Ever since the publishing of his precedent-setting monograph in 1885, Hermann Ebbinhaus’ has been recognised as the first psychologist to experimentally study memory.

The lasting impact of his ideas is evidenced in the fact that they continue to garner scientific interest and have been extensively studied for over a century since their inception.

Ebbinghaus’ ideas constitute the foundations of the discipline of cognitive psychology.

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Hermann Ebbinhaus

What do we learn from Ebbinghaus’ work about memory and language?

In this essay, most of the ideas from his seminal work will be explored.

This includes the two principles of memory and learning that gave rise to the world’s first learning curve.

The forgetting curve as another major discovery and the explanations for forgetting will be mentioned.

Finally, the serial position effect will be looked at which significantly contributed to our understanding of memory.

The Learning Curve

Hermann Ebbinghaus (1885) performed the first scientific study to explore the relationship between practice and learning.

In his study, Ebbinghaus himself read through a list of 16 nonsense syllables (e.g. JEV, ZIF, VAM) for 0, 8, 16, 24, 32, 42, 53 or 64 repetitions.

In order to ascertain how much he had learnt, he waited 24 hours to re-learn the sequence and measured the time it took him to recite the list of 16 syllables without error.

The results of the study illustrate two very important principles of memory and learning.

 

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The Learning Curve: Ebbinghaus, H. (1885). Über das Gedächtnis. Berlin: Duncker & Humblot.

First, there is a linear relationship between time spent learning and amount learnt. The more practice dedicated to learning, the greater the amount that is learnt. This is the learning curve.

Second, he found that distributed learning is much more effective than cramming into a single session.

The Forgetting Curve

In another experiment, Ebbinghaus (1885) learnt lists of 13 nonsense syllables which he kept learning until he was able to repeat them without error.

After a delay, he would re-test himself. He noted that waiting 20 minutes for the first recall trial resulted in substantial drop in performance as a result of forgetting.

Ebbinghaus was curious as to how long it would take to re-learn forgotten information, which led him to introduce the savings method.

The savings method measured the amount of forgetting by determining the amount of trials needed to re-learn the material.

The findings generated a forgetting curve that is non-linear and its shape approximately logarithmic.

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Image: Gleitman, H., Reisberg, D., Gross, J. (2007). Psychology

The curve shows that there is a sharp initial dip in the amount of information forgotten but then the rate of forgetting is much less drastic as it gradually slows down at later stages of retention where the function finally tails off.

The forgetting curve has been proven to be tremendously accurate as a staple finding in understanding forgetting.

In fact, Rubin and Wenzel (1996) confirmed the logarithmic shape of the forgetting curve having analyzed 210 data sets involving various memory tasks.

Autobiographical memories decay at a slower rate

However, Marigold Linton (1975) conducted a study of her autobiographical memories over a five-year period.

Everyday she noted two events and at predetermined intervals she systematically tested her recall of these.

It was found that she lost the ability to remember 5% of the items per year and the forgetting function was linear in nature.

These findings don’t necessarily mean that the forgetting curve is less universal than initially thought.

In fact, this study is evidence for autobiographical memories showing slower forgetting and thus being a major exception to Ebbinghaus’ forgetting curve.

A possible explanation for this is Jost’s (1897) law which upholds that “if two memo traces differ in age but are of equal strength, the older one will decay more slowly over any give time period.” (Eysenck and Keane, 2010, p.233).

The study also illustrates how different results can be generated in more naturalistic settings compared to Ebbinghaus’ artificial laboratory setting.

How does forgetting occur?

But how does forgetting occur?

Ebbinghaus offered possible explanations initially put forth by philosophers of his time.

One of the perspectives, he argued, is that the passing of time causes memory traces to slowly decay until they finally disappear (e.g. Wixted, 2004).

Another perspective emphasises the role of interference caused by new learning. That is, old information that has been in long-term storage can become disrupted by new information that is being committed to memory.

For instance, Baddeley and Hitch (1977) carried out a study where they asked rugby players to recall the names of teams they had played against during the season.

The aim was to find out whether the ability to successfully recall team names was affected more by the passing of time or interference caused by intervening games.

Due to the fact that not all rugby players attended these games for various reasons, for some “2 games back” meant 2 weeks ago and for others it meant 4 weeks ago.

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Baddeley, A.D. & Hitch, G.J. (1977). Recency re-examined, in S. Dornic (Ed.), Attention and Performance VI, pp. 647-665, London: Academic Press.

Such differences allowed the researchers to look at the effect of time on recall ability.

Similarly, Baddeley and Hitch looked at the effect of new learning by comparing players for whom the game a month ago was “3 games back” with players for whom it meant “1 game back.”

It was found that intervening games greatly affected recall and thus interference was established as a more powerful determinant of forgetting than time decay.

Nothing definitive can be said about forgetting

While Ebbinghaus’ contributions have immensely aided our understanding of forgetting, many uncertainties remain.

For instance, although research (e.g. Baddeley & Hitch, 1977) has demonstrated the powerful effects of interference with regards to forgetting, how interference exactly behaves is unclear.

Does interference cause memory traces to compete with one another?

Or are previous memory traces destroyed by other traces?

At this point in time, nothing definitive can be stated as to whether interference and trace decay are mechanisms by which forgetting occurs (Baddeley, 1997).

The Serial Position Effect

One of the topics that continue to be of interest is the serial position curve first discovered by Ebbinghaus, which expresses the relationship between the place of an item in a list (i.e. its serial position) and the ability to recall it.

Interestingly, Ebbinghaus made the observation that some items are recalled better than others, namely the first (primacy effect) and final (recency effect) items.

Ever since its discovery, the serial position effect has had a major impact on the understanding of memory.

It has garnered substantial interest and as a result has been extensively studied for many decades.

One of such studies include Roediger and Crowder (1976) where they asked participants to recall the names of presidents of the United States of America in chronological order of their term of office.

The findings showed that there were pronounced primacy and recency effects in participant recall.

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Roediger III & Crowder (1976). A serial position effect in recall of United States presidents. Bulletin of the Psychonomic Society, 8, 275-278.

Although there was a poor recall of the middle presidents, there was a spike in performance for Abraham Lincoln.

Roediger and Crowder suggested that the primacy and recency effects arise due to the first and last presidents having less neighbors to one side than presidents in the middle.

Also, the anomalous performance of Lincoln was explained by his distinctiveness as a prominent national figure in the history of the country.

Closing Thoughts

What we learnt about memory courtesy of Ebbinghaus’ contributions was explained with the aid of most of his monumental ideas such as the principles of learning, the forgetting curve, explanations for forgetting, and the serial position effect.

What we learnt was that the amount learnt increases with amount of practice, and that distributed learning is more effective than massed practice.

The forgetting curve was mentioned as an idea that immensely aided our understanding of the process of forgetting and the explanations for its occurrence were discussed.

The serial position effect was examined with regards to memory.

However, many uncertainties still surround the process of forgetting and the actual explanation for the serial position effect is still debated.

Though there is significant amount of research supportive of Ebbinghaus’ discoveries, the evidence is still not conclusive enough.

Although there is still much ground to cover within the field of cognitive psychology, Ebbinghaus’ contributions have cemented his legacy as one of the world’s most valuable scientists.

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