Research examining the impact of stress on learning and memory is highly relevant to our understanding of eyewitness memories, traumatic memories, and the etiology of stress-related psychological disorders. Studies in this area have revealed that stress exerts complex effects on cognition that depend on several factors related to the stressor, the learning task, and the participant under investigation (Cadle and Zoladz, 2015, Hidalgo et al., 2019, Schwabe et al., 2022, Shields et al., 2017, Wolf, 2019). A significant limitation in this area of work, however, is that most studies examining the effects of stress on learning and memory have utilized stressors that are extrinsic to the learning task. For instance, investigators may expose participants to a social evaluative stressor, such as the Trier Social Stress Test (TSST) (Wolf, 2019), and then examine its impact on participant memory for a list of words, images, or a film. In such a case, the information being learned is separate from, and often unrelated to, the stress experience (however, see Shields et al., 2022, Smeets et al., 2009 for exceptions). Although this work has helped us understand the basic dynamics of stress-memory interactions, it has by and large failed to reveal what individuals remember about the stress experience itself. This is an important limitation because life frequently requires individuals to recall aspects of stressful events they have experienced (e.g., crimes, traumatic events). Moreover, what some individuals remember about a stressful event can result in highly debilitating psychological conditions, such as post-traumatic stress disorder (PTSD). Clearly, more research dedicated to understanding what individuals remember about a stressful event would be beneficial to the scientific community.

Experimental studies examining participant memory for controlled, laboratory stressors are rare. Research that has investigated individuals’ memories for a stressful event has primarily been field research. For instance, Metcalfe and colleagues examined firefighters’ memory for fires that they had fought (Metcalfe et al., 2019). These investigators found that the firefighters exhibited more accurate memory for central details of the fires than for peripheral details. This is consistent with much of the literature examining the effects of stress on learning and memory (Kensinger, 2009, Kensinger et al., 2007, Levine and Edelstein, 2009) and is adaptive because details that are likely to enhance subsequent survival are those deemed central to a stressful event. Indeed, stress has been shown to turn the prefrontal cortex “offline,” which narrows attention and environmental processing and causes an individual to focus on salient aspects of the task, at the cost of less important details (Arnsten et al., 2015, Cadle and Zoladz, 2015, Henckens et al., 2009, Herten et al., 2017).

Recently, the laboratory of Oliver Wolf modified the traditional TSST paradigm to enable an assessment of participant memory for the stress experience. Typically, the TSST consists of three phases: an anticipatory preparation phase, a speech task, and a mental arithmetic task; the speech and mental arithmetic tasks are performed in front of laboratory panel members and are video recorded (Kirschbaum et al., 1993). The TSST has been used in hundreds, if not thousands, of studies on stress and reliably induces an autonomic and corticosteroid response in participants (Narvaez Linares et al., 2020). Wolf and colleagues modified the paradigm so that participants delivered a longer speech, without the mental arithmetic portion, in front of two laboratory panel members. Importantly, during the speech, there were several office-related objects on a desk in front of the panel members, half of which were actively manipulated by the panel members during the speech (Bierbrauer et al., 2021, Herten et al., 2017, Herten et al., 2017, Ruttgens and Wolf, 2023, Wiemers et al., 2013, Wiemers and Wolf, 2015). The manipulated objects were considered “central” to the stress experience; the remaining objects were considered “peripheral.” Wolf and colleagues then assessed participant memory for the objects. Across several studies, these investigators found that stressed participants had better memory for central objects than for peripheral objects, and their memory for central objects was greater than that demonstrated by participants exposed to a control manipulation.

The modified TSST paradigm developed by Wolf and colleagues marks significant progress in the area of research examining stress-memory interactions. The paradigm can be used to explore factors that impact participant memory for a controlled stress experience, which could aid our understanding of eyewitness memory and the etiology of stress-related psychological disorders. One of the cardinal symptoms of PTSD is intrusive, flashback memories of the traumatic event, and, although some research in humans has shown that emotionally arousing films can result in intrusive memories in healthy participants (Lau-Zhu et al., 2018), there have been few, if any, basic laboratory studies that have quantified intrusive memories in participants exposed to an experimentally-controlled stress manipulation like the TSST. Thus, the purpose of the present study was to replicate the findings from Wolf and colleagues by using their modified TSST paradigm. We also aimed to extend their work by quantifying (1) false memories (i.e., memories of objects not present during the speech task) and (2) intrusive memories of the TSST in participants. Our findings may be relevant not only to understanding what participants remember about a stress experience but also for the validity of using the TSST to study intrusive memory phenomena.