A biopsychologist explains forgetting – and why it's so useful


Mr. Güntürkün, have you already forgotten something today?

Yes, of course, unfortunately a lot. For example, I could not spontaneously tell you what I was working on today between nine and ten o'clock, without reconstructing it on the basis of many other details. I also remember that my wife was wearing jeans this morning, and when I tell you this, it occurs to me that yesterday it was a skirt. But – I can never say that to my wife – I forgot what the skirt looked like. That may seem rude, but honestly we have to be glad that we can forget.

Why should we be grateful for our miserable memory?

Because the amount of information flowing into us every second is beyond anything our brain can handle. Most of what we see, hear, feel, rushes through our brains, leaving no trace. It is filtered out immediately. We can call that fact oblivious, but actually the information has never been deeply processed. What we call memory is the result of many filtering processes and then goes into the usual signs of wear and tear.

Most people are annoyed when they have a melody in their head and can not remember the song title when they meet a friend, but they just can not remember the name. Would you tell them, “Relax, no problem?”

No, forgetting, of course, can be an incredibly annoying thing. For example, in the past I was able to hear lectures and still understand the contents relatively well after ten years. Today I have to have a notebook with me and write, otherwise the new knowledge is quickly gone. That annoys me. It is so impractical how to wear glasses. And then something else is added: Who would not be afraid of becoming a dementi? It is one of the primeval fears of modern man. Remembering nothing is a terrible condition.

When we talk about memory, we often use metaphors like hard disk, archive, library. Behind it is the idea that memory is a place where you can put something away forever, and remembering means finding your way to that place. Are these pictures obsolete?

They are misguided in that they suggest immutability and stability. That's wrong. The brain is not a computer, but a living organ and subjected to constant processes of change. Every time we recall a memory, she is in danger. Because the moment we activate it, it is flexible. Plastic. Malleable. And we are ready to change it. De facto even delete. Forgetting is an almost more powerful process than learning, and that's why I find it so exciting. He scares us when he gets sick, but at the same time his usefulness is often ignored at all.

Preparations of pigeon brains

How densely packed are nerve cells? Where is something going on when? Research needs animal models like these pigeon brains.

When everything in the brain is constantly in motion, how do we even form a clear idea?

Among other things, by deleting certain memory contents. This is important to build so-called principle or categorical memories. For example, thinking about your mother, your first boyfriend, your first friend, or your living room, you are creating basic memories, categories. You do not save the tiny daily variations on your mother's face, not even the light that falls into your living room every day, or the armchair that is never exactly in the same place – all that will not remain in your memory, but the one principle reminder is permanently updated. Without forming categories, we would drown in a flood of deja vus. We would constantly see our sofa in the living room by day and would say, ah, I've seen this sofa before.

On the other hand, can we add details to our memories that never really happened?

In everyday life, this happens frequently. Just think of the way old people talk about their childhood. The number of great childhoods is, if you believe them, inflationary. They were always wiser and more diligent in their memory than the boys today and have always known everything. Somehow there is something wrong. We enrich memories with our current knowledge. This happens without evil will.

So we are masters of self-deception?

We only have interpreted memories of our lives and are ready to make some things beautiful. Do you remember, for example, what you thought about the GDR and the Wall in the mid-80s?

On styrofoam heads dry electrodes that are used for EEG measurements

On styrofoam heads dry electrodes that are used for EEG measurements

I thought the German division is normal and will always exist.

That's what happened to the vast majority of Germans. You have seen the division and the wall as something that will not change in your life. Most of them thought: I'm going to die, but the wall will still be there. This knowledge about the wall is coded in various neural circuits, the barbed wire, the watchtowers, the feelings we associate with all of this. If you remember the Wall today, these old neural connections are flexible again. At the same time, another network of neurons is active, the one in which you have stored your new knowledge – the wall is gone. Both circuits are active at the same time. Then a synaptic connection between them can establish. They think that the wall has disappeared and you remember their disappearance. The combination of current and old knowledge is active at the same time and forms a new trace of memory, which complements or replaces the old track. Thus, the old memory is saved again, in such a way that it is a bit extended to this new. And in five years you will be one of the people in Germany who say: “I knew it then: the wall does not last forever, when I told my friend Cem, and he declared me crazy.”

