Mirror-gazing illusion more intense in schizophrenia
MedWire News: Patients with schizophrenia report more intense perceptual illusions during the mirror-gazing task than do mentally healthy people, report researchers who also found that the patients were more likely to believe their illusions were real.
Study co-author Stefano Zago (University of Milan, Italy) and colleagues say the findings reflect underlying ego dysfunction and body dysmorphic disorder in schizophrenia.
Reporting in Schizophrenia Research, the team notes that gazing at one's own reflected face at low illumination can lead to apparitional experiences termed "strange-face in the mirror" illusion. No study has previously investigated mirror gazing in schizophrenic patients, who already exhibit delusions, hallucinations, and self-misattribution.
Zago et al therefore devised a study to compare strange-face apparitions in response to mirror gazing in 16 patients with schizophrenia and 21 mentally healthy controls. Participants underwent a 7-minute mirror-gazing test, after which they completed a specifically designed questionnaire asking them to describe strange-face perceptions.
The researchers found a number of differences between patients and mentally healthy controls.
During the 7-minute task, patients on average perceived a greater total number of strange-faces than controls, at 2.8 versus 1.5.
The types of strange faces also differed between patients and controls. Hugely deformed features were reported by all patients and 71% of controls, archetypal faces by 50% of patients and 19% of controls, and monstrous faces by 88% of patients and 29% of controls. Patients' archetypical and monster faces were usually satanic beings.
Furthermore, on Likert-type scales, patients tended to report greater intensity of apparitions and were more likely to report that they felt real than controls.
Indeed, mentally healthy individuals always felt dissociative experiences during strange-face apparitions and never identified with them.
Collectively the findings suggest that strange-face apparitions in schizophrenia can be produced by ego dysfunction, body dysmorphic disorder, or by misattribution of self-agency, Zago et al assert.
They conclude by saying that the mirror task may actually help in completing the standard assessment of patients with schizophrenia, independently of hallucinatory psychopathology.
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By Andrew Czyzewski