Retrieval Practice Protects Your Memory

A new article in Science magazine from Prof. Ayanna Thomas’ research group is one that every O Chem student should look at. The article doesn’t contain any chemistry, but it contains some potentially valuable insights into becoming a more successful O Chem student.

The article is titled “Retrieval practice protects memory against acute stress” (Smith et al., Science, 25 Nov 2016, DOI 10.1126/science.aah5067) and describes scientific evidence that you can build stronger memories of words and images if you go about it the right way.

The authors introduce their study by pointing to numerous studies that show stress impairs memory retrieval. There is also evidence that the stress hormone, cortisol, affects brain regions that are connected with retrieval of memories.

The authors then comment on different strategies that people use to encode (make) memories. These strategies include reading the words or images over and over again (“rereading” or “restudying“), constructing mental images to accompany words and images (“mental imagery“), drawing diagrams that show relationships between concepts one wants to recall (“concept mapping“), converting lists of items into short-hand abbreviations or mnemonics (“keyword mnemonic“), and simply trying to recall as many items from a list as possible, either in writing or orally (“retrieval practice“). The authors point to research that says, although rereading/restudying is often the method-of-choice reported by people who have been given a memorization task, it is a poor learning strategy because it creates relatively weak memories. Retrieval practice, which you might view as “giving yourself a practice test,” seems to produce memories that are as strong, or even stronger, than those achieved with other study techniques.

The authors, therefore, decided to investigate for themselves whether retrieval practice was superior to rereading/restudying, and also whether memories that were built using these techniques responded differently to the corrosive effects of stress.

The study described in the article involved 120 participants who were divided into two groups, a restudy (SP) group and a retrieval practice (RP) group. Each participant was expected to memorize 60 items, 30 words (nouns) plus 30 images (of nouns). The SP group was allowed to look at (“restudy”) the 60 items a second time, while the RP group was asked to test themselves by writing down as many items as they could recall in a fixed amount of time (“practice tests” were not graded so RP participants never learned whether they had written down correct items or what they had left out). Finally, both groups were divided again into a control set (non-stressed) and a “stressed” group (read a detailed description of the methodology here), and the participants were tested to see how many items they could recall.

The researchers found that:

  • SP participants, the ones who got to look at the list a 2nd time, actually recalled fewer items than RP participants, the ones who took an ungraded practice test. Conclusion #1: RP is a superior method for making memories;
  • Stressed SP participants recalled fewer items than non-stressed SP participants. Conclusion #2: the corrosive effect of stress on memories is real, at least for the SP participants;
  • Stressed RP participants recalled more items than all SP participants (stressed and non-stressed) and essentially gave the same performance as non-stressed RP participants. Conclusion #3: RP learning builds memories that resist stress.

Application to O Chem

Self-testing retrieval practice is simple and straightforward. Suppose your notes for a chapter list 5 nucleophiles that react with alkyl halides (or 5 reagents that oxidize alcohols, or 5 catalysts for hydrogenating alkenes), instead of reading this list over and over again (rereading), you should engage in retrieval practice (RP) by giving yourself a simple test: draw as many of the 5 nucleophiles as you can. If you can only draw 3 nucleophiles, go back to your notes to find the 2 missing items, then test yourself again. Once you can pass the test (draw all 5), work on something else for awhile, and then come back a little later and give yourself another “nucleophile” RP test.

You can also make this a little more elaborate with good effects: test yourself by trying to draw 5 reactions, where each reaction uses a different nucleophile, and each reaction shows a chemical equation with reactants and products.

Or, step it up a little more, draw 5 mechanisms. Or, rank the 5 reactions in terms of speed. With a little imagination, you can practice “retrieval” with almost any type of O Chem information.

Closing thoughts

  • After Smith et al. published their article, Science published a little pushback from some advocates of concept mapping. Here are links to this comment, and to Smith et al.’s response.
  • 4 years earlier Science had published an article that compared retrieval practice to “elaborative studying with concept mapping” and found that retrieval practice was superior. See “Retrieval Practice Produces More Learning than Elaborative Studying with Concept Mapping” (Karpicke & Blunt, Science, 11 Feb 2011, DOI 10.1126/science.1199327)
  • Want to see more Chem 201_202 posts about study habits? Select Study habits & Distractions from the Categories menu in the sidebar. (A “tag” word cloud is on its way…)
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