Brain waves found that sort real memories from false

From Science Daily:

For the first time, researchers at the University of Pennsylvania are able to pinpoint brain waves that distinguish true from false memories, providing a better understanding of how memory works and creating a new strategy to help epilepsy patients retain cognitive function.

Researchers measured gamma waves and observed the following:

While patients performed the memory game, scientists observed electrical activity in their brains to determine whether specific brain waves were associated with successfully storing and retrieving memories. Researchers found that a fast brain wave, known as the gamma rhythm, increased when participants studied a word that they would later recall. The same gamma waves, whose voltage rises and fall between 50 and 100 times per second, also increased in the half-second prior to participants correctly recalling an item...
Gamma waves actually predicted whether or not an item that was about to be recalled was previously studied, said Michael Kahana, a professor of psychology
in Penns School of Arts and Sciences and lead investigator. In other words, one could see a difference in brain activity just prior to remembering something that had and had not actually happened.

I wonder how useful this could be as a lie detector?
The study will be published in November 2007's journal Psychological Science.