RESUMO
OBJECTIVES: Disturbance in self-experience has been considered to be a core feature of schizophrenia. Evidence from mirror face-recognition tasks supports the connection between self-face recognition and self-awareness which is a part of self-experience. The aim of this study was to investigate the self-other boundary recognition using morphed face pictures in patients with schizophrenia. METHODS: Twenty-one patients with schizophrenia and twenty-three healthy controls completed the self-face recognition task that consisted of various morphed pictures. Participant's own picture was morphed with each of three different, unknown, gender-matched facial identities in steps of 10% ; each pair producing 11 images with graded blending of facial features. Thirty-three images in total were randomly presented as stimuli in a run, which was repeated three times. Participants were instructed to choose whether the stimulus was self-face or not. RESULTS: Self-face proportion was significantly lower in the schizophrenia group at both recognition start point I and II (33.33% vs. 53.04%, p<0.001 ; 61.43% vs. 70.87%, p=0.01, respectively). Using the mean value of each recognition start point in the control group, we calculated the difference in self-face proportion for each individual with schizophrenia. There was a significant correlation between the degree of this difference and total Scale for the Assessment of Negative Symptoms (SANS) score at recognition start point I (r=0.507, p=0.019). CONCLUSION: The difference in self-other boundary recognition in this study may account for self-disturbance of schizophrenia. Its correlation with SANS total score may reflect the shared nature of persistent disturbance between the disturbance in self-experience and the negative symptom.