A Protocol to Modulate Arousal During Retrieval: Increased Arousal and Short-Term Verbal Memory Modulation Expression

Predicting a stressor's effect during a specific memory phase remains challenging. A mild stressor during memory reconsolidation unexpectedly impaired, rather than enhanced (Coccoz et al., 2013), the long-term expression of a neutral verbal declarative memory (two-trial Rey Auditory Verbal Learning Test (RAVLT; lists of words; Sánchez Beisel et al., 2022)), an effect correlated with increased arousal at retrieval. Are these internal states reinstated during retrieval sessions a key substrate of stress-induced memory impairment? We tested whether this retrieval-induced internal state contributes to stress-related memory impairment by inducing neutral, positive, or negative states before RAVLT retrieval using images from the International Affective Picture System (IAPS) and music. Internal state was assessed with the Self-Assessment Manikin (SAM) after retrieval; memory was measured through free recall, serial position effects, and recognition. Results showed that, effectively, there was an increase in arousal in the negative group (mean difference = −1.57; 95% bootstrap CI: −2.53 to −0.36). However, no significant differences in memory performance were observed across conditions. These findings suggest that the protocol successfully modulated participants' internal states, although this effect did not translate into detectable differences in short-term memory performance.