If our brain is so prone to whispering and manipulation, is it possible to differentiate between false and true memories?

Yes, in principle already. But we need to raise awareness of how fragile memories are. If we better understand these mechanisms of remembering and forgetting, we are less vulnerable. We know that people can be persuaded of false memories, such as crime. These acts are then in the brain, they are represented by neurons. The catastrophic thing about such “false memories” is that innocent people can go to jail because witnesses report things that never happened. Without the witnesses lying willingly.

On the other hand, victims are quickly assumed to be faking and fantasizing about an act. Is there a way out?

Police work has improved since the big debates about “false memories”. You can not solve the problem, but make it smaller.

If our brain is so good at forgetting, can we use that to purposely eradicate fears or distressing thoughts?

This is done in clinical psychology. Suppose you were attacked on the way to work, you got away with life, but now you are afraid that this will happen to you again. They try to avoid the memory. They take a different route. But you pass a corner similar to the one where this guy attacked you. At some point, you will not go any further, you will do your home office. At some point you are afraid to go out on the street. At some point, your life is only dark. We need to find a way to bring your memory under control.

By forgetting?

In classical confrontation therapy, one tries to get patients to walk this path until they are no longer afraid. Their expectation – I'm being attacked here – turns out to be wrong again and again, and because of this experience, the brain builds. The anxiety generating neurons are inhibited. The fear is still somewhere in the brain, but it is decoupled, they no longer feel it.

Such therapy usually takes time. Could it one day be a pill to forget, and the fear is gone in an hour?

Medicines alone bring almost nothing. However, I believe that the combination of behavioral therapy and psychotropic drugs can improve the success of treatments in the future. But these psychotropic drugs must be very targeted. The therapist may recall certain memories to the patient. If he then knows which neuron groups are involved and with which pharmacological agent he can address their mutability, then he increases the chance that psychotherapy works better and faster.

That sounds like science fiction. And would it even be desirable? We would start fiddling with people's brains.

We could help millions of people. Our brain is a thought machine, all thinking is based on the associations that we have acquired in the course of our lives. Also fears. When I understand these associations both neurobiologically and psychologically, and then the power for a new way of approaching arises from this combination, that gives me hope. Even pain patients could help you so much better. There is also the fear of pain.

You came as a child from Turkey to Germany, so that your polio disease could be treated with new methods. What is your first memory of Germany?

I remember exactly what the first sentences were that I heard in German. When my father told my sister and me that we were moving to Germany, she asked, “But how is that supposed to work, they do not speak Turkish at all, how does that other language sound?” And my father began to sing: “The thoughts are free”. He had learned German at the Gymnasium in Izmir, and he remembered this folk song. That was wonderful. You can not start a language better.

As a brain researcher, would you agree with the poet of the folk song? Are the thoughts really free?

Of course not. But we humans are not as unfree as some of my neuroscientific colleagues think. In freedom, we always think of either ultimate freedom or complete slavery, in which my thoughts are predetermined. Neither one nor the other applies in my view. I can not be completely free because my brain is already genetically wired so that there are certain ways of thinking and willing that are prototypical to us humans. Tastes are not free. I'm innate that I find sugar good. Unfortunately, I'm also innate that I like fat. If we were ultimately free, there would be no overweight person. There would not be the problem of the inner pig dog before the sport. That means we are not completely free. We are a biological body possessing a highly intelligent biological organ called a brain.

Where is freedom left?

Our thinking can never be completely predetermined because nerve cells that are involved in an active neural network are not strictly deterministic. In addition, the brain is a learning machine. She starts to learn even before I was born. It absorbs environmental behavioral parameters that cause people to do things that are biological nonsense, such as being celibate. We have to deal with the difficult situation that we are not free, but not unfree. In between, we move somewhere. In this gray area, our life takes place.

About: Onur Güntürkün, 60, was born in Izmir and came as a child with his family to Germany to treat his polio disease. The psychologist is particularly interested in the neurobiological foundations of behavior. He researched in Paris, San Diego and Izmir, is a member of the National Academy of Sciences, Leibniz Prize winner and heads the Institute for Cognitive Neuroscience of the Ruhr University Bochum. Since 2017 he is also the spokesman of the special research area “extinction learning”, where it is about unlearning and relearning.


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