“Every time you recall a memory, it becomes sensitive to disruption. Often that is used to incorporate new information into it.” That’s the blunt assessment from one of the world’s leading experts on memory, Dr. Eric Kandel from Columbia University.
And that means our memories are not abstract snapshots stored forever in a bulging file in our mind, but rather, they’re a collection of brain cells — neurons that undergo chemical changes every time they’re engaged.
So when we think about something from the past, the memory is called up like a computer file, reviewed and revised in subtle ways, and then sent back to the brain’s archives, now modified slightly, updated, and changed.
As scientists increasingly understand the biological process of memory, they are also learning how to interrupt it, and that means they might one day be able to ease the pain of past trauma, or alter destructive habits and addictions, as though shaking an Etch A Sketch, erasing the scribbles on the mind, and starting fresh.
“The old view of memory processing was that our memories got stored in the brain and once they’re stored, you can’t touch them,” Nader said. But scientists now realize that memories are evolving all the time. “Every time someone recalls a memory, it’s a chance to change it,” Nader added.
That’s because the memory has to be restored using a biochemical pathway that is very similar to the original storage. And there are ways to interfere with this memory “reconsolidation” using a drug. “You have to change the strength of the connection between neurons. It’s almost like you’ve unwired the memory,” Nader said.
Understanding the neurochemical process of memory opens up possibilities for therapy in situations where memory is causing pain.
Early research on post traumatic stress disorder has been encouraging, Nader said. In studies, subjects have been asked to remember the trauma, and then take a drug that has been shown to block memory reconsolidation, and that seems to reduce the strength of the traumatic memory to non-PTSD levels.
Other research has suggested that it might even be possible to block the memory reconsolidation without drugs, by asking a person to remember something and then, in those moments of remembering, replace the old memory with new information.