Damn, what was the name of that nice man next door? He had such a distinctive smile and held the door open for me. I can’t believe I’ve forgotten his name…. Each of us has had a moment like this in our personal or professional lives. You may remember your neighbor’s name, your coworker’s name, or the place where you misplaced your front door key. But the question in your back pocket is whether this is a harbinger of Alzheimer’s or another dementia-related manifestation.
Before I go any further, let me reassure you: No, just because you can’t remember a name or a place doesn’t mean you have dementia. If you think back to your school days, you were never (or if you were, very rarely) able to recall and actually write down all the material you crammed for an exam. So just because you forget a piece of information doesn’t mean you’re demented.
As a scientist in the field of Alzheimer’s and Parkinson’s research, I know the horror of people forgetting things and losing the ability to organize and manage their daily lives. And I know the fear of those who do not want to end up like those with dementia. But the two are not the same. If we ever forget something, or casually say, “It’s on the tip of my tongue,” it’s usually because that information is so deeply embedded that it can’t get out too quickly via the normal thought and memory cycle wired into the brain.
And as we continue to look at this cycle, we have to say: Forgetting is a gift. With all the concern about becoming pathologically forgetful, we should not lose sight of one thing: ordinary, normal, healthy forgetting is a meaningful, vital mechanism that is the prerequisite for purposeful thinking and human creativity.
It is not for nothing that nature has created two molecular toolboxes, one for remembering and one for forgetting. While the extensions of the branch-like structures of nerve cells, the dendrites, enlarge when new memory content is formed and provide a stronger connection between the neurons at the gap between the communicating nerve cells, the synapses, a reverse process takes place during forgetting: the extensions of the dendrites shrink. This happens in several areas of the brain, including the hippocampus, the site of memory formation, as well as the neocortex and other neural networks.
What happens there keeps both our thinking and our behavior flexible. Ongoing changes to our existing memory content are important so that we can adapt quickly to changing environments. The remodeling work in the brain that causes active forgetting and the building of new memory content must be in balance. We need to think of this flexibility as if a sculptor creating a marble statue were working primarily with the chisel responsible for forgetting.
This may sound a bit painful in terms of the human mind. But for more than a few people who suffer from a disorder on the autism spectrum, the pain is actually caused by the fact that their “memorized” memory is not being worked on with the sculptor’s chisel. Because they are particularly good at remembering minute details, some of them can become upset even if the books on a shelf are slightly different than they were before, or if the table is set with different dishes, or if their parents don’t take them to school in the usual way.
The genetic network that is often altered in autism spectrum disorders blocks the molecular pathway that promotes forgetting, he said. As nice as it is to have a good memory: A brain with a memory that forgets nothing would be optimal at best in a world that does not change. And it would have to be a world in which people did not do bad things to each other. After all, people who cannot forget suffering can, at worst, develop post-traumatic stress disorder (PTSD), the symptoms of which include being inundated with tormenting memories.
The emotional memory of negative events, which causes fears to surface again and again, is accompanied in the brain by increased activity of the amygdala, a paired structure of the limbic system. It is not only after serious, life-threatening crises that the amygdala works at full speed again and again, but sometimes also in the everyday life of a couple. I know from couples therapists that even happy couples sometimes need a pill to help them forget. For this form of forgetting frees our minds and paves the way for forgiveness.
For people with a particularly precise autobiographical, episodic memory, this letting go is difficult. American Jill Price is a woman who cannot forget. With this title of her autobiography, published in 2009, she describes as an inability what others would consider a great talent. Her photographic memory developed when she was in elementary school; as if in a movie, she repeatedly sees entire days of her life in front of her with the utmost precision. She describes it as torture.
People with extremely good biographical memory are condemned to live excessively in the past and not get away from it; they often spend a lot of time with recurring stressful memories. That is, it is important that we also forget. This is good in the first place, because it makes it easier for us to focus on the tasks of life at hand: after all, we can’t do both at once: either we remember, or we are in the here and now.
Another pitfall of supposedly accurate biographical memory is that small changes creep in every time we recall past experiences. The stories of emotionally significant events that we remember particularly well are therefore subject to particularly strong changes over time. In this way, we can also embellish our own life stories. However, when we envy others for their “good memory,” we’re often not talking about their accurate recall of details from their own lives, but their ability to remember facts – in other words, their semantic memory. And it makes us worry that this kind of memory might deteriorate over the years. There are people who worry a lot about this, and others who worry a little.
In everyday clinical practice, standardized neuropsychological tests and, in some cases, imaging techniques are used to determine whether someone actually has mild cognitive impairment or a form of dementia. But first, I ask everyday, seemingly banal questions, Finke emphasizes. For example, is the patient getting enough sleep? Sleep relieves and cleans the brain, making the cortex ready to store new memory content.
Finally, I would like to remind you of a story by the writer Jorge Luis Borges, which illustrates the blessing of the ability to forget through a fictional hero: Here, the brain of this young man loses the ability to forget things and events as a result of a fall from a horse. The result is “The Relentless Memory”. The hero of the story is literally inundated with memories at every appropriate and inappropriate opportunity. It’s excruciating. Worse, because of the intrusiveness of the detailed memory content, he loses the ability to generalize: he can’t see the proverbial forest for the trees of the meticulously remembered. So it is only by forgetting details that we can generalize.