Emotional enhancement and asymmetric context congruency effects for incidental memories of 2D and VR scenes

Abstract Virtual reality (VR) has become more affordable and is increasingly used for therapeutic and educational purposes where it is important to transfer learned experiences to the real world. But is it worth switching from conventional 2D displays to VR to strengthen such learning effects? Here, we investigated how well incidentally learned emotional and neutral scenes, encoded either in VR or as a conventional 2D presentation (encoding context VR, 2D), could be recognized in congruent or incongruent presentation contexts (retrieval context VR, 2D). Using a 3 × 2 × 2 mixed design, 60 participants viewed (and incidentally encoded) emotional and neutral scenes in VR and as 2D video. After 24 h, 30 participants performed an unannounced old-new judgment task in 2D, while the others completed it in VR. 2D-encoded scenes were recognized better in the congruent 2D than in the incongruent VR context. Context congruency effects were less pronounced for VR-encoding. On average, participants reliably recognized VR-encoded scenes in the incongruent 2D retrieval context. Participants retrieved emotional scenes better and more confidently than neutral ones, independent of encoding context. However, scenes experienced in VR were more likely to be perceived as emotional than when the same scenes were viewed as 2D video. Taken together, the presentation mode of a scene (2D, VR) served as a contextual mnemonic aid, mainly for 2D-encoded scenes. Overall, VR-encoded scenes were less dependent on context congruency effects, suggesting a reduced sensitivity to the retrieval context rather than a direct transfer advantage. Finally, VR-encoding increased the likelihood that the content would be perceived as emotional, suggesting its potential as a useful educational and therapeutic tool.