Mind alters memories, rewrites past with new information

Love at first sight, or is it just hindsight?
Our memory constantly rewrites our past, updating it with the wisdom of new experiences, a new study has found.
"Your memory is a wily time traveller, plucking fragments of the present and inserting them into the past," scientists said.
Rather, the memory rewrites the past with current information, updating your recollections with new experiences, they said.
Love at first sight, for example, is more likely a trick of your memory than a Hollywood-worthy moment, researchers said.
"When you think back to when you met your current partner, you may recall this feeling of love and euphoria," said lead author Donna Jo Bridge, a postdoctoral fellow in medical social sciences at Northwestern University Feinberg School of Medicine.

"But you may be projecting your current feelings back to the original encounter with this person," Bridge said.

This the first study to show specifically how memory is faulty, and how it can insert things from the present into memories of the past when those memories are retrieved.
The study shows the exact point in time when that incorrectly recalled information gets implanted into an existing memory.
To help us survive, our memories adapt to an ever-changing environment and help us deal with what's important now, Bridge said.
"Our memory is not like a video camera. Your memory re-frames and edits events to create a story to fit your current world. It's built to be current," Bridge said.

All that editing happens in the hippocampus, the study found. The hippocampus, in this function, is the memory's equivalent of a film editor and special effects team.
For the experiment, 17 men and women studied 168 object locations on a computer screen with varied backgrounds such as an underwater ocean scene or aerial view of Midwest farmland.
Next, researchers asked participants to try to place the object in the original location but on a new background screen. Participants would always place the objects in an incorrect location.
Finally, participants were shown the object in three locations on the original screen and asked to choose the correct location. Their choices were: the location they originally saw the object, the location they placed it in part 2 or a brand new location.

"People always chose the location they picked in part 2," Bridge said.
"This shows their original memory of the location has changed to reflect the location they recalled on the new background screen. Their memory has updated the information by inserting the new information into the old memory," Bridge said.
The study was published in the Journal of Neuroscience.