Not exactly the generally accepted definition of "brain food."
Ah, the 1950's. A postwar era of prosperity that promised great leaps in science, accompanied by (if the movies were to be believed, anyway) the opening of a Pandora's box of unspeakable, Lovecraftian, technology-related terrors. The greater majority of films delving into such material tended to be American in origin, but this memorable little shocker hails fro England and once seen, it's impossible to shake.
Mysterious deaths in a Canadian farming community near an American Air Force base leave in their wake corpses missing their brains and spinal cords, but that are otherwise in pristine condition. The military's investigation turns up a retired scientist whose experiments in telekinesis have granted him the ability to successfully project his thoughts, but an unexpected side-effect of all that is the generation of a new, invisible form of self-replicating life, thanks to radiation from the base's nuclear-powered radar experiments (?). These invisible critters feed on the base's radiation and begin a spree of killing anyone who stands in the way of them taking over the reactor. Once the radiation levels are cranked up by a pair of them, the creatures are rendered visible and revealed to be the missing brains/spinal columns, only now mutated to include eye stalks and pseudo-tentacles, with the spinal columns serving as powerful springs to launch them into aerial attack mode. Soon the military and a handful of civilians find themselves trapped in the scientist's home as the abode falls under siege from a legion of the brain monsters and all bets are off, as all hell breaks loose in a splattery orgy of bullets, blood, and gray matter.
FIEND WITHOUT A FACE would be a rather undistinguished half of a double-bill if not for it wielding a decent creep-factor during the creatures' unseen phase, and its unforgettable last fifteen minutes. Once the brains are visible, they fly all over the place in a flurry of stop-motion malevolence that is dealt with by the military with no-holds-barred extreme prejudice. It's so balls-out that it can immediately be cited along with THEM! (1954) as one of the ancestors of the us-against-monster-horde mayhem found in ALIENS (1986). For that reason alone, FIEND WITHOUT A FACE is required viewing for both the casual viewer and the seasoned genre completist.
Poster from the original theatrical release.