title: Alexia for arithmetical signs. A cause of disturbed calculation.
abstract: Asymbolic acalculia is a variety of acalculia characterized by a failure to differentiate the arithmetical symbols. Two patients presenting this disturbance as the only source of their calculating errors are reported. Neither aphasia nor visuo-verbal disconnection could explain the failure to identify the arithmetical signs. This defect is interpreted as an alexia for this particular semiotic system, the arithmetical signs being stripped of their names and of the corresponding computational rules.
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000523:psychology; D002543:Cerebral Hemorrhage / Q000523:psychology; D002561:Cerebrovascular Disorders / Q000523:psychology; D004411:Dyslexia, Acquired / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D010364:Pattern Recognition, Visual