Ranschburg effect: what it is and what does it show about memory

The Ranschburg effect, also called Ranschburg inhibition, is a curious memory phenomenon that occurs in an experimental context. It consists of omitting or presupposing words, digits or elements that are very similar to each other and that the brain, a posteriori, interprets as oneself.

The first description of this phenomenon has more than a century of history, although scientific research has not addressed it too in depth. Below we will find out more about how it happens and what factors influence its appearance.

• Related article: "The 10 most important psychological effects"

What is the Ranschburg effect?

The Ranschburg effect is a memory phenomenon that occurs when, upon receiving several repeated or similar stimuli, one is not able to remember all of them.

At an experimental level, this phenomenon occurs when a sequence with several words or numbers is presented. repeated and that, when trying to remember them later, the person tends to make more mistakes or omit elements.

This phenomenon

has been linked to what have been called divination strategies. These strategies would consist in that the person, when he has to remember what has been presented to him, tries to remember trying to guess one of the elements of the sequence.

If that element was similar to another, the person is likely to decide not to say that element, since he will think that, in fact, he is going to be wrong. He thinks that the item he thinks he remembers is actually a repetition of her own making.

The Ranschburg effect can be confused with repetition blindness, although they are not the same. Repetition blindness refers to the inability to remember a repeated item that occurs in a meaningful sequence or set of words. The person completely omits the repeated element or word, since the repetition of it is perceived by the brain as something superfluous.

An example of repetition blindness would be when we read the following sentence: "When she threw the ink there was ink everywhere." This phrase makes sense, and it has a repeated word, in this case "ink." As the brain does not read word for word, it does a quick scan, causing the brain to imagine what it is reading based on main words. In this case, as the word ink is repeated twice, its second appearance is not seen, that is, it is as if we were briefly blind to that word.

• You may be interested in: "What is the forgetting curve?"

Origins of the concept

The Ranschburg effect It is named after its discoverer, the Hungarian psychiatrist Paul Ranschburg, who first described it in 1901. This psychiatrist was especially interested in memory in psychopathological and neurological processes. A year later he gained international attention with the publication of an article in which he further described this phenomenon.

He originally called it homogeneous inhibition, since it is the difficulty of remembering similar or identical elements in a list to be memorized in the short term. Thanks to Ranschburg it was possible to understand the difficulty of remembering lists with elements that resembled, since in lists with different elements, it is more likely that all the elements that have been presented to the subject will be better remembered.

An example

To better understand the Ranschburg effect, we are going to see a practical case in which the phenomenon can occur. Next we are going to see a list of nonsense three letter words with CVC structure.

BEX, DOV, DEX, BOV, DEV, BOX, DOX

This list of words is potentially inducing the Ranschburg effect, basically because they are very similar to each other. There are only two types of initial consonants (B and D), two types of intermediate vowels (E and O) and two types of final consonants (V and X). These seven words are very similar and, because of this, if we were to instruct an experimental subject to remember all seven, it is quite likely that they would be confused. He would omit some of them, thinking that he either makes them up or has already said them.

In contrast, in the following list, where nonsense words with CVC structure also appear, the Ranschburg effect is much less likely to occur.

DEG, VOK, NUX, ZAJ, KIF, BEL, TON

As with the previous list, we are looking at seven three-letter words, but these are clearly different from each other. They all start and end with different consonants, and only the vowels E and O are repeated. Trying to remember these nonsense words is easier, since each of them is striking compared to the others, facilitating their memorization and recall.

Research on this phenomenon

Originally, when this phenomenon began to be approached experimentally, it was suggested that its appearance depended on the simple fact that there were repeated or similar elements in the same sequence, regardless of their position. However, it seems that, In addition to its similarity or repetition, it is the position in the sequence that influences the memory or omission of certain elements.

The Ranschburg effect decreases correlatively as the size of the sequence increases. The more elements, having several that do not resemble each other, the less omission would occur in principle. However, if the repeating or similar items are very close together, no matter how long the sequence is, there will be less chance of the effect occurring Ranschburg.

For example, in the following sequence, in principle, there would be less chance of the Ranschburg effect occurring:

TIK, NET, BET, SET, FAL, GAP, FIS

Instead, in this sequence below there would be a greater chance that the experimental subject missed one of the two similar syllables:

TIK, NET, FAL, BET, GAP, SET, FIS

Repeating or similar items placed at the beginning or end of the sequence improve their detection rate, making the Ranschburg effect less likely. This makes sense because this effect It is counteracted by two other well-known ones in the field of memory psychology, which are the primacy and recency effects.. The primacy is to remember better the things that have been presented at the beginning, while the recency is to better remember what was presented at the end.

• You may be interested in: "Recency effect: what is it and how does it affect memory"

Divination strategies error

Although the term “divination strategies” should not be considered academic, it is the one that we are going to use to refer to the strategies individuals use to try to fully recall a sequence with similar elements or repeated. People, when we try to remember things, we try to fill in the gaps with a bit of confabulation, that is, in a certain way we make up memories.

In the cases of the sequences presented to demonstrate the Ranschburg effect it happens that, as there are elements that are similar or identical, in principle it should be easier for us remember them. That is, as they are alike or the same, we should not invest much effort in remembering something repeated. However, the opposite is the case. As we know that we fill in gaps in our memory, it happens that, when we remember something that gives us the feeling that it looks like something we have already said, we suppose we have made it up, something that many subjects would do.

The other explanation for this phenomenon with respect to divination strategies is that When trying to fill in the gaps, it gives us the feeling that it is not that we are inventing it, but that we have a bad memory of any of the elements. For example, going back to the sequence BEX, DOV, DEX, BOV, DEV, BOX, DOX we have that BEX and DEX are very similar.

It may be the case that, when they try to remind us, we only remember that there was a syllable that had an -EX structure, and we did not remember the consonant in front of it. We are between BEX and DEX, despite the fact that, indeed, there are the two syllables. As we do not remember that there were two and not one, we decided to gamble and say only one of the two syllables, thinking that we have a 50% chance of being right.

Bibliographic references:

• Greene, R. L. (1991). The Ranschburg effect: the role of guessing strategies. Memory & Cognition. 19 (3): 313–317. doi: 10.3758 / BF03211155. ISSN 0090-502X. PMID 1861617.
• Hinrichs, J. V.; Mewaldt, Steven P.; Redding, J. (1973). The ranschburg effect: Repetition and guessing factors in short-term memory. Journal of Verbal Learning and Verbal Behavior. 12 (1): 64–75. doi: 10.1016 / S0022-5371 (73) 80061-1.
• Stuart-Hamilton, I (2006). The Psychology of Aging: An Introduction, Fourth Edition. London: Jessica Kingsley Publishers. p. 104. ISBN 9781843104261.
• Henson, R. (1998). Item repetition in short-term memory: Ranschburg repeated. Journal of Experimental Psychology: Learning, Memory, and Cognition. 24 (5): 1162–1181. doi: 10.1037 / 0278-7393.24.5.1162. ISSN 1939-1285.