At the 2012 International Congress of Psychology meeting in Cape Town, I enjoyed a wonderful talk by Elizabeth Loftus, which offered a terrific demo of how memory works. Loftus showed us a handful of individual faces that we were later to identify, as if in a police line-up. Later, she showed us some pairs of faces, one seen earlier and one not, and asked us which one we had seen. In the midst of these, she slipped in a pair of faces that included two new faces, one of which was rather like an earlier seen face.
Most of us understandably but wrongly identified this face as previously seen. To climax the demonstration, when she showed us the originally seen face and the previously chosen wrong face, most of us (me, too) picked the wrong face! As a result of our memory reconsolidation, we—an audience of psychologists who should have known better—had replaced the original memory with a false memory.