title: A case of 'task-switching acalculia'.
abstract: In this study we describe a patient (FR) with left frontal lesions due to a cerebrovascular disorder of embolic origin. Beyond a general slowness, FR showed deficits in simple multiplication only when problems were presented in a mixed operations list (multiplication, addition, and subtraction), while no such deficits were observed for the same multiplication problems in blocked presentation. Deficits were restricted to trials directly affected by a switch (increased switch costs), but not to subsequent trials (no increased mixing costs). Thus, we provide the first detailed description of a condition which could be termed 'task-switching acalculia' in a stroke patient. This case highlights the need for mixed operation lists in the diagnosis of acalculia.
authors.affiliation: Abteilung Klinische Linguistik, Institut für Germanistische Sprachwissenschaft, Philipps-Universität Marburg, Germany. domahs@staff.uni-marburg.de
authors.forename: Frank
authors.initials: F
authors.lastname: Domahs
authors.forename: Thomas
authors.initials: T
authors.lastname: Benke
authors.forename: Margarete
authors.initials: M
authors.lastname: Delazer
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D056344:Executive Function / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008433:Mathematics; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time; D020521:Stroke / Q000150:complications* / Q000175:diagnosis; D014057:Tomography, X-Ray Computed / Q000379:methods; D014796:Visual Perception / Q000502:physiology