Working Memory Resource Depletion and Spaced Learning

The journal article "Extending Cognitive Load Theory to Incorporate Working Memory Resource Depletion: Evidence from the Spacing Effect" provides an intriguing look into long-term memory development and effective learning principles via spaced practice and cognitive load theory. Chen et al. (2017) describe their experiments as an attempt to explain how "cognitive load theory can be substantially extended by including working memory resource depletion" (p. 484) and how that can affect massed learning and spaced learning successes. Chen et al. (2017) express many times throughout the paper the superiority of spaced learning over massed learning, but admit that there is minimal theoretical basis or research into why the spacing effect is superior. This article and the experiments the authors describe are designed to help fill that gap regarding why the spacing effect is superior to massed learning.   

Chen et al. (2017) begin their article by describing the principles behind long-term memory development compared to working memory. The foundation they build through discussion on cognitive load theory and memory is well written and helps the reader understand their experiments. However, the information becomes muddled regarding intrinsic cognitive load and extraneous cognitive load, and the authors do not tie those two concepts into either the spacing effect or memory capacity (Chen et al., 2017).

 During the description of experiments 1 and 2, Chen et al. (2017) provide a clearly written breakdown of the principles they hope to prove through a detailed account of their investigation. Figure 3 illustrates their design for experiment 1 that gives the reader an easy-to-understand overview of the experimental design they followed. Their description of experiment 2 is also clear and detailed with easy to process illustrations that highlight the nature of how and why conditions were changed between the two experiments and how the authors hoped those changes would add greater validity and clarity to their expected results. 

Chen et al. (2017) provide examples of where their experimental design failed both in terms of delivery and in results. In both cases, the authors are able to impart to the reader a greater degree of honesty to their reporting and experiment design by describing these errors and how they corrected for those errors. First, when describing the first experiment, the authors admit that several test subjects wrote notes that would not have allowed for the correct test of their working memory. Secondly, the authors acknowledge that their experiment does not explain if "working memory depletion is the sole cause of resource depletion or whether there are other possible causes" (Chen et al., 2017, p. 498). In effect, the experiments determine if working memory resource depletion makes massed learning inferior to spaced learning rather than focusing on how or why spaced practice is more effective. 

A weakness of the article that is not addressed is whether or not the testing effect could affect the results of the experiments. Other research has "showed that after 24 h, the average test performance in the study-test condition was better than in the repeated-study condition. This finding suggests that a relatively long retention interval is required before the memory benefit of intermediate testing over restudying emerges" (Delaney et al., 2010, p. 116). The description of the design of the experiments does not exclude the testing effect as having an impact on the results. 

 Chen et al. (2017) state that their results show the benefits of the spacing effect over massed learning, but rather the design provides a "causal explanation of the spacing effect" (p. 497). Additionally, the authors iterate that their experiments help to show that cognitive resource depletion is better classified as working memory depletion in some circumstances. However, again, the experiment regarding working memory resource depletion does not necessarily prove the effectiveness of spacing so much that it shows how memory resource depletion negatively affects massed learning. Although the authors provide a compelling article that demonstrates a case built of incrementally more complex experiments, instead of showing that working memory resource depletion "provides a strong candidate explanation for at least some versions of the spacing effect" (Chen et al., 2017, p. 488), their experiments prove the ineffectiveness of massed learning over spaced learning.

 

References

Chen, O., Castro-Alonso, J. C., Paas, F., & Sweller, J. (2018). Extending cognitive load theory to incorporate working memory resource depletion: Evidence from the spacing effect. Educational Psychology Review, 30(2), 483–501. 

Delaney, P. F., Verkoeijen, P. P. J. L., & Spirgel, A. (2010). Spacing and testing effects. Psychology of Learning and Motivation (Vol. 53, pp. 63–147). Elsevier.