Cognitive Science

Cognitive Science

Thinking can best be understood in terms of representational structures in the mind and computational procedures that operate on those structures

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The Myth of Subliminal Suggestion

Published June 30, 2006 in Alternative Health & Healing 


Subliminal self-help products are widely invested in as useful tools to achieve goals in spite of evidence there are no identifiable effects similar to manufacturer's claims. The present study was consturcted to asses the effectiveness of self-help audicassettes by two modes of presentation. Previous studies on modality effects had observed higher memory and recall in subjects provided with audio stmulus. Subjects were 13 male and 11 female friends and family of the team of experimentors who voluteered thier involvement after giving informed consent. The age range of volunteers was 19-40 (M= 22.5) and randomly divided into four groups, two experimental and two control, testing either audio or visual mode of presentation. Participants had thier memory tested before and after listening to tapes containing self-help message to enhance memory by means of visual or audio presentation. It was predicted that recall would be higher for those participants who listened to memory-enhancing subliminal messages than participants who did not and that recall would also be higher for subjects who listened to a recording of test word lists than those who were presented visually with the same lists. The results indicated that subliminal tapes do not have an effect on increasing memory and recall abilities and that no clear advantages were found in the audio presentation over the visual presentation.

The Effects of Subliminal Suggestion on Memory: Comparing Audio and Visual Presentation

Self-help tapes advertised as containing subliminal messages are marketed as revolutionary aides for achieving goals in health, lifestyle, and education. Over $50 million dollars was spent on subliminal products intended for therapeutic purposes in 1987 by consumers (Eskenazi, Greenwald & Pratkanis, 1994). The debate has been longstanding for years whether or not these recordings actually do as they claim, or if any results, positive or negative, occur at all. Rowe, Russel, and Smouse (1991) asked tape distributors to provide sources that had documented the effects of the subliminal tapes they marketed; they were unable to substatiate their claims with evidence let alone any information having to do with practical application, such as the improvement of memory and recall and whether or not it affected any particular mode of presentation and recall explicitly.

In response to the lack of information circulating on the matter, Rowe et al. (1991) designed a study to review the effects of using a commercially marketed self-help audiocassette containing subliminal messages intended to aid students with achieving academic goals. Their research found that even when exceeding the manufacturer's recommendation of a minimum 25 hours exposure, no evidence of differences was apparent between students receiving the subliminal treatment, and those in a control condition. These results were based on their performance throughout the semester (GPA) and on their final examination scores. In addition, details of spectrographic analysis of marketed tapes was supplied (Rowe et al., 1991), revealing that no evidence had been found of any embedded speech in the background of the recording (as cited in Merikle, 1988). Despite the study having been focussed on whether the tapes had useful effect rather than whether messages were present, it is useful to note that this further unsubstatiates the manufaturers claims.

Eskanazi, Greenwald, Pratkanis, and Spangenberg (1991) performed three replications of a double-blind experiment testing audiocasette products claimed to improve memory and self-esteem. After a month of use, the tapes had not produced the claimed effects; neither self-esteem nor memory improvements could be attributed to the tape. The participants were limited to persons who clearly desired the effects of the tapes. A general improvement for all subjects in memory and self-esteem was obsereved, suggesting that a nonspecific placebo effect had occurred influenced by preconditioning. It was also observed that many subjects believed their abilities had improved in the goal area listed on their tape. However, the lack of significant effect on the participants subject to the subliminal content infers the effect of the tape label on self-perceived improvement had produced an illusory placebo effect.

After completing memory and self-esteem pretests, seventy-eight subjects ranging from 18-60 years participated in a study challenging the effectiveness of commercially produced self-help audiocasettes (Eskanazi, et al., 1994). The findings indicated that the subliminal tapes did not affect any of the paticipants’ performances consistantly as claimed by the manufacturer. These results are congruent to the studies performed by Rowe et al. (1991) and Eskenazi et al. (1991) which reported no significant effects from similar tapes. Furthermore, both Eskanazi (1994) and Eskanazi (1991) offer evidence that supports self-perceived improvement illusions. Subjects who believed they were listening to a memory of self-esteem enhancing audio recording were more likely to claim that they noticed an improvement regardless of whether or not the tape contained subliminal content.

In conjunction with the effectiveness of subliminal self-help tapes, it is relevant to consider the mode of presentation used in the pretesting, and post-testing of subjects in these studies. Eskanazi et al. (1994) performed three timed memory tests involving visual stimulus in both the pretest and postest sessions. In another closely-related study, (Eskanazi et al., 1991) it was not indicated what mode of presentation was used in memory testing. Velayo & Quirk (2000) have performed research that details a higher recall on paired-associates was found for those presented with visual-textual stimulus as opposed to audio stimulus. Studies on short-term memory revealed that recall of auditory items was typically higher than those items presented visually (Godsell & Penney, 1999). With these latter two studies indicating that auditory presentation typically has higher recall, it was reasonable to account that the mode of presentation would affect test results on subjects used for subliminal studies, as there was only evidence of visual stimulus being used for testing. It was curious that no alternate methods of mode were explored in how effective the self-help audiocasettes were on memory, especially considering the materials available that indicated auditory presentation as more effective for recall than visual. While the majority of the research on self-help tapes had supported that the tapes did not aid in recall, it was worth investigating alternate modes of presentation for pretest and post-test sessions to see if there would be any fluctuation in results and subsequently this study was designed to explore that possibility.

