Cross-cultural diagnostic applicability of the Pictogram Test.

The aim of this study was to determine whether the Pictogram Test (PT; Vygostsky, 1960) a test of logical memory that was developed in Russia, is applicable for diagnosing and understanding thought disturbances in schizophrenia within an English-speaking population. Participants included 62 patients with schizophrenia or schizoaffective disorders and 80 community nonpatients from Russia and the United States. We used correlational analysis to organize PT variables into Concrete (CI), Attribute (AI), and Geometric (GI) indexes. Discriminant function analysis revealed that only AI and GI had significant discriminatory power. These indexes correctly classified 91% of English-speaking and 86% of Russian-speaking participants as either patients or nonpatients. Controlling for age and education, multivariate analysis revealed that patients had significantly lower AI and significantly higher GI scores relative to nonpatients, and those differences were similar across languages. These results indicate that the PT can discriminate between patients with schizophrenia or schizoaffective disorders and nonpatients, which suggests that characteristics of the PT could be used to understand the mechanism of logical thinking in patients and nonpatients.