Ice water can rescue lost memories

Some events can change or mark our lives forever. When we suffer some strong experience, the same state of shock that is generated in those moments causes that the memories are embedded in the memory . This means that we can remember the exact moment and what we were doing right at the very moment of the event.

Based on this fact, Argentine scientists from Institute of Physiology, Molecular Biology and Neurosciences (Ifibyne) from the University of Buenos Aires, they discovered that with this same principle it is possible to rescue memories that were thought to be forgotten from the minds of individuals; said study was published in the prestigious scientific journal Neuroscience.

The expert biologists of the Laboratory of Neurobiology of Memory: Veronica Coccoz , Hector Maldonado Y Alejandro Delorenzi , who had already made this discovery in animals and who now confirmed their theory in people, worked with 125 volunteers and they used the intense cold to generate a shock Similar to the one that occurs when there is a strong emotional shock.

Delorenzi he explained to BBC World that in the field of neurobiology It is common to use cold to generate this form of mild but acute stress, which leads the body to release glucose and a series of hormones that are central to the modulation of memory. "It was already known that these substances act in areas of the nervous system. central when memories are consolidated and become strong memories, which will last a long time, "he said. The novelty was to confirm that these same substances can also help to recover forgotten memories.


The experiment

To test this hypothesis, the team of researchers showed the volunteers a series of stimuli : a combination of light , music and images . And, later, they were asked to learn a list of syllables. Six days later, the neurobiologists returned to expose the group to the same stimuli of light and music, but interrupted the experience before showing the images.

In addition, subjects were asked to immerse their arm in a container of water. One group did it in Water tempered , the other half in frozen water . The volunteers were then asked if they remembered the syllables learned six days ago. None remembered them correctly. The next day, the whole group was summoned again and they were shown again the stimulus of light, music and images. Then, they were asked again if they could remember the syllables learned a week before.

Only a minority (20%) of those who had submerged the arm in warm water correctly recalled the list. But the vast majority (80%) of those who had touched the ice water (receiving the shock of stress) remembered the sequence of syllables, which had been forgotten.


A step

The doctor Delorenzi he told BBC World that, in addition to being subjected to a shock, it is necessary that the subjects receive an associated "reminder", in order to remember what was believed forgotten. That is why the stimuli of light, music and images were used. The key, explained the neurobiologist, is that when you want to recover the lost memory an alteration of that reminder is made.

In this case, first a sequence of light, music and images was shown, and, in the second instance, that sequence was interrupted, so that the reminder was different. It is this novelty that makes the memory come true "labile "(a definition used by experts to describe the reactivation of that memory.)" The striking thing is that the subjects claimed to have no more memory of the syllables learned, but in effect that memory had been reactivated, because the next day they were able to remember them. ", he claimed Delorenzi .

For the specialist, this finding could help to unveil some unknowns that are had regarding the memory defects, since it would allow to investigate if the problem is in the "storage" of the memory , or simply in the ability of the subject to "express" that memory - that is, to be aware of having it.

"We believe that this will contribute a lot to the persistence of memory, to be able to remember," said the expert, clarifying - however - that it will remain in the hands of others. Practical applications for the finding. The next step for these scientists is to perform the same experiments but testing longer time extensions.

Source: BBC World