We all know the everyday situation: you go into a supermarket, realise that you’ve left your shopping list at home and, try you as you might, you can only remember a fraction of what was on it. Forgetfulness is seen as a deficit which makes life more complicated. Anyone who is chronically forgetful is quickly seen as being a bit dotty. In the worst case, it is a symptom of illnesses such as dementia. Regardless of whether forgetfulness is interpreted as an indication of human fallibility, as a foible, or turns out to be an illness - the connotations are negative. One project running at the Institute of Psychology in Education shows the issue in a different light. Prof. Stephan Dutke, Dr. Sebastian Scholz and Prof. Niko Busch investigated the phenomenon of so-called intentional forgetting. "In a constantly changing world in which we have to juggle with a lot of information," explains Sebastian Scholz, "intentional forgetting helps a person’s cognitive system to react flexibly." For example, he adds, anyone who receives a new PIN number for their EC card is more likely to enter the new, correct number, if they are able to forget the old one.
It has been known for some time now that the interplay of two mechanisms makes intentional forgetting possible. On the one hand, contents which are to be forgotten are suppressed in order to reduce the probability of their being stored or retrieved. To increase this probability, on the other hand, information which is to be remembered is selectively repeated. "Special areas in the human brain are activated when someone consciously tries to forget a piece of information," says Scholz, who gained his PhD at the University of Münster on subjects relating to remembering and learning. The human brain, he says, appears to possess a mechanism which makes it possible to suppress the formation of memory content and thus increase the probability of forgetting it. "My research showed that successful, intentional forgetting was marked by specific electrophysiological activity in the central and frontal brain structures," he says. As a result, he adds, intentional forgetting is not the simple absence of what has been learnt, but rather a certain cognitive function. "The research findings help in differentiating theories about active and passive forgetting - not only at the level of observable behaviour, but also in respect of measurable brain activities," Stephan Dutke adds.
But why is forgetting important? "People have limited cognitive resources at their disposal. Some theories say that similar contents in the long-term memory compete for identical retrieval stimuli. However, if too much similar information was stored in the past, retrieval becomes more difficult," explains Sebastian Scholz, adding that forgetting also plays an important role when information already stored is to be updated - as in the example of the new PIN. A further advantage, he says, is that current studies show that we tend to forget negative information about ourselves more easily than positive information. "In other words, forgetting represents a kind of ’immune system for our self-esteem’," Scholz comments. But how do test persons manage to forget certain information - at the push of a button, so to speak - which they had previously received? "Anyone who tries really hard to forget a certain thing achieves the opposite. For that reason, it makes more sense to replace the mental representation of the information to be forgotten with another piece of information."
The processes of remembering and forgetting differ from person to person. A higher capacity in working memory goes hand in hand with an improved ability to successfully suppress information. "Biological factors and a more efficient use of learning strategies may be further reasons for these differences," says Scholz, adding that people also have different associations in a learning process. "For one person, the word ’car’ has a greater relevance than for someone else who doesn’t associate much with the word. But the more someone associates with a word or idea, the better able they are to retrieve this piece of knowledge."
Author: Hanna Dieckmann
This article first appeared in the University newspaper "wissen