Preference for normal, reversed or chimeric self-faces with neutral emotional expression in patients with schizophrenia and control subjects.

OBJECTIVES: Self-face recognition is one of the most distinctive features in human beings. Disturbances of self-face recognition in people with schizophrenia may reflect the underlying neurobiological and psychological factors of the disorder. Our aim was to establish whether differences in preference for the similarity to the true self-face appearance could be found between patients with schizophrenia and a matched control group.

SUBJECTS AND METHODS: 14 right-handed patients with schizophrenia and 14 control subjects were enrolled. Subjects were photographed, the pictures were converted to black and white, halved vertically, and four faces were used: normal face (NF), mirrored face (MF), face composed from two left halves of the face (LLF) and from two right halves of face (RRF). Four pairs of faces were exposed to subjects and they chose which they felt was closest to their true appearance.

RESULTS: No significant differences for preference were found between the patients and control subjects. Post-hoc analysis of the pooled groups showed a significant difference for preference of NF vs. RRF (20 vs. 8 probands; χ2=5.14, df=1, p<0.05). 18 subjects from the two groups did not change the right-left visual field focus through all four exposures.

CONCLUSIONS: The absence of significant differences for preference for true self-image between schizophrenia patients and control subjects might show that self-face recognition is of little importance from the evolutionary perspective. Additional measurements such as eye-tracking control and random multiple projections of the same pairs of faces would contribute to a more thorough interpretation of the findings in future studies of similar design.