Positive modulation of a neutral declarative memory by a threatening social event

• The Virtual-Auditory Panel (VAP) requires only one experimenter.
• VAP induces an increase in cardiovascular, neuroendocrine, sympathetic responses.
• VAP improves memory retention of a recently acquired neutral declarative memory.
• VAP affects memory acquisition improving long term retention.
• VAP affects memory process, alleviating forgetting of a neutral declarative memory.
• Electrodermal activity could be a useful online measure of social threatening.

Memories can be altered by negative or arousing experiences due to the activation of the stress-responsive sympatho-adrenal-medullary axis (SYM). Here, we used a neutral declarative memory that was acquired during multi-trial training to determine the effect of a threatening event on memory without emotional valence. To this end, participants received a new threatening social protocol before learning pairs of meaningless syllables and were tested either 15 min, 2 days or 8 days after acquisition. We first demonstrated that this threatening social situation activates not only the SYM axis (Experiment 1) and the hypothalamus–pituitary–adrenal axis (HPA; Experiment 2), but also, it improves the acquisition or early consolidation of the syllable pairs (Experiment 3). This improvement is not a transient effect; it can be observed after the memory is consolidated. Furthermore, this modulation increases the persistence of memory (Experiment 4). Thus, it is possible to affect memories with specific events that contain unrelated content and a different valence.