[Paleopsych] BBC: Brain scan 'sees hidden thoughts'
checker at panix.com
Wed Apr 27 01:19:57 UTC 2005
Brain scan 'sees hidden thoughts'
2005/04/25 00:05:47 GMT
Scientists say they can read a person's unconscious thoughts using a
simple brain scan.
Functional MRI scans plot brain activity by looking at brain blood flow
and are already used by researchers.
A team at University College London found with fMRI they could tell what
a person was thinking deep down even when the individual was unaware
The findings, published in Nature Neuroscience, offer exiting new ways
to probe the subconscious, said experts.
In the experiment, Dr Geraint Rees and Dr John-Dylan Haynes measured
brain activity in the visual cortex - the part of the brain that deals
with information sent by the eyes - while volunteers looked at different
test objects on a computer screen.
By looking at the functional magnetic resonance imaging (fMRI) scan
results, the scientists were able to predict what had been displayed on
the computer screen better than volunteers themselves.
When two images were flashed in quick succession, the volunteers only
consciously saw the second one and were unable to make out the first.
But the brain scans clearly distinguished the patterns of brain activity
created by the "invisible" images.
Similarly, a separate study by Japanese researchers, published in the
same journal, found that when people were shown stripes tilted in
different directions, there were subtle differences in the pattern of
brain activity obtained by fMRI.
The scientists built a computer program to recognise these different
patterns and found they could predict what direction stripes had been
shown with remarkable accuracy.
When volunteers were shown a plaid pattern made up of two different sets
of stripes but asked to pay attention to only one set, the program was
able to tell which one the subjects were thinking about.
Dr Rees said: "This is the first basic step to reading somebody's mind.
If our approach could be expanded upon, it might be possible to predict
what someone was thinking or seeing from their brain activity alone."
Dr Adrian Burgess, from the department of cognitive neuropsychology at
Imperial College London, said: "The technique is bringing out
information that has not been available from MRI scans before.
"It could potentially be used to find out people's latent attitudes and
beliefs that they are not aware of.
"You could use it to detect people's prejudices, intuition and things
that are hidden and influence our behaviour."
He said it might be possible to dip into people's repressed memories or
even see people's hidden fears and phobias.
"That's a long way off, but it is exciting."
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