This used to be discussed on the weird Art Bell Show a long time ago (before Oates and Bell had a major falling out). David Oates who has appeared on Bell's show has for years recorded speeches of famous people and played them backwards, looking for hidden messages that reveal their true selves. His theory is that the subconscious mind doesn't necessarily have a backwards and forwards direction and can reveal itself by existing in backwards language implanted in the choice of forwardly spoken words. I believe Mr. Oates compares it to the subsconcious "Freudian slip" but somewhat more complicated. I don't think there's very much scientific legitimacy to this but it can be fun, especially when studying the supposedly hidden messages in George Bush's words. Oates gives some funny examples below, taken from Bush's Republican convention speech and previous speeches. At the bottom of the page at the link (below) you can click on his link where you can hear George Bush's backwards language:
"...George Bush at The Republican Convention
By David J. Oates
September 2004
The study of Reverse Speech over the years has yielded many insights into the minds of our political leaders. Of no exception to this is United States President, George W. Bush.
In previous articles on this website, we have noted several trends in the reversals of George Bush, such as an edge that is first seen during the 2000 election campaign. As he talked about the murder of a black man, he delivered a reversal that said, "Hide the filthy nigger." This continues throughout his presidency with reversals of contempt against both the Senate and Congress. "Senate, they're all first year losers," and "Choke the fuckers now" when he was talking about Congress.
We have noted that Bush is a strong leader. We see this with reversals after 911 such as. "Sky, see the limit with terror," "I am avowed", and "I must reveal the law." We noted his resolve to move into Iraq as early as 2002 with reversals like "Mess Iraq," "Begin with Iraq," and Kill them with the friendly London. On domestic issues, we have noted that Bush appears to be incongruent with reversals such as "You can't do it," and "Renege on it." as he talked about tax cuts for the middle class, and "We're doubtful we will beat them," as he talked about combating corporate corruption...."
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http://www.reversespeech.com/bushconv.htm