Most of us think of memories as something static that we “take out” from time to time. But years of study have shown scientists that memories constantly evolve over time. That can make memory less reliable than you might believe it to be – even to the point that you remember details of something that others say did not happen.
The good news is that this is not necessarily a sign of mild cognitive impairment. Rather, it’s just the way the brain functions. It revolves around a process that experts call memory reconsolidation.
How Memory Reconsolidation Works
Memory consolidation is a process through which memories are made to persist. When you have an experience, it becomes a short term memory stored in the hippocampus. If the memory isn’t consolidated and moved from the hippocampus to other parts of the brain, then long term memory doesn’t occur, according to neuroscientist Joseph E. LeDoux.
Consolidation refers to this conversion of short term memory to long term memory. Neurons in the brain that form the memory undergo protein synthesis. Essentially, the proteins “glue the memory together,” LeDoux said.
Experts now know this is not the end of the process. The next step is memory reconsolidation, which happens every time you retrieve a memory that has been previously consolidated. That memory now must go through another phase of protein synthesis to persist into the future. The brain updates the memory with new information.
For example, the first time you meet someone, you form a memory of that person. When you meet them again later, you retrieve the memory and all the things you’ve learned about the person are incorporated into a new memory. That allows it to persist into the future, but the first memory has been altered. It’s a process of constantly updating.
This may have major implications in therapy. For example, a person who has experienced a traumatic event can visit a therapist and recall that memory by talking about it. However, right after the memory is retrieved, the therapist could give the patient a drug that could block protein synthesis. That could dampen the memories, making them less troubling in the future.
How Your Memory Fools You
While reconsolidation opens possible new therapies for those with troubling memories, people should know outside information can manipulate memories over time.
Elizabeth Loftus, a professor at the University of California Irvine, has proven this time and again. She teaches psychology and law. Her focus has been on studying people who remember things that didn’t happen or remember things differently from the way they occurred.
One method her researchers have used is to show people a simulated crime or accident, then feed them false information when they retrieve the memory. For example, they may see a car run a yield sign, but under suggestion as they recall the memory, some can become convinced they saw a stop sign.
Her research also has included planting entirely false memories into people. For example, her team has successfully convinced people they once got lost at the mail until an elderly person returned them to their parents. People believed in this memory even though it never happened.
She said what studies by her team and others have shown that “memory is malleable. It doesn’t work like a video recording. You don’t just record the event and play it back; the process is much more complex. The take home message from all this is just because someone tells you something with a lot of detail and confidence and emotion, it doesn’t mean it really happened.”
It also doesn’t mean that every slip of memory or having someone correct you one what happened is a sign of cognitive decline. In some cases, it’s simply a consequence of how our brains work.