CAN INTENTIONAL SUPPRESSION MODULATE MEMORIES CONSOLIDATED UNDER STRESS?

Negative life experiences are often stressful, and stress enhances memory consolidation, rendering such memories persistent, vivid, and easily triggered by everyday cues. These unwanted memory intrusions can disrupt well-being, particularly when emotionally intense. To cope with such distress, individuals attempt intentional suppression, which involves preventing memory retrieval. The present study investigated whether suppression-induced forgetting (SIF) can modify memories consolidated under stress and their qualitative features (valence, arousal, and vividness), and whether stress during consolidation affects the intentional control of memory intrusions. On Day 1, 121 participants were randomly assigned to a stress or no-stress group. After learning 36 negative cue–scene pairs, participants underwent either an acute stress induction using the Maastricht Acute Stress Test (MAST) or a control procedure. Twenty-four hours later, participants completed the Think/No-Think (TNT) task, during which they were instructed to intentionally recall or suppress the previously learned memories. Results confirmed the effectiveness of the stress manipulation, as indicated by significant physiological and subjective stress responses. Critically, the no-stress group showed a reliable SIF effect, and intrusion frequency decreasing across suppression blocks. In contrast, participants exposed to stress during consolidation showed no evidence of SIF, suggesting that consolidation stress impaired intentional suppression. No group differences were observed in suppression-related changes in valence, arousal, or vividness. However, secondary analyses indicated that SIF predicted greater reductions in vividness specifically in the stress group. Together, these findings provide evidence that acute stress during consolidation disrupts suppression-induced forgetting and suggest that qualitative memory features are relatively resistant to intentional forgetting.