title: Comparison of two fMRI tasks for the evaluation of the expressive language function.
abstract: BACKGROUND
  Presurgical evaluation of language is important in patients who are candidates for neurosurgery since language decline is a frequent complication after an operation. Different functional magnetic resonance imaging (fMRI) tasks, such as the verb generation task (VGT) and the verbal fluency task (VFT) have been employed. Our objective was to compare how effective these tasks are at evaluating language functioning in controls (study 1) and patients (study 2).
  
  
  METHODS
  Eighteen controls and 58 patient candidates for neurosurgery (16 patients with temporal lobe epilepsy and 42 patients with brain lesions: 11 astrocytomas, six cavernomas, 14 gliomas, four AVM and seven meningiomas) were recruited in order to compare the activation patterns of language areas as determined by the VGT and VFT.
  
  
  RESULTS
  In both samples, the VGT produced a more specific activation of left Broca's area. In contrast, the VFT yielded a wider and more intense activation of the left Broca's area in controls, as well as other activations in the dorsolateral prefrontal cortex and the striatum. Additionally, both studies showed good agreement on language dominance derived from the tasks, although there was some variability in laterality index scores.
  
  
  CONCLUSIONS
  Both language tasks are useful in evaluation of expressive language. The VGT is a more specific task, while the VFT is more unspecific but activates language-related areas that are not found with the VGT owing to its phonological component. Therefore, each task contributes to the lateralisation and localisation of expressive language areas with complementary information. The advisability of combining tasks to improve fMRI presurgical evaluation is confirmed.
authors.affiliation: Departamento de Psicología Básica, Clínica y Psicobiología, Universitat Jaume I, Avda. Sos Baynat, s/n, 12071, Castellón de la Plana, Spain. asanjuan@psb.uji.es
authors.forename: Ana
authors.initials: A
authors.lastname: Sanjuán
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Bustamante
authors.forename: Cristina
authors.initials: C
authors.lastname: Forn
authors.forename: Noelia
authors.initials: N
authors.lastname: Ventura-Campos
authors.forename: Alfonso
authors.initials: A
authors.lastname: Barrós-Loscertales
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Martínez
authors.forename: Vicente
authors.initials: V
authors.lastname: Villanueva
authors.forename: César
authors.initials: C
authors.lastname: Avila
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000502:physiology* / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000503:physiopathology; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007802:Language; D007807:Language Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D055815:Young Adult