title: Measuring the executive functions in schizophrenia: the voluntary allocation of effort.
abstract: BACKGROUND
  Executive functioning reflects not only what a patient does, but also how he does it or whether he does it at all [Lezak MD. The problem of assessing executive functions. Int. J. Psychol. 17 (1982) 281]. Standard test procedures strongly prompt subjects to certain behavior, so that initiative and the amount of voluntary effort one is willing to invest are therefore not being adequately assessed.
  
  
  METHODS
  We developed the Cognitive Effort Test (CET); a test for executive functioning specifically aimed at measuring subject's free initiatives, and the amount of effort they invest voluntarily. It is a complex planning task, and performance is being judged by three subscales: Initiative, Planning, and Workload. 36 schizophrenia patients and 30 healthy controls were tested with the CET, and a battery of other cognitive tests (executive functioning, memory, attention and psychomotor speed) was added to investigate construct and divergent validity. Negative symptoms were also recorded (predictive validity).
  
  
  RESULTS
  Patients scored below controls on Planning and Workload, but not on Initiative. The CET was significantly related to other tests for cognition but not to negative symptoms. CET Planning and Workload predicted group membership (patients-controls) better than the other tests for executive functioning combined.
  
  
  CONCLUSIONS
  The CET appears to be a clinically useful test that measures an aspect of schizophrenia that is not being assessed by existing tests, presumably the voluntarily allocation of effort.
authors.affiliation: Department of Psychotic Disorders, GGZ-Drenthe, Assen, The Netherlands. m.van.beilen@neuro.azg.nl
authors.forename: Marije
authors.initials: M
authors.lastname: van Beilen
authors.forename: Ed H
authors.initials: EH
authors.lastname: van Zomeren
authors.forename: Robert J
authors.initials: RJ
authors.lastname: van den Bosch
authors.forename: Frederiec K
authors.initials: FK
authors.lastname: Withaar
authors.forename: Anke
authors.initials: A
authors.lastname: Bouma
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention; D016022:Case-Control Studies; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D011594:Psychometrics; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013647:Task Performance and Analysis