Under normal circumstances, some things are not forgotten in a lifetime. Cycling, swimming, or ice skating are included. On the other hand, memory researchers can explain why the PIN code of the credit card or the name of a long-term classmate suddenly no longer occurs. The answer lies in the question Why don’t we forget how to ride a bike. Let’s take a look.
It’s about two different things that are stored in different places in the brain. Names or numbers that you remember are stored in the so-called fact memory. Memory researchers also refer to the sum of these contents as semantic knowledge. On the other hand, certain events, for example, the memory of the first day of school or the first kiss, are stored in the episodic memory. Both have in common that every healthy person is aware of this memory content. This creates the opportunity to communicate with others. Because of this common ground, they are grouped under the heading of declarative knowledge.
Skills that happen automatically
On the other hand, there are physical skills that have been learned, and that can be practiced automatically. One example of this is cycling, which is often referred to as ineligible. In contrast to declarative knowledge, this special knowledge, also known as procedural knowledge, cannot be accessed consciously. Someone who has cycled long distances through his youth breaks off cycling overnight because he has bought a car. After several years without a bicycle, he is asked whether he can still cycle. However, the questioned person, who is healthy, cannot answer with certainty. The ability to ride a bike would have to be proven in a new attempt and at the beginning, there could be some shaky uncertainties.
Memory researchers are certain that simple sequences of movements that have been learned so well that they can be performed automatically will remain available in the brain for a lifetime. They are mainly stored in the so-called basal ganglia under the cerebral cortex and in the parietal lobes.
Declarative knowledge, on the other hand, can be lost over time. However, the experts are not yet clear about the reasons. One thesis says that in the brain regions in which procedural knowledge is stored, significantly fewer neurons form than in the hippocampus, where declarative knowledge is stored. The constant reconstruction that takes place there through the formation of new nerve cells could lead to the gradual deletion of declarative knowledge, i.e. facts, data, and memories. However, this theory lacks scientific evidence.
Maintaining certain skills until the end of your life only applies to simple movements. Complex sequences, on the other hand, as well as facts or episodes can be forgotten again because nothing else is unlearned. A good example of this is the dance steps. If the basic step has been rehearsed for hours, most of them can reactivate it relatively quickly even after years. All twists, figures, and other finesse, however, seem blown out of the head.