DISORDERS of thinking are of primary significance for the diagnosis and prognosis of schizophrenia. Bleuler, Jung, and Kraepelin, among others, described these distortions of association in rich detail and considered them particularly striking manifestations of schizophrenia.
Later investigators studied this disorder of thinking with special tests.4 Bolles and Goldstein,2 using a modification of Weigl's object-sorting test, observed that the patients seemed "impressed by particular uses of the objects presented and do not act in terms of broader categories." Even if the examiner grouped the objects differently, the patients were often unable to verbalize the concepts. These authors concluded that "the characteristic defect of the schizophrenic patients studied was an impairment of... 'abstract behavior.' " Earlier, Vigotsky,14 employing geometric solids varying in volume and color, rather than familiar objects, reached much the same conclusion. Vigotsky's results were verified in an extensive investigation by Hanfmann and Kasanin.7 Wegrocki,16
COHEN BD, SENF R, HUSTON PE. EFFECT OF AMOBARBITAL (AMYTAL) AND AFFECT ON CONCEPTUAL THINKING IN SCHIZOPHRENIA, DEPRESSION, AND NEUROSIS. AMA Arch NeurPsych. 1954;71(2):171-180. doi:10.1001/archneurpsyc.1954.02320380037004