"Scanners" derives its cryptically menacing title from a small group of potentially expolsive telepathists.

Recruits in an abandoned experimental program designed to study extasensory perception, these mind-reading, mind-blowing adepts have become a source of alarm to the corporate think tank, ConSec, that nurtured their supernatural faculties.

A murder spree begins with the assassination of a scanner whose brains are literally blown out in the course of a would-be innocuous demonstration at a ConSec seminar. The catastrophe leads project director Dr. Ruth (Patrick McGoohan in scholarly whiskers and a disarmingly subdued mood) to suspect a violent conspiracy masterminded by a scanner renegade -- a former ConSec recruit named Darryl Revok who once tried to commit suicide by drilling a hole through his forehead. In one of writer-director David Cronenberg's niftiest sardonic lines, Dr. Ruth sums Revok up: "At the age of 22 he was self-destructive. At the age of 35 he's simply destructive."

A distinctive new specialist in psychological horror, Cronenberg, a 37-year-old Canadian, gets this tense and unusually brainy chiller -- opening today at area theaters -- off to a spectcular start: Revok, impersonated with admirable tyrannical assuance by Michael Ironside, causes sic inventive homicides. But there's something even scarier about an astutely faked documentary insert, supposedly drawn from the archives of ConSec, which reveals the killer being interviewed by a staff psychiatrist soon after his suicide attempt:

"You wanted to let something out of your head," prompts the interviewer. "What?"

"People," the subject replies ominously. "Too many people. Not enough room for Darrly." Then, as the camera slowly bores in for a closer look, the obscenely grinning young Revok peels off a large bandage to expose the self-inflicted wound in his head. This little black hole suggests truly infinite depths of insanity.

According to Dr. Ruth, there are 236 "known" scanners. He fears that "we've lost them to a program far in advance of our own -- a scanner underground." His desperate method of smoking out Revok is to enlist and train an infiltrator, a derelict young scanner called Vale (the all-too-aptly named Stephen Lack, whose faltering performance places him at a distinct disadvantage during the finale, when Vale must pit himself against Revok in a brain-shattering fight to the finish). Vale is picked up at a shopping mall after impulsively inducing a seizure in a woman who called her companion's attention to his undeniably weird habit of scavenging food scraps.

At first glance, Vale would appear to authenticate the view of scanners expressed by a cynical ConSec official: "You can't get two to sit in a room without going berserk. They're all pathetic social misfits." Under Dr. Ruth's care, however, Vale begins to recover and control his mental processes. Injections of the exotic "scan suppressant" drug, Ephemerol, help to quiet the din of voices in Vale's tormented head. When he demonstrates his ability to accelerate the heartbeat of another control freak, Dr. Ruth sends him into the field in search of Revok.

Vale's mission brings him into contact with the polarized remnants of the scanners. One minor character, a crazed avant-garde sculptor, proves particularly diverting. His grotesque constructions are such overpowering evidence of mental derangement that the funniest line in the script is his blandly cagey remark to the nosy Vale that "My art keeps me sane."

Cronenberg operates within a more sophisticated frame of reference than most scare directors, and he possesses a wickedly humorous ear. For instance, Dr. Ruth's idiom is oddly insinuating: "I want you to slowly release your scan with focus. Remember, telepathy is the direct link-in of two nervous systems separated by space. Now, make your brain make his heart beat faster. . . " It's an elegant blend of the smooth and the sinister, a stylistic blend that Cronenberg also imposes through the imagery and expository tempo.

In his search, Vale encounters a peaceable scanner faction lead by Jennifer O'Neill as a woman named Kim Oberst. As far as Revok is concerned, it's open season on these scanners too. A romantic subplot of some kind appears to be in the cards, but Cronenberg fails to deal the hand. This missing motif is the only glaring inadequacy in his scenario. A persuasive sense of intimacy between Vale and Kim appears to be obligatory and would add significantly to the urgency of the showdown.

Moviegoers who find it difficult to tolerate graphically shocking depictions for any length of time may not be able to take much comfort in Cronenberg's relative restraint. "Scanners" is sustained by a terrifying accumulation of psychological tension, a teeth-gnashing illusion that your mind is susceptible to electrocution at the whim of telepathic despots.

A better rationalized demonic thriller than Brian De Palma's "The Fury," which exploited a similar story premise, "Scanners" makes the idea of mental destruction seem more frightening than the clinically expert spectacle of bulging veins, distorted features and exploding skulls perfected by Dick Smith and the other makeup artists. Devotees of the genre should come out with plenty of sensation to buzz about. Even the squeamish could derive sneaky gratification from a marvelous sequence -- the first of its computer-conscious sort, unless I'm mistaken -- in which Vale endeavors to retrieve classified information telepathically from a data bank. Alerted to his intrusion, a desperate security chief tries to blow Vale's circuits by ordering a purge of the entire computer system. The resulting clash of human and mechanical nervous systems is a catastrophic delight: explosive high comedy of a very rare order. The enjoyment should be enhanced among people adapting to life with computer terminals in their own places of employment.

His earlier horror thrillers ("They Came from Within," "Rabid" and "The Brood") earned Cronenberg a growing cult following. Now "Scanners" begins the new film year on a provocative downbeat and stands a good chance of securing the gifted Cronenberg a place in the mainstream. An authentic, astonishing filmmaking stylist, he approaches the horror genre with complete dedication and an unusually penetrating intellect. "Scanners" is is a pop mindblower conceived by a rremarkably keen cinematic mind.