Experiments on split-brain patients reveal how readily the left brain interpreter can make up stories and beliefs. In one experiment, for example, when the word walk was presented only to the right side of a patient's brain, he got up and started walking. When he was asked why he did this, the left brain (where language is stored and where the word walk was not presented) quickly created a reason for the action: I wanted to go get a Coke.
Michael GazzanigaThe interpretive mechanism of the left celebral hemisphere is always hard at work, seeking the meaning of events. It is constantly looking for order and reason, even when there is none - which leads it continually to make mistakes.
Michael Gazzaniga