Beyond Context-Transfer Effects: Attenuated Familiarity During Virtual Reality-Based Retrieval Across Different Encoding Modalities.

Whereas the circumstances under which episodic memory benefits from Virtual Reality (VR)-based encoding remain elusive, preliminary findings suggest that the contributions of the underlying retrieval processes might depend on the encoding modality. Previous research indicates that engrams obtained from VR conditions elicit enhanced recollection alongside attenuated familiarity. However, it remains unclear whether this pattern depends on the congruence of the encoding and retrieval contexts. Consequently, this study examined potential context-transfer effects on the electrophysiological correlates of familiarity and recollection after VR-based and PC-based encoding. A source memory paradigm was employed to test the retrieval of objects and their encoding context, i.e., item and source memory under VR conditions. The electrophysiological results indicated attenuated familiarity of PC-based engrams reflected in the frontal old/new effect (FN400), yet the same held true for VR-based engrams. Moreover, a strong old/new effect in the late positive component (LPC) linked to recollection was evident under both conditions. In contrast, the late posterior negativity (LPN), linked to the search for and reactivation of contextual details during retrieval, was observed under neither condition. In summary, the present results indicated comparable contributions of familiarity and recollection to retrieval, independent of the encoding modality, when retrieval occurred under VR conditions. While effects on engrams retrieved without their correct source might, to some degree, depend on context-transfer effects, familiarity was attenuated across encoding modalities. Consequently, the present results demonstrate that disparities between VR- and PC-engrams depend on the combination of encoding and retrieval modalities and extend beyond context-transfer effects.