Subliminal messages are words, images, or sounds that might appear in television or radio commercials, TV shows or movies, print ads or recorded music. Usually when subliminal messages are seen or heard, they’re not recognized for what they are. In fact, they may be ignored by the conscious brain and be beyond the level of conscious perception.

Before the 1970s, subliminal ads were commonplace in movies and other media.

The theory holds, and it is getting less popular, that subliminal messages are perceived by the subconscious or unconscious mind. Since the conscious mind doesn’t have time to rationalize or analyze these messages, people might more easily accept them. For instance, the use of red in commercials for Target® is at least partly subliminal. The red itself really has nothing to do with the company, but persistence in using it for most commercials means advertisers hope that the color red, whenever seen, will remind people of Target and convince them to shop there.

Subliminal messages might have sexual connotations.

There’s disagreement on the degree to which these messages are used, understood, or accessed. The idea of these messages has been around since the late 19th century, and by the mid 20th century, the use of this messaging in advertising was considered standard fare, especially visual messages where something would flash for a split second on a screen that would subliminally convince the viewer to act in a certain way. People became afraid that subliminal messages could be used to “brainwash” themselves or others. This fear became so great that by the 1970s, the US Federal Communications Commission (FCC) banned the use of subliminal messages in advertisements.

Yet it’s never really been proven these messages work to any great degree. The ban also only exists for advertisement and does not affect film or music recordings. Rock music, especially, came under fire as possibly containing messages of words or phrases recorded backward that people thought were intended to corrupt youth. There have been a few backward-recorded messages in rock music, but not so many as people might think. Further, they may not always have evil intent. There’s no consensus on whether a person could actually perceive such a message, and usually the big thrill is playing the music backward so a backward recording is understood.

Another type of subliminal message that has endured strong criticism is certain animations in Disney® films that spell out specific words. Perhaps the most famous of these is the word, sex, appearing as clouds, in The Lion King. You actually can see this if you pause your DVD player, but Disney did not place it there on purpose. Instead, it’s been attributed to a capricious animator, and would almost certainly have been edited if it was discovered. This also suggests these messages may not work since they may never be consciously perceived. There’s no indication the word sex, which has numerous connotations, could be read or understood by three or four year olds.

Perhaps a more obvious form of subliminal advertising is the idea of hiding things in plain sight, like the use of product placement in films. In several action scenes in the film Spider Man, the action takes place around buildings hung with ads. If you’re conscious of it, you’ll notice the backdrop of ads, but if you don’t realize they are there, they might be considered a form of subliminal advertising. It’s unclear the degree to which these ads might influence buying choice, but they are likely to be taken in by the unconscious mind, while your conscious mind is absorbed by the story action. It can be a matter of how acutely aware you are that product placement exists in many modern films and television series.