Retrieval Practice and Stress

Retrieval Practice and Stress

School can be stressful, and 2020 has been a particularly stressful year for many of us. So, for this week’s blog, I thought I would write about retrieval practice and stress. Fortunately, I get to share some good news! 

Prior research has shown that acute stress can hinder our ability to retrieve information. Acute stress is stress that comes from a specific event.

(Note: Acute stress is different from chronic stress, where our exposure to stress hormones is repeated and relatively constant. For more information on acute and chronic stress, see this page through the Centre for Studies on Human Stress. I also really like this 3-minute video with Robert Sapolsky on psychology and stress. And, if you really want to commit to learning more about stress and health, Robert Sapolsky has a book called Why Zebras Don’t Get Ulcers: Stress and Health, and a 90-minute lecture on YouTube about the topic. He is extremely knowledgeable, engaging, and funny!)

Acute stress getting in the way of retrieving information can be pretty bad for student learning. If we are experiencing stress before an important test, either due to the test or because of something else, we might be less likely to be able to retrieve what we have learned thus decreasing our performance on the important test! 

Fortunately, there is some evidence to suggest that retrieval practice might be able to protect against memory inhibition that we might experience while stressed (1). In a study published in Science, a very high-profile peer-reviewed publication, Amy Smith and colleagues (2016) investigated retrieval practice and stress. They had four groups of participants:

  1. retrieval practice plus not stressful activity

  2. retrieval practice plus a stressful activity

  3. restudying plus a not stressful activity

  4. restudying plus a stressful activity

To start, they had all participants study nouns and images. While these are considered basic materials, they help the researchers determine cause and effect relationships in the lab to classroom model (2). Then, some of the participants engaged in retrieval practice where they recalled as many as they could remember across a couple of trials, while the other participants restudied the items across a couple of trials. (There was some nuance to the way they had participants study and either restudy or practice retrieval, but it is not central to the main point here.) After this learning phase, they left the lab.

Twenty-four hours later, everyone returned. The participants that were assigned to the stressful activity conditions were asked to give speeches and solve math problems in front of two judges and three of their peers. This sounds incredibly stressful to me, and a lot of other research confirms people find this stressful. Smith and colleagues took some physiological measures to confirm that the participants were stressed. The other participants just completed a simple not stressful activity instead. The participants’ memory was tested immediately after the start of activities, and after 25 minutes.

Here are the main takeaways from the results:

  1. Overall, retrieval practice led to greater performance than restudying.

  2. For the group that restudied, stress did reduce memory performance. The acute stress did not affect the participants’ ability to retrieve what they learned instantaneously. However, within 25 minutes their performance declined if they were stressed compared to when they were not stressed.

  3. For the group that practiced retrieval, stress did not reduce memory performance, even 25 minutes later.