Memory is made of this.

Could brain scans one day be used to verify an eyewitness account? Steve Dow reports:

In future, science may be able to distinguish between true and false memories. Brain imaging during police questioning or legal cross-examination could determine if, say, you're a reliable eyewitness.
Daniel Schacter, a Harvard University psychologist, will tell the International Conference on Memory in Sydney starting this Sunday of the "sensory signature" his team has identified through brain imaging and memory tests - a scientific marker that could potentially sort the true recollection from the false...

http://www.smh.com.au/news/mind-matters