Theory of mind is one of the most intensively studied phenomena in the development of schizophrenic symptoms and impairments in social adjustment. Complex theory of mind processing requires both visual and verbal aspects of the social-perceptual and social-cognitive components of mind reading. Reliable assessment methods are considered essential for the proper conduct of research. The current study aims at investigating the psychometric properties of the Theory of Mind Picture Stories Task (ToM PST). Forty-seven patients with schizophrenia were enrolled in the study from three sites. Data from ToM PST were used for computing the consistency, reliability, and internal and construct validity of the test.Our preliminary findings showed less appropriate consistency. Therefore, we attempted to carry out structural changes on the task while preserving its scales and subscales, which measure crucial factors of ToM. The newly structured task has four scales. They show proper consistency (Sequencing: Cronbach's α = 0.70, Theory of a Single Person's Mind: α = 0.74, Switching Between Minds: α = 0.70, Comprehension of Misleading Behaviour: α = 0.67, Total: α = 0.80) with appropriate internal and construct validity, a moderate test-retest reliability over a four-month-course, and a proper inter-rater reliability.
Keywords: Psychometric properties; Schizophrenia; Theory of Mind; Theory of mind task.