Recent work has used a modified version of the well-known laboratory stressor, the Trier Social Stress Test (TSST), to study participant memory for a stressful experience. The paradigm is useful because, unlike most studies examining stress effects on memory, it allows investigators to measure what participants remember about the stressor, not unrelated information. It also presents an opportunity to model other stress-related symptoms, such as intrusive memories, but these have yet to be assessed with this paradigm. Intrusive memories have been notoriously difficult to measure in laboratory settings; most of this research involves participants watching arousing videos and subsequently reporting any intrusions they experience. However, measuring intrusive memories that result from arousing videos is quite dissimilar from measuring intrusive memories that result from a stressful event. Thus, we aimed to replicate and extend previous work by examining the impact of TSST exposure on (1) participant memory for the stressful event, (2) false memories of the stressful event, and (3) intrusive memories related to the stressful event.
Healthy undergraduate students were exposed to the TSST or the friendly-TSST (f-TSST). The TSST required participants to deliver a ten-minute speech in front of two lab panel members as part of a mock job interview; the f-TSST required participants to casually converse with panel members about their interests and hobbies. In both conditions, the panel members interacted with (central) or did not interact with (peripheral) several objects sitting on a desk in front of them. Participants’ heart rate, blood pressure, and anxiety levels were assessed before and after the TSST or f-TSST, and saliva samples were collected to assay for cortisol and alpha-amylase. The next day, participants’ memory for the objects that were present on Day 1 was assessed with recall and recognition tests. We also quantified participants’ intrusive memories for each task by having them complete an intrusive memory questionnaire on Days 2, 4, 6, and 8. Participants exposed to the TSST exhibited greater recall of central objects and fewer falsely recalled objects than participants exposed to the f-TSST. Most importantly, participants exposed to the TSST reported a greater number of intrusive memories related to the speech task. Some measures of intrusive memories in this group persisted for several days after stress exposure. Collectively, our work demonstrates that the modified TSST paradigm is a useful tool to not only study what participants remember about a stressful event but to also investigate characteristics of intrusive memories that may ensue
