The last time you looked at your favorite magazine did you see the SEX in the Gilbey's gin ad? Lurking in the ice cubes. And how about the genital symbolism in the cigarette commercials? Or consider a number of innocent, random words which turn up frequently when someone is trying to sell you a car, or a soft drink, or a six-pack of beer: pints, whose, tastes, cult, shot -- in each case by altering just one letter the word is making a direct pitch to your frisky libido. Mr. Key is very serious about his claim that advertisers, packagers and the rest of the Madison Avenue boys panting away in their air-conditioned offices spend thousands, nay millions, each year to assault your unsuspecting psyche with visual and acoustic messages just below the ordinary thresholds of conscious perception. And it works! Key documents his case indignantly with numerous experiments from the psych lab in which subjects reported experiencing feelings of panic, sexual arousal, dread, rejection, etc. Of course we've known ever since Vance Packard wrote The Hidden Persuaders that this sort of mental manipulation is practiced. But Key's careful case studies which range from the cover of Playboy (""70 percent had some obvious representation of mother"") to Colgate-Palmolive may leave you gawking. Very definitely, there's more here than meets the eye.