Expectancy Violation Drives Memory Boost for Stressful Events

Abstract

Stressful events are often vividly remembered. Although generally adaptive to survival, this emotional-memory enhancement may contribute to stress-related disorders. We tested here whether the enhanced memory for stressful events is due to the expectancy violation evoked by these events. Ninety-four men and women underwent a stressful or control episode. Critically, to manipulate the degree of expectancy violation, we gave participants either detailed or minimal information about the stressor. Although the subjective and hormonal stress responses were comparable in informed and uninformed participants, prior information about the stressor abolished the memory advantage for core features of the stressful event, tested 7 days later. Using functional near-infrared spectroscopy, we further linked the expectancy violation and memory formation under stress to the inferior temporal cortex. These data are the first to show that detailed information about an upcoming stressor and, by implication, a reduced expectancy violation attenuates the memory for stressful events.

Stress enhances emotional memory-related theta oscillations in the medial temporal lobe

“…Interestingly, this influence of stress was manifested in reduced confidence for neutral stimuli rather than in increased confidence in memory for emotional events. This finding suggests a stronger priorization of memory based on emotional salience after stress, which is generally in line with earlier findings suggesting that stress or arousal may not only enhance memory for central features of an episode but also reduce memory for more peripheral information ( Kalbe et al, 2020 ; Kensinger et al, 2007 ).…”

Mechanisms of memory under stress

“…for the manifold changes in mnemonic processes that are observed during and shortly after stress. Specifically, the amygdala-induced modulation of hippocampal activity and plasticity-presumably paralleled by facilitating effects of rapid corticosteroid actions directly in the hippocampus (Wiegert et al, 2006)-results in the enhancement of memory formation for the stressful event itself (Kalbe et al, 2020;Sandi et al, 1997;. Notably, this memory enhancement is only observed for information directly relevant to the ongoing stressor, whereas the encoding of information that is present during the stressful episode but not directly relevant to stressor is even reduced (Kalbe et al, 2020;Schwabe and Wolf, 2010).…”

“…Specifically, the amygdala-induced modulation of hippocampal activity and plasticity-presumably paralleled by facilitating effects of rapid corticosteroid actions directly in the hippocampus (Wiegert et al, 2006)-results in the enhancement of memory formation for the stressful event itself (Kalbe et al, 2020;Sandi et al, 1997;. Notably, this memory enhancement is only observed for information directly relevant to the ongoing stressor, whereas the encoding of information that is present during the stressful episode but not directly relevant to stressor is even reduced (Kalbe et al, 2020;Schwabe and Wolf, 2010). The boost in memory formation for the stressful event itself may be driven by the shift toward the SN, which involves also sensory representation areas, known to interact with the hippocampus in forming long-lasting memories of stressful events (de Voogd, 2016).…”

Caring for healthcare providers in COVID-19.

“…Psychological traumas interrupt protective strategies in maladaptive ways, with empirical studies suggesting that dismissing/forgetting past endangerment is more disruptive to future adaptation than preoccupation with past traumas (Crittenden & Heller, 2017; Crittenden & Newman, 2010; Farnfield, 2019; Kim et al, 2014; Kozlowska et al, 2015; Zachrisson & Kulbotten, 2006). This highlights the importance of early identification of providers’ protective strategies, flexibility in deploying different strategies in different contexts, and past psychological traumas so as to assign vulnerable staff to roles that are less likely to provoke trauma responses or, alternatively, to coach them in advance so as to lower arousal (Kalbe, et al, 2020; Kalbe & Schwabe, 2020).…”