Our brains update memories when recollections are proven wrong

Researchers from the University of Toronto have confirmed the critical role played by the brain's hippocampus in updating our memories when those recollections are shown to be inaccurate. The hippocampus is part of the brain's limbic system - the amalgam of neurological components that, among other functions, creates and retrieves our memories. Previous research demonstrated that the hippocampus was involved in signaling when reality contradicts our expectations, which researchers refer to as a prediction error. When new information doesn't match what we remember, we sense the signal as surprise - for example, when we hear a friend describe an event we both experienced and discover that some of the details they recall are different from what we remember. But no studies demonstrated conclusively that the hippocampus was involved in subsequently correcting that flawed memory, nor how the revision was made. Now, in a study published this week in the  Proceedings of the National Academy of Sciences  (PNAS), researchers in the department of psychology in the Faculty of Arts & Science are among the first to show that the hippocampus is indeed involved in updating memories and that it does this by switching modes. Alyssa Sinclair - (Photo courtesy of Sinclair) - "What we found is that prediction errors change the role of the hippocampus," explains lead author Alyssa Sinclair, who conducted the research as an undergraduate student in the department of psychology and is now at Duke University. "Surprise disrupts the stability of hippocampal patterns.