Subliminal stimuli
A 2012 review of functional magnetic resonance imaging (fMRI) studies showed that subliminal stimuli activate specific regions of the brain despite participants' unawareness,[4] a result corroborated in a meta-analysis from 2023[5] concerning subliminal stimulation in post-traumatic stress disorder (PTSD).
It is suggested, however, that subliminal stimuli can bias acting decisions, including internally and freely generated ones, but, since that effect remains along with the aforementioned intentions and contexts, any impact on the choice of action are not mischievous but rather appropriate and adaptive.
The methodology of the research also varies by the type of subliminal stimulus (auditory or visual) and the dependent variables they measure.
[13][14] Despite its rigorousness, this assessment can be problematic in studies comparing the brain responses to detected versus undetected stimuli, as the resulting differences could be attributed to the act of answering (e.g., pressing a button) rather than to the (un)conscious processing: in these cases, a no-report paradigm could be preferable.
[22][23][24][25] A significant amount of research has been produced throughout the years to demonstrate the effects of subliminal visual stimuli.
Despite the statistical difference, the subliminal messages had less of an impact on judgment than the slide's inherent level of physical attractiveness.
[17] A seminal article published in 1994 found that subliminal phobic pictures elicited specific electrodermal reactions even if not consciously perceived.
[28] This study paved the way to a prolific research field investigating the psychophysiological and behavioral correlates of emotionally-relevant stimuli made subliminal.
[23] This has been proposed to be caused by a little influence of subliminal stimuli on the cognitive circuits that – together with survival ones – contribute to the conscious experience of fear.
[13][30] Spider-fearful and non-fearful undergraduates experienced either a positive, negative, or neutral subliminal priming stimulus followed immediately by a picture of a spider or a snake.
Laboratory research on unconscious perception often employs simple stimuli (e.g., geometric shapes or colors) in which visibility is controlled by visual masking.
The findings indicate that the proportion of electrical skin changes that occurred following subliminal visual stimuli was significantly greater than expected, while the proportion of electrical skin changes that occurred in response to the stimuli which were not reinforced was significantly less.
Non-words created from previously practiced stimuli have a similar effect, even when they are unpronounceable (e.g. made of all consonants).
[32] For example, one study used other speechlike sounds to cover up the target words, and it found evidence of priming in the absence of awareness of the stimuli.
[32] However, the empirical evidence for the assumption of an impact of auditory subliminal stimuli on human behavior remains weak; in an experimental study on the influence of subliminal target words (embedded into a music track) on choice behavior for a drink,[33] authors found no evidence for a manipulative effect.
Rational-emotive therapy significantly improved scores on all dependent measures (cognition, self-concept, self-esteem, anxiety) except behavior.
Results for the subliminal stimulation group were similar to those of the placebo treatment except for a significant self-concept improvement and a decline in self-concept-related irrational cognitions.
The combined treatment yielded results similar to those of rational-emotive therapy, with tentative indications of continued improvement in irrational cognitions and self-concept from posttest to follow-up.
[35] One of Key's most cited studies is a whisky ad in which he found several hidden figures in ice cubes.
[36] However, Cecil Adams characterises Key as "the kind of guy who could find something suggestive in a dial tone", citing an anecdote where Key objected to the use of subliminal sexual imagery in one of his own book covers, mistakenly believing that the publisher must have used an illustrative photo from an advertisement that employed subliminal stimuli.
]showed that the essential thing in the field of media planning is to obtain the greatest possible memory, which implies a conscious perception and not an subconscious one[citation needed].
[41] In a study, researchers made half of the 105 volunteers feel thirsty by giving them food with lots of salt before performing the experiment.
[41] In another study, participant's ratings of thirst were higher after viewing an episode of The Simpsons that contained single frames of the word "thirsty", or of a picture of a Coca-Cola can.
He also suggests that claims about subliminal images are due to the "tendency of chaotic shapes to form patterns vaguely resembling familiar things".
[45] In 2009, the American Psychological Association stated that subliminal stimuli are subordinated to previously structured associative stimuli, and that their only role is to reinforce a certain behavior or a certain previous attitude, without there being conclusive evidence that the stimulus that provokes these behaviors is properly subliminal.
[47] Authors who support this line of reasoning cite findings such as Ronald Millman's research that showed slow-paced music in a supermarket was associated with more sales and customers moving at a slower pace.
Subliminal messaging is prohibited in advertising in the United Kingdom[49] and France,[50] as well as German television and radio.
