Re: Consciousness and Causality

From: Carless, Rachel (rec195@soton.ac.uk)
Date: Sat May 25 1996 - 16:32:35 BST


DESCRIBE LIBETS FINDINGS ON THE TIMING OF A DECISION TO MOVE

  When Libet was reaserching 'Conscious intentions',
he wanted to try and discover exactly when a mental
intention to carry out an act takes place. He believed that
the only way this could be achieved was through an
experiment which allowed subjects to self time themselves
as they were the only ones who had access to their own
experiences. The subjects were asked to look at a clock and
told to flex their wrists whenever they felt like it whilst
mentally making a note of the position on the clockface at
the onset of the intention. Libet believed he was thus
creating a recording of voluntary , internally generated
actions.
   Libet found that motor potentials occured on average
550 ms before an action took place. He also discovered that
the point at which the subjects recorded conscious
intentions to move occured 200 ms before they did move.
Therefore a difference of about 350 ms took place between
the preparation to act and the conscious intention of
acting. On the basis of this evidence Libet advocates the
idea of free will and us being accountable for our own
actions. This is because of conscious intentions occuring
before movement, thus giving us time to allow us to
consiously permit our own actions.



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