Task-induced transient depersonalization- and derealization-like experiences: a comparative examination of mirror gazing and fixed attention tasks

Depersonalization (DP) and derealization (DR) are dissociative experiences involving altered bodily self-experience and diminished felt reality of the external world. Although various paradigms have been used to induce transient DP-/DR-like experiences experimentally, their relative induction profiles remain unclear. The present study compared Mirror Gazing Task (MGT) with a closely matched Fixed Attention Task (FAT) to characterize task-induced DP-/DR-like experiences in non-clinical adults. Fifty-four participants completed MGT, FAT, Baseline, Break, and a follow-up assessment. During MGT and FAT, participants gazed either at their own face in a mirror or at a black dot on the wall, reported altered visual perception and transient DP-/DR-like experiences using real-time button presses, and completed retrospective post-condition ratings on the DP and DR subscales of the State Scale of Dissociation (SSD-DP and SSD-DR). Both MGT and FAT increased SSD-DP and SSD-DR relative to Baseline, Break, and the follow-up assessment. SSD-DP was higher following the MGT than following the FAT, whereas SSD-DR did not clearly differ between tasks. Online button-press indices of transient DP-/DR-like experiences did not show a clear task difference. These findings suggest a partly shared rather than fully selective induction profile: DR-like elevations appeared more closely linked to contextual features shared by both tasks, whereas the relative advantage of MGT for DP-like experience was clearest in retrospective measures and may be linked to mirror-based self-focus and self-face-related processing. Overall, MGT and FAT provide useful but limited experimental access to transient DP-/DR-like experiences in non-clinical samples.