family, science

The Impermanence of Memory

Memories are forever… only they aren’t. There is a reason eyewitness testimony is considered highly unreliable. The processing of memories is a complex thing, and something poorly understood. Most people know there are two kinds of memory, short-term and long-term. What you may not know is that each time you pull up a long-term memory and review it, you alter it. In time, that memory can become false entirely, or falsity papered over reality. This is how memories can be manipulated, with subtle nudges by someone else, on the outside.

There is a kind of memory that doesn’t change, called flash-bulb memory. At a single shocking instant, a memory is seared onto the brain, and these are usually the ones you want to forget and cannot. Usually these are traumatic events, but I find that for me, meeting my children for the first time as they were born are durable memories. Other things I keep tucked away and try not to bump and jar them loose.

So if you alter a memory every time you access it, how can you retain your past with clarity and objectivity? I write things down. I’ve kept journals since I was a young girl, and even though I had to be guarded for years in them, not knowing who else might read them, they are still a tie to the past, one I rarely tug on, but it helps to know they are there. I keep photographs, too, snapshots of that moment in time that bring back a flood of memories related to it when I look at them.

Even worse, by the efforts of someone outside your own mind, you can be induced into remembering things that never happened. False memories, as explained by the Encyclopedia Britannica “some therapists use hypnosis or techniques of “guided imagery” on clients who appear to be suffering from the suppression of memories of emotionally disturbing events, often experienced during childhood. Encouraged to visualize episodes of violence or abuse during therapy, clients may subsequently have difficulty separating these imaginary events from reality. Researchers have found that people who “recover” pseudomemories of trauma are often more suggestible and more prone to dissociate—that is, to feel separated from their actual experiences—than most other people.”

Memory decays, memories can be altered, and in time, you begin to question who you are, and how you came to be who you are. There are methods to preserve memory. Writing down events as they happen, in some detail, is probably the most effective. Memory loss increases with time, and the fine details are the first to go. Methods for self-organization and memory retention range from the journal, to the quirky concept of the memory castle. In this, a memnonic device is created as a mental castle, and you fill the rooms with memories. It’s another way of reviewing one’s memories, and a popular one in fiction. I have never attempted it, and I am not sure it would survive outside fiction as a useful device.

An article in Neuroscience (April 2010) by Fernandez and Kroes, Protecting Endangered Memories, points out “Persistence of memories might then depend on how memories change when new information is learned that overlaps with already existing memories. Consistent with this idea, Kuhl et al.1 found that previously stored memories are reactivated as subjects learn new, overlapping information and that this reactivation protects old memories from vanishing.” The article focuses on their exploration of imaging the hippocampus during activation and storage of memories, and they learned that when new, similar information is learned, it activates and perhaps slightly alters older memories. In this way a web of memories might be creating, connecting the present interactions with family, loved ones, and the past, when similar interactions only dimly remembered, were happening.

This web of memories, locked in our hippocampus, is a safety net to keeping our self-identity intact. When life happens, memories are created, and in time, forgotten, having new experiences that are related to the forgotten ones can bring new life to the old memories. With happy experiences, this can create a balance to go through life contented even when there are storms and tribulations. But when the memories an outside influence focuses on are dark, the self becomes stricken with a snare of doubt, and begins to lose reality in the mist of false memories.