Altered mirroring and self-face processing in schizophrenia: A systematic review

Anomalous experiences at the mirror have been classically described in patients with schizophrenia and conceptualized as "mirror sign". Mirror and self-face-based paradigms offer a unique window into the experiential and cognitive architecture of self-disturbances in schizophrenia, yet empirical findings in this area remain scattered and heterogeneous.

This systematic review synthesizes experimental studies investigating mirror, self-face recognition, and enfacement-illusion tasks in individuals with schizophrenia or at clinical high-risk for psychosis. Four electronic databases (MEDLINE, Embase, PsycInfo, and CINAHL) were searched with the keywords "Schizophrenia" OR "Psychosis" AND "Enfacement illusion" OR "Mirror gazing" OR "Double mirror" OR "Self face recognition" from inception until 31 December 2024.

The search identified 16 experimental studies. Patients consistently exhibited impairments in self-face recognition, altered self-other boundary processing, and increased anomalous experiences during mirror exposure. Illusion-based paradigms revealed attenuated typical enfacement effects alongside heightened misattribution tendencies, suggesting instability in multisensory integration. Mirror-gazing tasks elicited frequent perceptual distortions and self-estrangement phenomena, in line with phenomenological accounts of diminished self-presence. Clinical correlates were generally weak and inconsistent, although some studies indicated associations with positive symptoms and anomalous self-experiences. Methodological quality was overall low, with common limitations including small sample sizes, insufficient blinding, and heterogeneous outcome measures.

Evidence may preliminary support the view that schizophrenia involves fundamental alterations in the dynamic integration between embodied and reflective self-representations. Mirror tasks could provide a promising experimental platform to probe these vulnerabilities, but more rigorous, standardized, and longitudinal research is needed to clarify their diagnostic and mechanistic relevance.