title: Slowing of information processing in Alzheimer disease:  motor as well as cognitive factors.
abstract: OBJECTIVE
  To use Sternberg's Additive Factor Method to determine whether patients with mild Alzheimer disease (AD) are slow in information processing and/or response execution.
  
  
  METHODS
  We gave an odd-even categorization task to 16 patients with probable mild AD and 17 age-matched healthy controls. We recorded reaction and movement times to stimuli varying for noise, target set size, stimulus-response compatibility, and fore-period interval, to probe the cognitive and motor stages of information processing.
  
  
  RESULTS
  Both groups performed the task accurately, indicating good preservation of odd-even categorization in mild AD. The AD group's reaction times were similar to the controls' across conditions, and not selectively affected in any of the cognitive stages of the Additive Factor Method. However, the AD group's movement times were slower than the controls' across conditions.
  
  
  CONCLUSIONS
  AD patients' performance on a task requiring categorization ability was slowed more by motor than cognitive components of information processing. When evaluating the performance of patients with AD in reaction-time paradigms, we should not attribute group differences solely to differences in cognitive processing. Execution components should also be considered.
authors.affiliation: Neuropsychology Unit, Istituto Di Ricovero e Cura a Carattere Scientifico Fondazione Santa Lucia, Rome, Italy. marialuisa.martelli@uniroma1.it
authors.forename: Marialuisa
authors.initials: M
authors.lastname: Martelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Barban
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Zoccolotti
authors.forename: Maria Caterina
authors.initials: MC
authors.lastname: Silveri
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*