7.10 Research on Implanting & Restoring Memories
You and your sibling are fighting over a shared memory. You mention how funny it was when Grandma climbed a tree. At first, your sibling doesn’t remember this happening at all but then another memory of the cousins laughing triggers the tree incident. Then your sibling says, Oh, now I remember, but it was Grandpa, not Grandma that climbed the tree. The fight continues.
Two important things are happening here. It appears that a memory was restored when your sibling suddenly remembered the event. However, the discrepancy in the two memories (was it Grandma or Grandpa) reveals that one of you has an incorrect memory which could possibly have been implanted.
This lesson reviews the current research in memory restoration and implantation. Come along and let’s discover why you and your sibling are struggling to connect over a shared memory.
Memory restoration, the retrieval of previously lost memories can be viewed from two perspectives: general recall restoration and repressed memory restoration.
Memories are formed by connections in the brain. Scientists have actually been able to find and photograph memory engram cells, a physical representation of a memory in the hippocampal dentate gyrus, the input part of the brain responsible for learning and memory. Memory engram cells have tentacle-like appendages that quite literally attach to the brain. It is the strength of these attachments that allow for memory recall. When these attachments begin to fade, recall for the memory becomes difficult. Some scientists claim that there is no such thing as true forgetting, a memory disappearing from the brain; just retrieval difficulties blocking recall.
Some reasons for memory retrieval issues are lack of use of a memory and brain trauma. Simple reminders can help to reconnect memories that are difficult to restore due to lack of use. Think of it as a road. If there had been a mudslide and a small road is destroyed, any town at the end of that road will be unreachable. However, if other roads are built to the town around the damage, then the town is once again accessible.
Alzheimer’s disease is a neurodegenerative disease that has memory loss as a common symptom. Research on mice has led doctors to believe that they could use blue light within the brain, called optogenetics, to trigger lost memories of Alzheimer’s patients and effectively restore many of their lost memories. This type of procedure may eventually be able to work for people with amnesia as well, though further researches are needed.
Repressed memories refer to subconscious memories blocked in order protect you from the mental trauma of the memory.
The idea of repressed memories, especially those related to early childhood sexual abuse, has been a hot topic in the court system for years. While some psychologists feel that repressed memories are restorable through intense therapy, others state that there is a lack of scientific credibility to support the process described in these therapeutic memory restoration sessions. These scientists feel that ‘restored’ memories in these scenarios are actually false memories implanted due to the process of the therapy.
So, we’ve seen that in some cases, memory restoration does seem scientifically plausible and in others not so. What about the second half of your argument with your sibling? Can a memory be changed or implanted?
The short answer to this is, yes. Gestalt principles show how our perception of the world is altered by the way we see things and not just what we see. Psychologists found that what we record in memory is an assumed compilation of the environment and not exactly what was perceived.
For example, in your sibling fight, would it be more likely for Grandma or Grandpa to go up to the tree? Your memory may have filled in the blank for you after a simple glance made you aware that someone older was up on the tree. Your mind would have chosen what seemed more logical and inserted that information into memory.
Memory implantation, when false or inaccurate memories take hold and are believed to be true, can have serious consequences in our legal system that puts a heavy weight on eyewitness identification. A U.S. organization called the Innocence Project details ways in which memories can be altered forever in legal situations. Two of these are:
- Show-up effect in which a suspect is shown to a witness in the midst of a crime scene, thus connecting the person (innocent or not) to the crime in the witness’s memory.
- Memory revision in which witnesses change their descriptions about what they saw after hearing about or seeing a suspect identified by authorities to match that suspect.
Human memory can be manipulated by such simple things as suggestions. This is why repressed memory recovery is so controversial. It would be an easy task to accidentally suggest to a person that they had been abused and were intentionally trying to avoid the memory. Over hours and hours of being told this message, the person’s mind may actually create a fabricated memory to match what is being said.
A less severe case of this is a beloved family story that has been told over and over again, but changes with each telling. Over time, those hearing the story will remember what was told in the story rather than the actual event. This is another possible explanation for the discrepancy between yours and your sibling’s memory from before.
The human memory is more comparable to a sponge in a container than a steel trap. While memories cannot disappear (be forgotten), you can lose the ability to retrieve them. Memory restoration occurs when new pathways are used to cue faded memories. Scientists are also working on methods to trigger memories through optogenetics which could help Alzheimer’s and amnesia patients.
Memory implantation can occur easily through suggestion and/or sensory perception encoding errors. The brain does not work like a camera and memories are often altered without our being aware of this fact.