Subliminal ads 'shown to work'

Scientists at University College London said they have brain-scan evidence that the human brain "logs" images whether people are aware of seeing them or not.

The discovery suggests that subliminal advertising has a basis in medical fact. It follows experiments in which a UCL team conducted experiments on seven subjects wearing specially fitted glasses.

One lens was shown faint pictures of familiar household objects - for an example and iron and tweezers - while the other lens was subjected to flashing lights which cancelled out any awareness of what viewers were seeing.

However, the UCL experiment found that the images of objects were being registered in the primary visual cortex, the part of the brain which interprets what the eyes see.

While the experimental subjects could not recall anything they had seen, parts of the visual cortex "lit up" as the household items were displayed.

Dr Bahador Bahrami, of the UCL Institute of Cognitive Neuroscience said: "What's interesting here is that your brain does log things that you aren't even aware of and can't ever become aware of."

People taking part in the experiment were asked to perform either easy or difficult tasks while wearing the glasses.

The researchers concluded that the more distracted the subject, the less likely their brain was to register subliminally flashed images.

In other words, armchair viewers who were slouched before the television set with no other stimuli were most likely to be influenced.