Memories that we are not aware of may be just as accurate as those we recall, researchers have found. And they might also provoke unique changes in the brain's electrical activity during recall. The researchers have looked at a type of memory called 'implicit' memory. Whereas 'explicit' memory is full of the things we consciously remember, implicit memory contains memories we do not realize we have formed. The phenomenon has been demonstrated in patients with amnesia, who can, with training, learn to solve specific puzzles more quickly despite insisting that they have never seen the puzzle before.
In a study published in Nature Neuroscience, Joel Voss from the Beckman Institute for Advanced Science and Technology at the University of Illinois, Urbana-Champaign, and Ken Paller of Northwestern University in Evanston, Illinois, report that implicit memory may be at work when we recall images that we have seen before. “What is exciting is they are sort of bringing an experimental lens to the most twilight aspects of our memory,” says neuroscientist John Gabrieli of the Massachusetts Institute of Technology in Cambridge.