Subliminal Messages Work, at Least Sometimes

Aug. 28, 2008 -- Attempts to manipulate consumers with subliminal messages, flashed onto movie or TV screens, once thrilled advertisers and panicked the public, but the furor faded when the technique failed to work.

But a study published on Thursday has given what is claimed to be the first evidence to the contrary -- that our decisions can, in fact, be influenced by subconsciously perceived cues.

An unusual experiment, recounted in the British-based journal Neuron, could go a long way to explaining the mystery of what is often called intuition, its authors say.

"Humans frequently invoke an argument that their intuition can result in a better decision than conscious reasoning. Such assertions may rely on subconscious associative learning," said lead author Mathias Pessiglione of University College London.

For example, a poker player who somehow always knows when to fold or call a bluff may be picking up on telltale signals from his opponents, using a part of his brain unrelated to conscious thought.

Previous studies have shown that people, like rats or dogs, could be conditioned to respond to unconsciously perceived stimuli. A subliminal image linked to an electrical shock, for example, will -- after repeated jolts -- cause a person's palms to sweat with anticipation.

But these are so-called "automatic" responses that do not involve conscious thought.

The new study is the first to show that such cues can influence deliberate choices too.

In the experiment, 11 men and nine women aged 18 to 39 were repeatedly exposed to one of two symbols sandwiched between a pair of abstract images.