A new kind of brain scan has been developed which can effectively read a person’s mind, according to researchers who have been able to differentiate brain activity liked to memory. Researchers showed guinea pigs three clips from movies and then scanned them to see if they could determine which film each person was thinking about. The scientists from University College London found they could identify thought patterns by using functional magnetic resonance imaging. The evidence suggests researchers can tell which memory of a past event a person is recalling from the pattern of their brain activity. "We've been able to look at brain activity for a specific episodic memory -- to look at actual memory traces," senior author of the study Eleanor Maguire, told Discovery News. "We found that our memories are definitely represented in the hippocampus. Now that we've seen where they are, we have an opportunity to understand how memories are stored and how they may change through time."