A behind-the-scenes doc on the disc describes how director David Cronenberg's crew had tried several methods to achieve a realistic scene, but it wasn't until someone angled a shotgun loaded with rock salt behind the head prosthesis (packed with junk food) to get the dramatic splatter that made the final cut.
NOTE: Tedious plot summary ahead
SCANNERS uses the familiar theme of telepathy to propel its story of a drifter named Cameron Vale (Stephen Lack) who is discovered to be a "scanner" - not merely someone who can read minds and hear thoughts but also to have control over the functions of their organs. Think cardiac. The ConSec organization is working with scanners and even has one on staff (Louis Del Grande) who, during an attempted demonstration of the process, loses his head in that disgusting way after he learns way too late that his volunteer is a powerful scanner called Daryl Revok (Michael Ironside).
Dr. Paul Ruth (Patrick McGoohan) is ConSec's head research scientist who recruits Vale to find Revok, believed to be the leader of an underground group of scanners. Vale connects with others of his kind, most of whom are violently dispatched by Revok's unwitting, otherwise innocent scanned victims who brandish firearms.
Kim Obrist (Jennifer O'Neill) is the anti-Revok, the leader of a group of "good" scanners. She and Vale learn of Revok's ties to a pharamaceutical company called Biocarbon Amalgamate, producer of Ephemrol, an injectable that can quiet those multiple voices in a scanner's brain. They also learn how Dr. Ruth (stop laughing) is connected to all this. A gory showdown between Vale and Revok closes the movie - a bravura meltdown (in every possible sense of the word) with impressive makeup work by Dick Smith.
Like most Cronenberg films, SCANNERS maintains a chilly tone throughout, a straight faced narrative filled with scientific jargon and a fascination with anatomy and physiology. There is a reason why his early films (aside from FAST COMANY, a race car drama) are termed "body horror". Many of the director's other features have sexual preoccupations, but SCANNERS sports no phallic or invaginated portals or discomforting gynecology. Rather, the neurological bases are most essential to this plot, and how the nervous system can be controlled. Computer science too, as one sequence has Vale attempting to "scan" a computer's CNS.
SCANNERS plays like standard chase thriller most of the time, with corporate espionage sprinkled throughout. There is nothing especially remarkable about Cronenberg's screenplay, which was still being written as he was filming due to a very rushed schedule, but his tone is so patented, so fascinating, a real piece with his other work. Serious, anti-establishment themes bubble underneath the lurid imagery. The performances range from barely passable to impressive, with Ironside the latter, though we don't see enough of him. The actor gives an interesting look back in the Criterion supplements.
And Criterion did another fine job with this release; never has this low budgeter ever looked so good. They did what they could with the monoaural soundtrack. And those menu graphics! So perfect! Also, observe the cover and insert art....