American experts suggest that memories linger in ourbraineven when they have already been forgotten. What happens is that we cannot get them back.
Usingadvanced brain imaging techniquesScientists at the University of Califonia Irvine have shown that brain activity when a person remembers an event is similar to that recorded when it was first experienced, even if the details have been “forgotten”. “If the details are still there, maybe we can find a way to access them,” suggests Jeff Johnson, co-author of a study published in the journal.Neuron.
In collaboration with scientists at Princeton University, Johnson and his team analyzed the brain activity of several students who were shown certainwords. Subsequently, they were asked to imagine how an artist would draw the object to which the word gave its name, to think about how the object is used, or to pronounce the word in their mind. Twenty minutes later, the volunteers saw the words a second time and were asked to recall any details related to them while undergoing MRI scans. Finally, using a method of mathematical analysis, the scientists associated the different tasks that had been asked of them with the differentbrain activity patterns. The results showed that when a student retained a strong memory of a word, the pattern was very similar to that generated during the task. And in the same way, when the memory was weak or non-existent, the brain pattern was still recognizable. “This tells us thatthe brain knows what happened, even if the subject is not aware of that informationJohnson concludes.
