Wednesday, September 2, 1998 Published at 18:34 GMT 19:34 UK
The Zombie in us all
Zombies were found in graveyards, but they may lurk even nearer home
The idea that your brain sometimes plays tricks on you might not be far wrong.
Scientists believe our minds might be subject to the power of Zombies, a metaphor for the unconscious self which often sees the world in a very different way from the conscious self.
According to the New Scientist, psychologists and neuroscientists are increasingly using the Zombie metaphor to explain our sometimes divided perception of the world.
They say reflex reactions and emotions are the more obvious signs of our split selves, but it is in the field of visual perception that the Zombie comes into its own.
Experiments using optical illusion show that people's unconscious can often detect the illusion although their eye cannot.
He found that, despite attempts to fool the eye about the size of the chips, people still anticipated the real size when they reached out to touch the objects.
Scientists say conscious perception is often slow as it tends to edit and interpret raw data, in contrast to the unconscious.
The Zombie phenomenon could also explain 'blindsight' which allows blind people to accomplish tasks that should require sight.
One man who had part of his sight destroyed after an accident could still perceive wavelengths, shapes and movements.
This suggests visual skills do not all require consciousness.
Research on people who have suffered strokes, tumours or accidents which knock out a part of the conscious brain also shows that there may be another force at work.
For example, some patients lose the ability to recognise faces, but their brain can still show the physical signs of emotion if they are shown photos of their loved ones.
Other research may also offer a scientific explanation for intuition.
Jonathan Schooler, of the University of Pittsburgh Learning and Research Development Center, believes the conscious mind may actually impede lateral or intuitive thinking.
This could be because the conscious mind works at the front of the brain and may close down activity elsewhere whilst lateral thinking works in a more ripple-like way across the brain.
Different modes of functioning
Investigations are also continuing into whether the brain is capable of learning things unconsciously.
Although the thinking on Zombies seems to conjure up 1970s visions of the battle between the left and right side of the brain, scientists say they no longer believe the unconscious is situated in any particular part of the brain.
Guy Claxton of the University of Bristol tells the New Scientist: "It's not as if intuition happens in one place and logical thought happens somewhere else.
"It's that intuition and logical thought are different modes of functioning of the brain as a whole."