Can people be influenced by subliminal messages?

The furore over an alleged subconscious message used in TV advertising by the Republican Party in the 2000 Presidential campaign – the word “RATS” flashed quickly on screen while criticising the healthcare policies of Al Gore – was the latest in a series of controversies concerning subliminal advertising.

James Vicary, was a market researcher who famously claimed in 1957 that he could get cinema goers to buy food or drink without them realising, by quickly flashing messages such as “eat popcorn” or “drink Coca Cola” on screen. This February, casinos were forced to remove slot machines in Ontario, Canada after winning images, thought to incite players to continue gambling, were discovered appearing for a fifth of a second on the video screen

The use of subliminal messages is banned in most countries. In the US, the Federal Communications Commission banned the use of “deceptive” subliminal messages in 1974, after the phrase "get it” was found repeatedly flashing during a TV toy advert. The UK Office of Communications maintains that broadcasters must not use messages to influence viewers without them being “fully aware of what has occurred."

These strict regulations are met with scepticism by scientists. “There is no evidence that there is a problem,” says Richard Tunney, Associate Professor of Psychology at the University of Nottingham. “I don’t believe that the architecture of the human mind is such that it could be influenced in this way.” So with this lack of evidence, is there any need for hysteria over the use of subliminal advertising?