The spacing effect or how to ensure sustainable learning

Training presented repeatedly and spaced out over time - spacing effect - is a guarantee for sustainable learning

Who has never said to himself: “I am not sleeping tonight, I absolutely must master this file or this course before tomorrow morning”. Most of us have already imposed this marathon of learning or revision in the run-up to exams or an important event. THEMassed learning (working a lot and all at once) will sometimes allow us to be ready enough the next day. But temporarily “having in mind” these notions - learned too quickly - can give us The illusion of mastering them. What about one or two weeks later, or even 6 months later? Have we really learned them?

The spacing effect

Numerous studies have shown that working in massed sessions is less effective in terms of long-term memory than working in spaced sessions [1]. This phenomenon is known as the effect of” Spacing ” or spacing effect [2].

For a memory trace to be strengthened and consolidated, the distribution of learning sessions must be spread over time.. These periods may extend over a few days forencoding simple information. Indeed, some studies show better memorization and better mastery of concepts when the sessions were spaced out over only 4 short sessions compared to a single longer session [3]. But these periods can go up to several months or years for the encoding of more complex information [4]. This is like the training of high-level athletes who perfect their technical skills for years so that they become completely automatic and are perfectly mastered.

This “spacing” effect applies to many types of learning such as learning to conduct interviews [5], to master surgical techniques [6] or even to play video games [7] or on the piano [8]. In addition, the spacing is extremely powerful. Studies have shown that the better this mastery is, the more it is associated with a better transferring from this learning to other contexts [9]. In other words, this knowledge can be used not only in the learning context, but in any other relevant context.

Thus, information presented repeatedly and spaced out over time is better restrained and better controlled than the same information presented in a massed manner. But why such a difference, when the total time spent learning can remain the same in both cases?

The acquisition of a new skill, a process that takes place over time

It seems that this difference is explained in part by one of the fundamental properties of the functioning of our nervous system and in particular of our memory: theencoding And the consolidation By neurons new information does not happen all at once! These biological properties of neurons are shared with many other animal species. The encoding and consolidation of a lasting memory trace in our brain involves a process in several steps that takes place over time.

When we learn new information, it will first be stored in our Short-term memory is the encoding stage. But information stored only in short-term memory remains very labile. The memory trace, i.e. the imprint left on the brain by learning this new information, is fragile and can disappear quickly.

If we want it to be acquired for a long time, our brain must integrate it and store it in our long-term memory: this is the consolidation stage. This step makes it possible to progressively stabilize the new information in our neural networks. It uses biochemical and molecular mechanisms that take time: several hours, or even several days may be necessary before leading to the formation of a memory trace that can easily be re-activated during recall. By training over time, we therefore facilitate the consolidation of information in our long-term memory.. On the other hand, by training in a massed manner, our brain does not have time to stabilize this memory trace. It can therefore be quickly lost.

Spacing, a protection against oblivion

What are the neurobiological mechanisms that explain this effect of “spacing”? Numerous studies in rats have shown that hippocampal neurons are involved in remembering new information and in long-term consolidation processes. The researchers first confirmed that rats following training sessions distributed over time memorized new information more effectively than those following massed sessions [10]. But above all, they showed that the new neurons generated a week before this training session in the hippocampus (also called neurogenesis phenomenon), survived longer. These neurons would therefore appear to be protected and would thus participate in the formation of this more persistent memory trace.

Thus, all this scientific research shows us that it is not by compressing our learning sessions into one that we will have a solid acquisition of our new knowledge. But it is by respecting the functioning of our brain and the consolidation steps necessary to anchor new knowledge that we will be able to better manipulate this information and keep it over time. Respecting regular revisions over time is therefore an excellent way to learn better and to forget less!

‍REFERENCES:

[1] Cepeda, N. J., Pashler, H., Pashler, H., H.,,, H.,, H.,, Vul, E., E., Wixted, J.T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132 (3), 354.
[2] Ebbinghaus, H. (1885). Über das Gedächtnis. New York, NY: Dover.
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[4] Hattie, J. (2008). Visible learning: A synthesis of over 800 meta-analyses relating to achievement. Routledge.
[5] Heidt, C.T., Arbuthnott, K.D., and Price, H.L. (2016). The Effects of Distributed Learning on Enhanced Cognitive Interview Training. Psychiatry Psychol. Law 23, 47—61. doi: 10.1080/13218719.2015.1032950
[6] Andersen, S.A.W., Mikkelsen, P.T., P.T., Konge, L., Cayé-Thomasen, P., and Sørensen, M.S. (2016). Cognitive load in distributed and massed practice in virtual reality mastoidectomy simulation. Laryngoscope 126, E74—E79. doi: 10.1002/lary.25449
[7] Stafford, T., and Dewar, M. (2014). Tracing the trajectory of skill learning with a very large sample of online game players. Psychol. Sci. 25, 511—518. doi: 10.1177/0956797613511466
[8] Simmons, A.L. (2011). Distributed practice and procedural memory consolidation in musicians' skill learning. J. Res. Music Educ. 59, 357—368. doi: 10.1177/0022429411424798
[9] Smith CD and Scarf D (2017) Spacing Repetitions Over Long Timescales: A Review and a Reconsolidation Explanation. Forehead. Psychol. 8:962. doi: 10.3389/fpsyg.2017.00962

[10] Sisti, H.M., Glass, A.L., & Shors, T.J. (2007). Neurogenesis and the Spacing Effect: Learning Over Time Enhances Memory and the Survival of New Neurons. Learning & memory, 14 (5), 368-375.