What has happened in the area of subliminal influence in the 8 years since we wrote our reviews for Skeptical Inquirer? [See: Moore, T.E. (1992). Subliminal perception: Facts and fallacies. Skeptical Inquirer, 16, 273-281; Pratkanis, A. (1992). The cargo cult science of subliminal persuasion. Skeptical Inquirer,16, 260-272.] In a nutshell, a little bit more science, a little less hysteria, and some still long-term, unresolved issues. 
In the "little bit more" category, recent scientific evidence continues to support our original appraisal that actions, motives, and beliefs are not susceptible to manipulation through the use of briefly (i.e., subliminally) presented messages or directives. If anything the case against subliminal manipulation is stronger now than ever as a result of some recent research designed to address Anthony Greenwald's (1992) "two-word challenge" -- to create an experimental demonstration that multiple words presented subliminally could be understood as a unit and more than the sum of the parts.
Numerous studies had previously demonstrated semantic activation of single words under conditions in which subjects had no phenomenal awareness of the stimulus, as we noted in our reviews. However, no priming study had shown that multiple words, presented subliminally were capable of semantic activation. Such a demonstration would be essential for validating claims that phrases such as "Eat Popcorn/Drink Coke" and "Mommy and I are one" could affect human motivation and behavior. (The latter phrase comes from the work of Lloyd Silverman and the ‘subliminal psychodynamic activation’ paradigm. Silverman had claimed therapeutic effects for his technique; see Silverman & Weinberger, 1985; Weinberger & Hardaway, 1990). If phrases such as "Mommy and I are One", subliminally presented, produce important consequences for the viewer, the entire sentence, including all semantic relations inherent in the sentence's syntactic structure, would have to achieve internal representation.
A recent study by Draine (1997) has cast considerable doubt on the proposition that multiple words presented subliminally can be comprehended. In his work, Draine established that priming effects of word pairs are a function of individual word meanings, rather than their combined meaning. For example, the pair of words "Not Dirty" was perceived to be evaluatively negative. The impact of the prime was uninfluenced by its negation. Draine concluded that two-word grammatical combinations are beyond the analytic powers of unconscious cognition. (see also Greenwald and Liu, 1985).
In the "little less of" category, we are pleased to report that much of the furor over subliminal influence has died down. There have been no new rock bands labeled as "subliminal criminals." In 1991 a suit brought against Ozzie Osbourne in Georgia was dismissed because the judge found no evidence of subliminal material on the record in question. The news media, including ABC, CBS News, and CNN Headline News have made numerous accurate presentations of the scientific data showing the ineffectiveness of subliminal influence in general and subliminal self-help tapes in particular. The National Academy of Science and the British Psychological Association both issued statements concerning the lack of efficacy of subliminal tapes. The level of promotion of subliminal self-help tapes seems to have declined. The message seems to have gotten out that when it comes to subliminal tapes, "Buyer Beware," although sales of such tapes continue.
We wish we could end this update on a happy note and state that the hysterical claims for the power of subliminal influence have finally been laid to rest. However, we noted in our reviews that interest in subliminal influence is often cyclical -- first appearing before the turn of century, then again in the 1950s, 1970s, and today. And while the most recent manifestations of interest in things subliminal appear to have died down, the underlying reasons for this interest remain. These include a general lack of scientific literacy, unclear standards for qualifying experts in court (Moore, 1996), confusing unconscious perceptual processes with the psychodynamic unconscious, a mass media interested in ratings and the sensational, and a desire for quick solutions to difficult problems and quick scapegoats when the quick solutions don't work.
There is also a feature of subliminal stimulation that is somewhat unique compared to other urban myths -- namely that evidence that could disconfirm the presence of subliminal stimuli is not readily available to the viewer (or listener). A subliminal stimulus is, by definition, outside of conscious awareness. Consequently, NOT seeing (or hearing) subliminal messages when one suspects their presence, confirms their presence in the minds of those who have been encouraged to believe in subliminal persuasion. For this reason, subliminal conspiracies will no doubt continue to crop up. Time will tell if, 5 or 10 or 20 years from now, some new researchers will need to write articles similar to the ones we wrote 6 years ago to alert the public to the fact that no scientific evidence is available showing that subliminal stimulation can significantly influence human motivation and behavior.
Draine, S. C. (1997). Analytic limitations of unconscious language processing. Unpublished doctoral dissertation. Department of Psychology, University of Washington, Seattle, WA.
Greenwald, A. G. (1992). New look 3: Unconscious cognition reclaimed. American Psychologist, 47, 766-779.
Greenwald, A. G., & Liu, T. J. (1985, November). Limited unconscious processing of meaning. Paper presented at meetings of the Psychonomic Society, Boston.
Moore, T. E. (1996). Scientific consensus and expert testimony: Lessons from the Judas Priest trial. Skeptical Inquirer, 20(6), 32-38.
Silverman, L. H., & Weinberger, J. (1985). Mommy and I are one: Implications for psychotherapy. American Psychologist, 40(12), 1296-1308.
Weinberger, J., & Hardaway, R. (1990). Separating science from myth in subliminal psychodynamic activation. Clinical Psychology Review, 10, 727-756.
1 Editors Note: There is also an article in the same issue of Skeptical Inquirer on Subliminal tapes by Brady J. Phelps and Mary E. Exum.