title: [The functional independence of lexical numeric knowledge and the representation of magnitude: evidence from one case].
abstract: BACKGROUND
  The ultimate purpose of cognitive neuropsychology is to find out how normal cognitive processes work. To this end, it studies subjects who have suffered brain damage but who, until their accident, were competent in the skills that are later to become the object of study. It is therefore necessary to study patients who have difficulty in processing numbers and in calculating in order to further our knowledge of these processes in the normal population.
  
  
  OBJECTIVE
  Our aim was to analyse the relationships between the different cognitive processes involved in numeric knowledge.
  
  
  METHODS
  We studied the case of a female patient who suffered an ischemic infarct in the perisylvian region, on both a superficial and deep level. She presented predominantly expressive mixed aphasia and predominantly brachial hemiparesis. Numeric processing and calculation were evaluated. The patient still had her lexical numeric knowledge but her quantitative numeric knowledge was impaired. These alterations in the quantitative numeric knowledge are evidenced by the difficulties the patient had in numeric comprehension tasks, as well as the severe impairments displayed in calculation.
  
  
  CONCLUSIONS
  These findings allow us to conclude that quantitative numeric knowledge is functionally independent of lexical or non-quantitative numeric knowledge. From this functional autonomy, a possible structural independence can be inferred.
authors.affiliation: Area de Psicología Básica, Departamento de Psicología, Universidad de Huelva, Huelva, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: Salguero-Alcañiz
authors.forename: J A
authors.initials: JA
authors.lastname: Lorca-Marín
authors.forename: J R
authors.initials: JR
authors.lastname: Alameda-Bailén
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology; D003072:Cognition Disorders / Q000503:physiopathology*; D032882:Comprehension; D005260:Female; D006801:Humans; D019359:Knowledge; D008433:Mathematics; D009483:Neuropsychological Tests