From
http://www.metro.co.uk/news/article.html?in_article_id=142594&in_page_id=34
"You might think you just decided to read this story on a passing whim - but
your brain actually decided to do it up to ten seconds ago, a new study
claims.
In tests, researchers tracked people's thoughts by using a brain scan called
functional magnetic resonance imaging.
Each volunteer was then asked to view a screen and decide which of two
buttons to press and when to press it.
Neural activity in parts of the brain called the prefrontal and parietal
cortex showed people made decisions long before they carried them out.
Prof John-Dylan Haynes, who lead the research in Leipzig, Germany, said: 'We
found the outcome of a decision can be encoded in brain activity up to ten
seconds before it enters awareness. This delay presumably reflects the
operation of a network of high-level control areas that begin to prepare an
upcoming decision long before it enters awareness.'
He added: 'The impression that we are able to freely choose between
different possible courses of action is fundamental to our mental life.
