Trevors comments about eye movement during memory recall was taught to me when I was involved in sales. It was explained to me that, when answering a question, if the persons eyes turned up and right they were drawing from factual memory. If, however, the eyes turned up and left they were drawing on the creative side of the brain to invent their answers.
A usual tip to help spot a liar but not a lot of help over the internet and also not really relevent to the topic at hand. Sorry for the diversion! :~)