Pure misallocation of “0” in number transcoding: A new symptom of right cerebral dysfunction

• Published in: Brain and cognition Vol. 60; no. 2; pp. 128 - 138
• Main Author: Furumoto, Hideharu
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.03.2006; Elsevier
• Subjects: Aged; Aged, 80 and over; Agraphia - complications; Agraphia - physiopathology; Arabic numerals; Biological and medical sciences; Brain Hemisphere Functions; Cerebral Cortex - physiology; Cerebral Cortex - physiopathology; Cognition Disorders - complications; Cognition Disorders - physiopathology; Cognition. Intelligence; Dyslexia - complications; Dyslexia - physiopathology; Female; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Handwriting; Humans; Intellectual and cognitive abilities; Language; Male; Mathematics; Middle Aged; Neurological Impairments; Number transcoding; Numbers; Oral Reading; Patients; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Pure misallocation of “0”; Reading; Reference Values; Right hemisphere; Set theory; Verbal Behavior - physiology; Writing Ability; Pure misallocation of “0”; Arabic numerals; Set theory; Number transcoding; Right hemisphere; Human; Healthy subject; Number; Dysfunction; Central nervous system; Cognition; Japanese; Comparative study; Encephalon
• ISSN: 0278-2626; 1090-2147
• DOI: 10.1016/j.bandc.2005.10.002

To account for the mechanism of number transcoding, many authors have proposed various models, for example, semantic-abstract model, lexical-semantic model, triple-code model, and so on. However, almost all of them are based on the symptoms of patients with left cerebral damage. Previously, I reported two Japanese patients with right posterior cerebral infarction showing pure misallocation of “0” (omission: “40265” → “4265,” addition: “107” → “1007,” transposition: “4072” → “4702”) both in writing and oral reading of Arabic numerals. To examine whether the pure misallocation of “0” is commonly observed in patients with right cerebral damage, I investigated writing and oral reading of Arabic numerals in 18 patients with right cerebral damage and 16 healthy controls. All patients with right cerebral damage showed pure misallocation of “0” both in writing and reading. The pure misallocation of “0” due to right cerebral damage cannot be explained by current models. It may be more useful to explain the phenomenon by regarding an Arabic numeral as graph on a two-dimensional plane composed of two axes (place-holding values and digits).