The word, 'subliminal' means something that is below the threshold of conscious perception. A subliminal message is embedded in another medium and is intended to be subconsciously perceived by the brain. Subliminal techniques are commonly applied to advertising to convey hidden messages to the masses. Subliminal advertising aims at presenting messages in disguise of normal depictions. The techniques of subliminal advertising inject subliminal signals at the rate that a human eye is unable to detect but the subconscious or the deeper mind senses them. Subliminal signals can influence subsequent thoughts and actions of their receiver. Interestingly, the receiver of these signals is unaware of having seen anything, while the person's actions show an influence of the signals received. This happens because subliminal signals are the subconsciously perceived ones and the conscious self within an individual is unaware of the perception. To a certain extent, the subliminal advertising techniques are based on illusions. The presence of shadows, visual and light effects and the use of depths in the depiction of pictures affects the perception of the dimensions of the image. Owing to the optical mechanism of a human eye, the image falling on the retina is affected by the amount and direction of light present in the picture seen. Light effects can influence the human judgment and comprehension of the image. The presence of such visual effects in a picture, influences the way in which the human eye perceives it. The application of subliminal techniques to the visual media is also seen in products where brand names are embedded in images. Advertisers use techniques wherein an image or a piece of text is flashed in several ways, several times. It may be flashed in fractions of seconds making it apparently invisible. But these images are sensed at a subconscious level. Research has shown subliminal exposure to have a deeper impact on individuals. Some studies have shown that subliminally presented visual have had a greater influence on the target audiences. Subliminal advertising is also applied to the audio medium. Back masking is an audio technique in which sounds are recorded backwards on a track. To the human ear, they are sensed as being unintelligible sounds while the subconscious mind comprehends the messages. The messages are said to be subliminally heard and can induce the listeners to the actions they intend to convey. There was a court case about two young men to have shot themselves under the influence of subliminally conveyed messages by a particular soundtrack. However no scientific evidence of the presence of subliminal messages in the song could be produced. Subliminal messages are believed to affect a person's state of mind and behavior. According to researchers, for subliminal advertising to be effectively communicated, the person watching or listening to the advertisement should do so with a fair amount of concentration. Therapists have claimed to treat psychological problems by means of subliminal audiotapes, but no conclusive results have been brought about as of today. The film and television industry has commonly been using subliminal techniques to fetch mass appeal. The famous film, 'Fight Club' flashed of the image of Tyler Durden in the form of subliminal series of images, before the character was actually introduced in the film. For the US Presidential campaign, a television advertisement had shown the word, 'bureaucrats' in the form of a subliminal image. Some TV serials used to advertise their upcoming episodes by means of subliminal advertising. Formula One racing had once used cars painted such that they appeared to carry messages, which looked like they were made of banned tobacco products. One of the obvious forms of subliminal advertising appeared in the Sprite advertisement, which made a prominent use of the colors yellow and green. The field of advertising uses subliminal techniques to promote products through a communication that can be comprehended at a subconscious level. In many instances, the advertisers embed the logos of their product in their advertisements. They include slogans and promotion messages as a part of their advertisements, in an effort to reach out to the subconscious minds of their audiences. Some have criticized subliminal advertising while others are finding ways to use this technique positively. As subliminal communication is known to be perceived at a subconscious level, subliminal advertising has the potential to be effective in 'publicizing positivism'!