous vérité style, this is a sobering insight into the macho culture that exists on the mean streets of the eponymous multi-ethnic neighbourhood. Moreover, the elliptical temporal structure compels the viewer continually to reassess the ever-shifting situation and gain some idea of the complexity and unpredictability of daily life predicated on hatred, frustration and violence.

Thirteen year-old narrator Fouad Habash is the brother of Shahir Kabaha, the teenage head of his family who is being targeted by a Bedouin gang in a revenge killing. Restaurateur Youssef Sahwani attempts to broker a truce, but the only way Kabaha can pay the agreed fine is by drug dealing. Meanwhile, 16 year-old Ibrahim Frege arrives from Nablus in the hope of finding work to pay for his mother's bone marrow transplant. He is illegally hired by Sahwani, but promptly falls for his Christian daughter, Ranin Karim, who is secretly dating Kabaha.

Completing the story strands are Israeli cop Eran Naim, who is obsessed with tracing his missing soldier brother, and cosmopolitan Arab, Scandar Copti, who has alienated his community by having a Jewish girlfriend and is being investigated by the police for involvement in his brother's drug ring. Indeed, the sins of siblings prove crucial to the combustible action, with confused notions of honour and loyalty further reinforcing entrenched positions. But while the co-directors are to be applauded for the impartiality of their approach, this is often unnecessarily intricate, with the unsigned flashbacks occasionally confusing as much as they illuminate. Moreover, the relentless hustling of Boaz Yehonatan Yacov's handheld imagery tends to disorientate the viewer rather than plunge them into the centre of the action.

The emphasis on the personal rather than the political is laudably shrewd. But the bipartite approach means that Shani and Copti end up compromising rather than critiquing and, thus, while this is technically more ambitious than the majority of films on the Arab-Israeli stand-off, its conclusions are remarkably conventional.

The same cannot be said, on any level, of Harmony Korine's Trash Humpers. Evidently designed to defy explanation, this non-movie has been shot on low-grade videotape to capture the bizarre antics of a trio of miscreants in old-age make-up. Without once making the slightest sense, it is a self-indulgent muddle of sub-standard surrealism and contrived provocation. Yet, not only does it occasionally shock and amuse, but this resolutely non-linear farrago also contains the odd mock-realist image of unexpected poignancy.

Opening with nocturnal shots of Rachel Korine, Brian Kotzur and Travis Nicholson simulating sexual acts with wheelie bins, tree branches and anything else then can frot against, the action follows their perambulations around the seedier parts of Nashville, Tennessee. Having encouraged a podgy schoolboy to beat a doll's skull with a hammer, they seek out a friend who delivers a treatise on the advantages of being without a head. Next, they souse a mess of pancakes in washing-up liquid and force feed them to two blokes joined at the head by a padded pantyhose, who proceed to pay for their supper by giving a sock puppet play about Siamese twins.

Following a spanking encounter with three voluptuous prostitutes (one of whom winds up singing `Silent Night'), the unholy three listen to a beer-bellied bigot recall being trapped in a room with a black man. His tale is topped, however, by a white-bearded fellow in a French maid's uniform, who declaims a disquisition about living in squalor as the trio lets off firecrackers. Having smashed in his head and left him lying in a pool of blood, they then recline on a porch, as a man in a neck brace cracks resoundingly unfunny homophobic jokes. Going inside, they engage in a kinky suffocation game, as an unkempt chap plays electric guitar.

Meanwhile, Harmony Korine, who has been periodically popping in and out of view, drives through the streets and claims he can hear people's pain. However, he decries their insistence on settling for stupid conformity and proceeds to film the threesome dragging dolls across some wasteland behind their bicycles, before closing on a close-up of Rachel cuddling a baby under a street light and the `Three Little Devils' ditty that has been the theme for their mischief suddenly becomes a lullaby.

Wildly esoteric and woefully short on genuinely transgressive wit, this is guaranteed to polarise opinion. Variously recalling Lars von Trier in The Idiots (1998) and TV shows like Jackass, Bo' Selecta, Little Britain and Family Guy, it never remotely approaches the scabrous satire achieved by René Clair and his confrères in Entr'acte (1924), let alone Luis Buñuel and Salvador Dalí in Un Chien andalou (1928) and L'Age d'or (1930). Yet there is more than a hint of mockery at consumerism and bourgeois morality and even if Korine fails to convince that there is a rebellious regressive child in all of us, he still succeeds in pulling off the supreme Dadaist ruse of forcing the viewer to search for meaning in situations that may very well contain none at all.