The focus of this study was to highlight whether or not these self-help products are beneficial to the consumer, or merely another marketing scam for people who are looking for real help. It is proposed that audio messages below the subjective level of awareness can affect our conscious habit and effort, as well as information percieved above the auditory subjective awareness threshhold. Since this effect has been documented(Godsell & Penny, 1999) it is worth investigating whether or not the two work concurantly.The mode of presentation may play a large factor in the effeticveness of memory and learning techniques when paired with self-help tapes. Studying this possibility may contribute to research in techniques which help people remember more effectively. It was predicted that recall would be higher for those participants who listened to memory enhancing, subliminal messages than those participants who did not and that recall would be higher for participants who listen to a recording of words prior to listening to the subliminal message than those who were visually presented the same list of words.

For details of the methods and graphs detailing the results, please contact the author. They were rather cumbersome to include here and quite dry/academic.

Results and Discussion

The pre- and post- test scores of the experimental conditions were reviewed to assess the effectiveness of the subliminal tapes and the mode in which the tests were administered. Contrary to predictions, those in the subliminal control group did not show any marked improvement. In fact, mean scores were lower after listening to the self-help recording (M= 6.2) than in the pre-test (M= 6.7). Similarly, the theory that audio stimulus may be a more effective mode of presentation for recall in conjunction with self-help tapes is not supported with any data. Scores were higher for the experimental audio condition before the subliminal audiocassette was played (M= 7.95) than the visual condition scores (M= 6.85). The post-test revealed higher scores in the visual control group (M= 7.2) than in the audio group (M= 6.6).

The results of this study imply that listening to memory-enhancing subliminal messages do not improve recall and further solidify claims in previous research by Eskenazi et. Al (1991) that self-help tapes do not produce the claimed effects. Despite supportive research by Godsell & Penney (1999) that infers audio presentation as a more effective mode of presentation, recall was not higher for participants who listened to a recording of the word lists than those who were given the words visually.

While previous findings had shown cases of placebo effect from preconditioning the subjects about what the tape was meant to improve (Eskenazi et al., 1991), no significant assessment of a similar effect can be made here given that few scores in the post-test surpassed those of the pre-test. The random sample of this study is relatively small and probably not an accurate reflection of the population as a whole. Though the study was not intended to assess self-perceived improvement, it can be observed that several participants expressed having feelings that they had done better in the pre-test before hearing the self-help cassettes. Mean scores revealed that many had done better in the first test, a contrast to Eskenazi et al.(1994)'s research which documented a significant degree of self-perceived improvement in those who were aware they were listening to a memory-enhancing recording before taking the tests.

Future prospects for research in this area would be advised to consider testing visual subliminal message as opposed to audio. Given the amount of research debunking the myth of effectiveness for the self-help tapes, perhaps an alternate mode of presentation for below-threshold stimulus may have substantial, noticeable effects. The possibility that visual subliminal suggestion may affect memory could also be tested concurrently with several modes of presentation as performed in this study to maximize the potential for revealing new ways to encourage better recall for participants.

Research on methods for enhancing and developing human memory could have impact on educational and cognitive perspectives, giving psychology a new possibility to help people afflicted with debilitating diseases such as Alzheimer's, which is largely characterized by its effects on memory. Developing new techniques for memory retention would be invaluable to educators and their students, and subsequently increase mental efficiency for those in which such method proved effective. Research on these ideas could potentially save time, health, and money for the average person to the sick or elderly.

Work Cited

Godsell, A. & Penney, C. (1999). Unusual Modality in Less-Skilled Readers. Journal of Experimental Psychology: Learning, Memory, and Cognition, 25(1), 285-289.

Greenwald, A. G., Spangenberg, E. R., Pratkanis, A. R., & Eskenazi, J. (1991).
Double-blind tests of subliminal self-help audiotapes. Psychological Science, 2(2), 119-121.

Pratkanis, A. R. & Eskanazi, J. (1994). What you expect is what you believe (but not
necessarily what you get): A test of the effectiveness of subliminal self-help
audiotapes. Basic and Applied Social Psychology, 15(3), 251-276.

Russel, T. G., Rowe, W. & Smouse, A. D. (1991). Subliminal self-help tapes and
academic achievement: An evaluation. Journal of Counseling & Development, 69,

Velayo, R. S. & Quirk, C. (2000). How do Presentation Modality and Strategy Use Influence Memory for Paired Concepts? Journal of Instructional Psychology, 27(2), 126-133.