Preliminary Evidence of a Missing Self Bias in Face Perception for Individuals with Dissociative Identity Disorder

Abstract

Failing to recognize one's mirror image can signal an abnormality in one's sense of self. In dissociative identity disorder (DID), individuals often report that their mirror image can feel unfamiliar or distorted. They also experience some of their own thoughts, emotions, and bodily sensations as if they are nonautobiographical and sometimes as if instead, they belong to someone else. To assess these experiences, we designed a novel backwards masking paradigm in which participants were covertly shown their own face, masked by a stranger's face. Participants rated feelings of familiarity associated with the strangers' faces. 21 control participants without trauma-generated dissociation rated masks, which were covertly preceded by their own face, as more familiar compared to masks preceded by a stranger's face. In contrast, across two samples, 28 individuals with DID and similar clinical presentations (DSM-IV Dissociative Disorder Not Otherwise Specified type 1) did not show increased familiarity ratings to their own masked face. However, their familiarity ratings interacted with self-reported identity state integration. Individuals with higher levels of identity state integration had response patterns similar to control participants. These data provide empirical evidence of aberrant self-referential processing in DID/DDNOS and suggest this is restored with identity state integration.

Keywords: Dissociative identity disorder; cognitive processes; complex PTSD; dissociative disorders; perception; posttraumatic stress disorder.

Conflict of interest statement

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship or the publication of this article.

Figures

Fig. 1

Face Familiarity Paradigm example trial. Target and mask types are also depicted. Familiar vs. unfamiliar designations are based on hypotheses for control participants

Fig. 2

Familiarity rating estimated marginal means from the linear mixed effect regression model. Familiarity ratings of the mask are broken out by target stimulus (self, stranger). These are only results for the female masks. The graph on the left is control participants and the graph on the right is a combined sample of all participants with DID/DDNOS. * indicates p < .05, 1 tailed. Error bars are +/− 1 standard error of the mean

Fig. 3

Estimated marginal means of familiarity ratings from the traditional repeated-measures ANOVA with continuous simple effects of identity state integration. Familiarity ratings of the mask are broken out by target stimulus (self, stranger). These are only results for the female masks. The left panel is the estimated marginal means while holding identity state integration scores constant at one standard deviation above the mean (“high integration”) while the right panel is the model holding identity state integration scores constant at one standard deviation below the mean (“low integration”). * indicates p < .05, 1 tailed. N = 28, and error bars are +/− 1 standard error of the mean