Simulation-Based Mentalizing Generates a “proxy” Self-Reference Effect in Memory

The self-reference effect (SRE) in memory is a cognitive bias thought to depend on functionally specialised mechanisms that enhance memory for self-relevant information. These mechanisms may, however, by engaged by ‘proxy’ when we use our own mental states to simulate those of other people, but clear evidence of memory enhancements linked to such proxy self-reference is lacking. Here, young, healthy adult participants interacted with two virtual partners, one similar and one dissimilar to each participant in terms of their opinions and beliefs. Participants then viewed pairs of objects, and were instructed to pick one either for themselves, for their similar partner or for their dissimilar partner. A surprise memory test followed that required participants to view the object-pairs again and identify which object was chosen, and for whom. Participants were then shown their partners’ object pairs again, and asked to pick the objects that they preferred. Four key findings were observed. Overlap between participants’ own choice and those made for their partner’s was significantly higher for the similar vs. dissimilar partner – revealing participants use of their own preferences to simulate the similar partners. Recollection of chosen objects was significantly higher for self vs. both partners and, critically, significantly higher for the similar vs. dissimilar partner. Finally, we replicated prior findings of enhanced source confusion (here, over object-ownership) between self and the similar partner. These findings suggest that self-reference by proxy enhances memory for non-self relevant material, and we consider the theoretical implications for functional interpretation of the SRE.