STRANGE-FACE-IN-THE-MIRROR ILLUSIONS: SPECIFIC EFFECTS ON DEREALIZATION, DEPERSONALIZATION, AND DISSOCIATIVE IDENTITY

Anomalous strange-face illusions (SFIs) are produced when mir ror gazing under a low level of face illumination. In contrast to past studies in which an observer’s task was to pay attention to the reflected face and to perceive potential facial changes, the present research used a mirror gazing task (MGT) that instructed participants to fixate their gaze on a 4-mm hole in a glass mirror. The participants’ eye-blink rates were thus measured without priming any facial changes. Twenty-one healthy young indivi duals participated in the MGT and a control panel-fixation task (staring at a hole in a gray non-reflective panel). The Revised Strange-Face Questionnaire (SFQ-R) indexed derealization (deformations of facial features; FD), depersonalization (bodily face detachment; BD), and dissociative identity (new or unknown identities; DI) scales. Mirror-fixation increased FD, BD, and DI scores compared to panel-fixation. In mirror- f ixation, FD scores revealed fading specific to facial features, distinct from “classical” Troxler- and Brewster-fading. In mirror- f ixation, eye-blink rates correlated negatively with FD scores. Panel-fixation produced low BD scores, and, in a few partici pants, face pareidolias as detected on FD scores. Females were more prone to early derealization and males to compartmenta lization of a dissociative identity. SFQ-R may be a valuable instrument for measuring face-specific dissociation (FD, BD, DI) produced by MGT. Use of MGT and panel-fixation task for differ ential diagnoses between schizophrenia and dissociative iden tity disorder is discussed.