Brain continually rewrites our memories
Researchers from Northwestern University's Feinberg School of Medicine say that memories are continually adapting to our changing environments to help us survive and deal with what’s important in the present. For instance, the scientists believe even people’s recollections of love at first sight could be just tricks of memory, that we may simply be projecting our current feelings on to the memory of the first time we met our partner.
The team recruited 17 men and women to carry out a three-part experiment involving looking at and moving objects around on a computer screen. The participants undertook the tests while in an MRI scanner so the researchers could monitor their brain activity.
In the first part of the experiment, the participants were invited to study various objects presented to them on the screen. Each object appeared on a different background, such as an ocean scene, or an aerial view of farmland. In the next part of the experiment, the participants were presented with the objects again, but on a different background. The researchers asked them to put the objects in their correct locations, as presented to them in the first part of the experiment.
At this stage, the participants almost always put the objects in the wrong place on the screen. Then in the final stage of the experiment, the participants were presented with each object again, on its original background, but in three positions on the screen: the original one, the one they placed it in during the second part of the experiment, and a new location. They were asked to select the position at which the object appeared when they first saw it. The participants kept choosing the position they picked in the second phase of the experiment.
The researchers believe these results show that their original memory of the location had changed to reflect the location they recalled on the new background screen--in short, that their memory had been updated by the insertion of the new information into the old memory.
This is believed to be the first study to show how memory inserts things from the present into recollections of the past. The researchers believe these results could have implications for the reliability of eyewitness testimony in court cases.